GitNexus/ARCHITECTURE.md
Gergő Magyar a7b3fa1b81
feat(csharp): migrate C# to registry-primary scope-resolution (Closes #934) (#1019)
* feat(csharp-scope): unit 1 — scope query + captures orchestrator

First slice of the C# scope-resolution migration (issue #934, RFC #909
Ring 3). Closes `Unit 1` of
docs/plans/2026-04-21-004-feat-csharp-scope-resolution-plan.md.

Adds:
- src/core/ingestion/languages/csharp/query.ts — tree-sitter scope
  query covering compilation_unit, namespace (block + file-scoped),
  class-like (class/interface/struct/record/enum), method-like
  (method/constructor/destructor/local_function/operator), property
  and field declarations, using directives, type bindings (parameter
  annotations, local variable annotations, constructor inference,
  invocation alias), and references (free call, member call including
  null-conditional, constructor call, member write).
- src/core/ingestion/languages/csharp/captures.ts — pass-through
  orchestrator mirroring python/captures.ts. Import decomposition
  (Unit 2), receiver-type-binding synthesis (Unit 3), and arity
  metadata synthesis (Unit 5) stub out for future units.
- src/core/ingestion/languages/csharp/cache-stats.ts — PROF
  instrumentation mirror of python/cache-stats.ts.

Design notes:
- Return-type / field-type / property-type captures deferred.
  tree-sitter-c-sharp does not expose these under a clean named field
  that pattern-matches. When Unit 7 parity gate surfaces a gap, add
  positional patterns or a post-hoc extractor lookup.
- object_creation_expression with qualified_name type — the qualified
  name itself is the reference text; captured as a whole via a
  dedicated tag so interpretation in later units can split namespace
  + name.
- Null-conditional calls use positional descendant patterns because
  tree-sitter-c-sharp's member_binding_expression and
  conditional_access_expression don't expose named fields.

Coverage:
- 23/23 new unit tests in
  test/unit/scope-resolution/csharp/csharp-captures.test.ts cover
  every capture tag. Confirmed against tree-sitter-c-sharp via the
  probe-script loop during development; grammar drift would surface
  as a capture-shape assertion failure.
- tsc --noEmit clean.

No changes to shared infrastructure. Resolver wiring + registration
land in Unit 6.

* fix(csharp-scope): capture null-conditional receiver + operator decls

Adversarial review surfaced two Unit 1 bugs that would silently
corrupt the graph once C# is flipped on the scope-resolution path:

- `obj?.Save()` only emitted @reference.name, so receiver-bound
  resolution downgraded to the free-call fallback and could mis-link
  to an imported `Save`. Capture the conditional_access_expression
  receiver under @reference.receiver.
- `operator_declaration` had @scope.function but no @declaration.method
  owner, so calls inside operator bodies were attributed to the
  enclosing class and the operator itself disappeared from method
  lookup. Capture the operator token as @declaration.name (downstream
  csharpMethodConfig normalizes to op_Addition etc.).
- `conversion_operator_declaration` was missing from both scope and
  declaration sets. Added with the target type as the name anchor.

Arity metadata for overload resolution remains deferred to Unit 5 and
gated behind Unit 7's parity flip, as documented in captures.ts.

* chore(scope-resolution): drop unused python/scopes.scm sibling

The file was documentation-only — the authoritative scope query is
the embedded `PYTHON_SCOPE_QUERY` constant in `python/query.ts`.
Nothing loaded the `.scm` at runtime, so it drifted from the code.
Remove it and update the four doc comments that pointed at it:

- language-provider.ts: "scopes.scm query" → "scope query (embedded
  in each language's query.ts)".
- languages/python.ts: capture-vocabulary pointer → query.ts.
- python/query.ts header: drop the "edit both together" note.
- python/receiver-binding.ts: "keeps the .scm declarative" → "keeps
  the embedded scope query declarative".
- scope/walkers.ts: "Python's scopes.scm" → "Python's scope query".

Historical plan docs under docs/plans/ still reference scopes.scm but
are frozen artifacts, not living documentation. C# never had a .scm
sibling, so no action needed there.

* feat(csharp-scope): Unit 2 — import interpret + target resolver

Adds the three files Unit 2 of the C# scope-resolution plan calls for:

- `import-decomposer.ts` — inspects each `using_directive` node and
  synthesizes `@import.kind/source/name/alias` markers. Kinds:
    `namespace`  — `using X;` / `using X.Y.Z;`
    `alias`      — `using Alias = X.Y.Z;`         (generics stripped)
    `static`     — `using static X.Y;`
  `global using` maps to namespace (plan's deferred decision); the
  `global::` qualifier is stripped before emitting.
- `interpret.ts` — reads the markers and builds `ParsedImport`. Static
  using maps to `kind: 'wildcard'` since it brings members into
  unqualified scope; Unit 4's merge-bindings tiers wildcards lowest.
  Also provides `interpretCsharpTypeBinding` with nullable/single-arg
  generic/qualifier stripping so receiver-typed resolution sees the
  concrete class name.
- `import-target.ts` — suffix-match adapter returning a single primary
  file. Cross-file partial-class aggregation runs later at graph-bridge
  time (Unit 6). The csproj-based `resolveCSharpImportInternal` stays
  on the legacy path until Unit 7's parity gate surfaces a gap.
- `captures.ts` routes `@import.statement` matches through the
  decomposer so the interpreter sees the markers it needs.

Tests cover every using flavor + resolution edge cases. 38/38 scope-
resolution C# unit tests pass; tsc clean.

* feat(csharp-scope): Unit 3 — simple hooks (binding/import/receiver)

Adds simple-hooks.ts mirroring Python's pattern:

- `csharpBindingScopeFor` — delegates to innermost (block scope is
  already captured by @scope.block in the query).
- `csharpImportOwningScope` — binds `using` inside a namespace to that
  namespace's scope so imports don't leak into sibling namespaces.
  File-level using delegates to module. Function-body using (not legal
  C# but possible from malformed input) attaches to the function.
- `csharpReceiverBinding` — looks up `this` / `base` in the function
  scope's type bindings; returns null for statics, free functions, and
  non-Function scopes. `this` / `base` synthesis itself is deferred to
  a follow-up (matches Python's receiver-binding.ts pattern).

9 new tests pin delegation semantics. 47/47 C# scope-resolution unit
tests pass; tsc clean.

* feat(csharp-scope): Unit 4 — mergeBindings (using precedence)

Three-tier shadowing, same shape as Python's LEGB merge:
  0: local      — class members, locals, parameters
  1: using      — namespace / named / reexport (equal tier; compiler
                  requires explicit qualifier if two using collide)
  2: wildcard   — `using static X.Y;` static-member imports

Within the surviving tier, de-dup by DefId (last-write-wins) so a
re-declared `using` cleanly replaces its earlier binding. Explicit
interface implementations bind under their qualified name in the
extractor layer, so they don't collide with plain simple names here.

7 new tests pin precedence + dedup semantics. 54/54 C# scope-resolution
unit tests pass.

* feat(csharp-scope): Unit 5 — arity metadata synthesis + compatibility

Adversarial review flagged overload narrowing as a blocker for the Unit
7 flip. This lands the declaration-side metadata; callsite-side arity
synthesis is a separate gap we'll address if the parity gate surfaces
overload misresolution.

- `arity-metadata.ts` — reads `csharpMethodConfig.extractParameters`
  and produces `{ parameterCount, requiredParameterCount,
  parameterTypes }`. `params` variadic collapses parameterCount to
  undefined (matches Python's `*args` treatment) and appends a literal
  `'params'` marker to parameterTypes so the compatibility hook can
  detect it without re-reading the AST. Default-valued parameters
  contribute to optionalCount → requiredParameterCount = total − optional.
- `arity.ts` — `csharpArityCompatibility(def, callsite)` returns
  compatible / incompatible / unknown. Mirrors Python's three-verdict
  shape so the central registry's arity filter works without adapter
  logic per-verdict.
- `captures.ts` — on every @declaration.method / @declaration.constructor
  / @declaration.function match, synthesize
  @declaration.parameter-count, @declaration.required-parameter-count,
  and @declaration.parameter-types captures. Covers method_declaration,
  constructor_declaration, destructor_declaration, operator_declaration,
  conversion_operator_declaration, and local_function_statement.

12 new tests: 5 on captures-side synthesis (method + params + types +
variadic + constructor + local function), 7 on the compatibility hook.
66/66 C# scope-resolution unit tests pass; tsc clean.

* feat(csharp-scope): Unit 6 — wire csharpScopeResolver + register

Creates the public barrel (index.ts) and ScopeResolver (scope-resolver.ts)
and plumbs them into the provider + registry:

- `languages/csharp/index.ts` — re-exports the hook entry points and
  documents the 8 known limitations of the registry-primary path
  (csproj-driven namespace resolution, multi-file namespace expansion,
  type-based overload resolution, nested generics, dynamic, preprocessor
  branches, cross-file global using, expression-bodied members).
- `languages/csharp/scope-resolver.ts` — ScopeResolver shape mirroring
  Python's. `isSuperReceiver` matches the literal `base` keyword.
  `fieldFallbackOnMethodLookup: false` since C# is statically typed
  — the type-binding layer already produces precise owner types;
  `propagatesReturnTypesAcrossImports: true` since signatures are
  authoritative.
- `languages/csharp.ts` — adds the 9 hook entry points to the provider
  (emitScopeCaptures, interpretImport, interpretTypeBinding, four
  simple hooks, mergeBindings, arityCompatibility, resolveImportTarget).
- `scope-resolution/pipeline/registry.ts` — registers csharpScopeResolver
  alongside the Python entry.

MIGRATED_LANGUAGES stays at {Python} — the resolver sits idle until
Unit 7's parity gate confirms ≥99% fixture parity. 368/368
scope-resolution unit tests pass; tsc clean.

* feat(csharp-scope): parity Unit 1 — this/base receiver-binding synthesis

Closes 3 parity failures (51 → 48). Target bucket: Category C from the
parity plan.

Changes:
- `languages/csharp/receiver-binding.ts` (new): walks up from a
  function node to the enclosing class/struct/record/interface,
  synthesizes `@type-binding.self` captures with boundName `'this'`
  (and `'base'` when the enclosing type is a class/record with an
  explicit base_list entry). Skips static methods and interface /
  struct `base` cases. Anchors to the method's `body` block so the
  scope-extractor's positionIndex places the binding inside the
  function scope (not the enclosing class scope).
- `languages/csharp/captures.ts`: route `@scope.function` matches
  through the synth, emitting the receiver captures as separate
  matches.
- `languages/csharp/interpret.ts`: map `@type-binding.self` to
  `source: 'self'` (parity with Python).
- `languages/csharp/query.ts`: explicit patterns for `this.X()`,
  `base.X()`, and `this.X = ...` / `base.X = ...` assignment writes.
  `this` and `base` are anonymous tokens in tree-sitter-c-sharp so
  the existing `expression: (_)` pattern (named-only) didn't match.

Tests:
- 8 new unit tests for receiver-binding synthesis edge cases
  (class/struct/record/interface, static, nested, constructor,
  local function inside method).
- Parity: 48 failed | 127 passed (175) under REGISTRY_PRIMARY_CSHARP=1;
  legacy path 175/175 green.

* feat(csharp-scope): parity Unit 2a — foreach + pattern + field captures

Closes 11 parity failures (48 → 37). Partial Unit 2 progress.

Adds type-binding captures for every shape the parity suite exercises
whose resolution path is in-file:

- Typed foreach `foreach (User u in xs)` — @type-binding.annotation
  with bindingName `u` and type `User`.
- Var foreach `foreach (var u in xs)` — @type-binding.alias so the
  generic-stripper unwraps `List<User>` / `Dictionary<K,V>.Values` to
  the element type at chain-follow time. Matches Python's for-loop
  alias pattern.
- `is` pattern `if (obj is User u)` — @type-binding.annotation with
  scope narrowing simplified to function scope (matches Python's
  match-case treatment since we don't emit @scope.block).
- `switch_section > declaration_pattern` (`case User u:`) — no
  case_pattern_switch_label wrapper in tree-sitter-c-sharp.
- `recursive_pattern` (`is User { Age: 1 } u` / `case User { ... } u:`)
  — named binding via type+name fields on the pattern node.
- Field declaration `private City _city;` — @type-binding.annotation
  attached to the class scope for `this._city.X` resolution.
- Property declaration `public User Owner { get; set; }` — same.
- Assignment rebind `alias = Factory()` / `alias = new User()` —
  @type-binding.alias / @type-binding.constructor so reassignment
  propagates type info to later receiver-typed resolution.

Closed tests: foreach (3), var foreach Tier 1c (2), is-pattern (1),
switch pattern (2), recursive_pattern (3). Remaining 37 include
tests that need cross-file same-namespace visibility (field chains,
assignment chain, cross-file return-type propagation) — deferred to
Unit 5 where the IMPORTS/cross-file work lives.

74/74 scope-resolution unit tests pass; legacy path 175/175 green.

* feat(csharp-scope): parity Unit 2b — same-namespace cross-file visibility

Closes 3 parity failures (37 → 34). Adds the C#-specific implicit
import that has no syntactic counterpart: every type declared in
`namespace X` is visible to every other file also declaring
`namespace X`, without any `using` directive.

Changes:
- `scope-resolution/contract/scope-resolver.ts` — new optional hook
  `populateNamespaceSiblings(parsedFiles, indexes, { fileContents })`.
  Most languages leave it undefined; Python / TypeScript / Java need
  explicit imports so there's no analogous pass.
- `scope-resolution/pipeline/run.ts` — invoke the hook after
  `buildWorkspaceResolutionIndex` and before
  `propagateImportedReturnTypes` so the return-type pass sees
  cross-file sibling class bindings.
- `languages/csharp/namespace-siblings.ts` (new) — groups top-level
  class-like defs by namespace name (extracted from source via regex
  since `file_scoped_namespace_declaration` scope range covers only
  the declaration line, not the rest of the file). Injects sibling
  classes into each file's Module AND Namespace scope bindings with
  origin='namespace'. Local declarations shadow cross-file siblings
  via mergeBindings tier precedence.
- `languages/csharp/scope-resolver.ts` — wire the hook.

74/74 scope-resolution unit tests pass; legacy path 175/175 green;
34 parity failures remain (was 37) under REGISTRY_PRIMARY_CSHARP=1.

* feat(csharp-scope): parity Unit 2c — alias/await/return-type captures

Closes 7 parity failures (34 → 27). Adds the remaining type-binding
shapes the parity suite exercises:

- `var alias = u;` / `alias = u;` — identifier-to-identifier alias.
  The resolver's chain-follow walks alias → u → u's declared type.
- `var u = svc.GetUser();` — chained method call alias. Anchors on
  the method_access_expression's `name` field; chain-follow picks up
  GetUser's return type.
- `var u = await Factory();` / `await svc.Get();` — await propagation.
  Strips the `await_expression` wrapper; interpret layer's
  `stripGeneric` handles `Task<T>` / `ValueTask<T>` unwrapping.
- `public User GetUser() { ... }` — method return-type annotation
  via `@type-binding.return`. Required for `propagateImportedReturnTypes`
  to see the return type in later cross-file passes. Covers identifier,
  generic_name, qualified_name, and nullable_type return shapes.

74/74 scope-resolution unit tests pass; legacy path 175/175 green;
27 parity failures remain under REGISTRY_PRIMARY_CSHARP=1.

* feat(csharp-scope): parity Unit 3a — cross-namespace `using` binding

Closes 2 parity failures (27 → 25). Extends the namespace-siblings
pass to resolve `using X;` directives against known namespace
buckets: for each `using` that targets a namespace declared
somewhere in the workspace, inject that namespace's classes into
the importer's module scope with origin='namespace'.

This is the scope-resolution analog of legacy's csproj-driven
directory↔namespace mapping. Without it, `new User()` in
`Services/UserService.cs` (namespace MyApp.Services) can't see the
User class in `Models/User.cs` (namespace MyApp.Models) even with
`using MyApp.Models;` — the scope-resolver layer doesn't have
csproj metadata to translate the dotted namespace path into a
directory lookup.

Legacy 175/175 green; 25 parity failures remain.

* feat(csharp-scope): parity Unit 3b — constructor CALLS emission

Closes 3 parity failures (25 → 22). Adds constructor-form CALLS
edge emission + C# 12 primary constructor synthesis.

Changes:
- `scope-resolution/passes/free-call-fallback.ts`: when a site's
  callForm === 'constructor', look up the class def (not a callable)
  and pick its explicit Constructor def via workspaceIndex's
  memberByOwner — or fall back to the Class def itself for implicit
  constructors. Matches legacy behavior (targetLabel === 'Constructor'
  when explicit, 'Class' when implicit).
- `scope-resolution/pipeline/run.ts`: pass workspaceIndex to the
  free-call fallback.
- `languages/csharp/captures.ts`: synthesize @declaration.constructor
  for C# 12 primary constructors — `class User(string name, int age)`
  / `record Person(string First, string Last)`. The parameter_list is
  a named child of the class_declaration / record_declaration (not a
  separate constructor_declaration node). Skip the synthesis when
  the type already has an explicit constructor to avoid duplicates.
  Emits @declaration.parameter-count + required-parameter-count
  alongside.

Legacy 175/175 green; 376/376 scope-resolution unit tests pass;
22 parity failures remain.

* feat(csharp-scope): parity Unit 3c — static call + default-namespace

Closes 2 parity failures (22 → 21).

- `receiver-bound-calls.ts`: add Case 5 for class-as-receiver. When
  `Animal.Classify()` has an identifier receiver that resolves to a
  Class binding (rather than a variable with a typeBinding), look up
  the member on the class's MRO chain. Covers C#-style static calls
  and any type-qualified member access. Python doesn't hit this
  because `ClassName.method()` is syntactically identical to a free
  call there.
- `namespace-siblings.ts`: treat files with no `namespace X;`
  declaration as living in the default (empty-name) bucket, so
  types declared in no-namespace files share cross-file visibility.
  Required for fixtures without explicit namespaces (e.g. the
  method-enrichment fixture's Animal/App/Dog classes).

Legacy 175/175 green; 21 parity failures remain.

* feat(csharp-scope): parity Unit 4 — callsite arity synthesis (infra)

Synthesize @reference.arity on every invocation_expression and
object_creation_expression by counting `argument` named children of
the backing `argument_list`. Wires the capture-to-Callsite pipeline
shared extractor already consumes (`scope-extractor.ts:878`).

No parity-count movement: the remaining arity-adjacent failures
(overload disambiguation, optional-parameter dedup, variadic
resolution) need type-based argument inference or member-call dedup,
both explicitly deferred in the plan's Known Limitations section.
This commit is infrastructure — future work lands on top of it.

Legacy 175/175 green; 21 parity failures remain.

* feat(csharp-scope): parity Unit 5a — IMPORTS edge + static-using mapping

Closes 1 parity failure (21 → 20). Fixes cross-file IMPORTS edge
emission for C#:

- `languages/csharp/interpret.ts`: map `using static X.Y;` to
  `kind: 'namespace'` rather than `'wildcard'`. The File→File
  IMPORTS edge needs a non-wildcard kind to survive finalize's
  Phase 4 (wildcard-expanded edges drop to empty when the provider
  doesn't implement `expandsWildcardTo`). Unqualified static-member
  access is a deferred limitation — covered by the namespace-siblings
  cross-namespace pass for type lookups, and documented under the
  module's Known Limitations.
- `languages/csharp/import-target.ts`: progressive prefix stripping.
  `using CrossFile.Models;` in a repo laid out `Models/User.cs` (no
  `CrossFile/` directory) works because the legacy resolver consults
  csproj; the scope-resolver tries each suffix of the dotted path
  against `.cs` files. Also handles `using static NS.Type;` by
  stripping leading segments until a direct match lands.
- `test/unit/scope-resolution/csharp/csharp-imports.test.ts`: update
  the `using static` test to the new namespace-kind shape.

376/376 scope-resolution unit tests pass; legacy 175/175 green;
20 parity failures remain.

* feat(csharp-scope): parity Unit 5b — return-type module hoist + chain fallback

Closes 1 parity failure (20 → 19) and lays groundwork for Unit 6.
Based on investigation-agent findings, addresses cluster of 7
cross-file + chain tests whose return-type bindings were stuck at
Class scope and invisible to the chain-follow and propagation passes.

Changes:
- `languages/csharp/simple-hooks.ts::csharpBindingScopeFor`: when the
  declaration is a `@type-binding.return`, hoist the binding all the
  way to the Module scope. The central extractor's auto-hoist only
  promotes one level (Function → Class); for C# methods the parent
  is always a Class, so without this override the return binding
  never reaches Module where chain-follow and cross-file
  `propagateImportedReturnTypes` read from.
- `scope-resolution/passes/compound-receiver.ts`: when the
  class-scope typeBindings lookup at `objClass.typeBindings.get(
  methodName)` misses, walk up from the class scope through the
  parent chain (→ Module) for a return-type binding. Preserves the
  existing class-scope fast-path while restoring owner-chain lookup
  for languages that hoist to Module.

Python parity suite stays 204/204 green on both flag paths;
legacy C# 175/175 green; 19 C# parity failures remain.

* feat(csharp-scope): parity Unit 5c — switch-expr + reasons + ACCESSES 1.0

Closes 4 parity failures (19 → 15).

- `languages/csharp/query.ts`: add captures for `switch_expression_arm`
  with `declaration_pattern` and `recursive_pattern`. C# expression-
  switch (`obj switch { User u => ..., Repo { Name: "x" } r => ... }`)
  uses a different AST node from classic `switch_statement`'s
  `switch_section` — needed separate query patterns.
- `scope-resolution/passes/receiver-bound-calls.ts`: replace the
  self-describing `'scope-resolution: *-receiver'` reason strings
  (which fail legacy-parity consumer filters) with the legacy
  convention: `'import-resolved'` when the resolved member lives in
  a different file, `'global'` otherwise. Mirrors
  `free-call-fallback.ts`'s existing reason logic.
- `scope-resolution/passes/receiver-bound-calls.ts`: pass
  `confidence: 1.0` to `tryEmitEdge` for write/read ACCESSES edges,
  matching legacy DAG behavior (default 0.85 was legacy-CALLS).

Python parity 204/204 on both flag paths; legacy C# 175/175;
15 C# parity failures remain.

* feat(csharp-scope): parity Unit 5d — cross-file typeBinding mirror

Closes 3 parity failures (15 → 12).

`languages/csharp/namespace-siblings.ts`: extend the pass to mirror
method return-type bindings from accessible sibling files' Module
scopes into the importer's Module scope. "Accessible" =
same-namespace siblings + `using namespace X;` targets.

Without this mirror, `var u = svc.GetUser()` in App.cs couldn't
chain-follow to User even after Unit 5b's module-scope hoist:
`GetUser → User` lived on User.cs's Module scope, which isn't on
the ancestor chain of App.cs's function scope, and
`propagateImportedReturnTypes` only mirrors across explicit
ImportEdge targets (not same-namespace implicit visibility).

Closes: var-invocation return type, async/await u.Save (ambient
namespace), cross-file return-type propagation (via u.Save /
u.GetName in Program.cs).

Python parity 204/204 on both flag paths; legacy C# 175/175;
12 C# parity failures remain.

* feat(csharp-scope): parity Unit 5e — namespace-prefix bucket matching

Closes 2 parity failures (12 → 10).

`languages/csharp/namespace-siblings.ts`: when matching accessible
namespaces against class buckets, also probe every dotted prefix.
`using static CrossFile.Models.UserFactory;` parses into the
importer's accessible-namespace set as the full type path, but the
matching bucket is keyed on the containing namespace
(`CrossFile.Models`). Walking back through the dotted segments
ensures the static-using importer sees the containing namespace's
sibling files' return-type bindings.

Legacy 175/175 green; 10 C# parity failures remain.

* feat(csharp-scope): parity Unit 6a — class-like owner extension

Closes 1 parity failure (10 → 9). Extends `populateClassOwnedMembers`
to recognize Interface / Struct / Record / Enum / Trait as class-like
owners, not just Class.

The C# scope query collapses interface_declaration / struct_declaration
/ record_declaration / enum_declaration to @scope.class (they share
body-scope semantics), but the declaration-side tags produce defs of
type Interface / Struct / Record / Enum. `populateClassOwnedMembers`
previously only looked for Class-typed defs in class scopes, so
interface members (including C# 8+ default methods) never got
ownerIds — making them invisible to `findOwnedMember` via
`memberByOwner`.

With this fix, `user.Validate()` on a variable typed as `IValidator`
resolves correctly: receiver-bound-calls Case 4 finds IValidator via
findClassBindingInScope (which already accepted Interface), walks the
chain, and findOwnedMember locates Validate now that the interface
default has a proper ownerId.

Legacy C# 175/175 green; Python parity 204/204 on both flag paths;
9 C# parity failures remain.

* feat(csharp-scope): parity Unit 6b — member-call dedup + handled-site fix

Closes 1 parity failure (9 → 8). Adds the missing legacy-parity
behavior: collapse multiple member-call sites from the same caller
to the same target into one CALLS edge.

Changes:
- `scope-resolution/contract/scope-resolver.ts`: new optional
  `collapseMemberCallsByCallerTarget` flag. Default false (preserves
  the per-site invariant); C# sets it true.
- `scope-resolution/graph-bridge/edges.ts`: dedup key drops
  `line:col` when `collapseByCallerTarget` is on AND edgeType is
  `CALLS` (ACCESSES writes keep per-site granularity).
- `scope-resolution/passes/receiver-bound-calls.ts`: plumbs
  `collapse` through every `tryEmitEdge` call, and crucially marks
  `handledSites.add(siteKey)` whenever a resolved def was found —
  not only when the edge was freshly emitted. Otherwise the site
  leaked through to `emitReferencesViaLookup` which re-emitted a
  per-site edge, defeating the collapse.
- `languages/csharp/scope-resolver.ts`: opt in to the collapse.

Python parity 204/204 on both flag paths; legacy C# 175/175 green;
8 C# parity failures remain.

* feat(csharp-scope): parity Unit 6c — Dictionary.Values / .Keys unwrap

Closes 2 parity failures (8 → 6).

Dictionary<K,V>.Values in a foreach binds the element to V; .Keys
binds to K. Without this, `foreach (var user in data.Values)` where
`data: Dictionary<string, User>` couldn't propagate user's type to
User, and `user.Save()` stayed unresolved.

Changes:
- `languages/csharp/interpret.ts`: don't strip the qualifier when
  the final dotted segment is a known collection accessor
  (`Values` / `Keys`). Preserves the dotted form so downstream
  resolvers can unwrap the receiver's generic type based on the
  suffix.
- `scope-resolution/passes/compound-receiver.ts`: new
  `extractDictionaryArgs` helper splits `Dictionary<K, V>` at the
  top-level comma. In the dotted-access walk, detect trailing
  `.Values` / `.Keys` and return V/K via findClassBindingInScope
  instead of the normal class-walk (Dictionary itself isn't a
  local class def).
  - Handles nested cases: `this.data.Values` walks `this.data`
    recursively (resolving `data` as a field on `this`'s class)
    before applying the unwrap.
- `scope-resolution/passes/receiver-bound-calls.ts` Case 3b: when
  the typeRef's trailing segment is an accessor, pass the raw
  dotted path to `resolveCompoundReceiverClass` without appending
  `()` — the extra parens would misroute to the call-expression
  branch.

Python parity 204/204 on both flag paths; legacy C# 175/175 green;
6 C# parity failures remain.

* feat(csharp-scope): parity Unit 6d — using-static member injection

Closes 2 parity failures (6 → 4). `using static X.Y.Z;` now injects
every public static method of class Z into the importer's module
scope, so `Record("hi")` (without `Logger.` qualifier) resolves to
`Logger.Record` as a free call.

`languages/csharp/namespace-siblings.ts`: regex-scan each file's
source for `using static X.Y.Z;` directives. For each, look up the
class Z in the `X.Y` namespace bucket, walk its owning file's
localDefs for method/function members with `ownerId === Z.nodeId`,
and inject them as `origin: 'import'` bindings in the importer's
module-scope finalized bindings map. `findCallableBindingInScope`
then picks them up via its imported-bindings check.

Closes: variadic `Record(params string[])` + heritage arity
narrowing `WriteAudit`.

Python parity 204/204 on both flag paths; legacy C# 175/175 green;
4 C# parity failures remain (interface-dispatch pass + type-based
overload disambiguation).

* feat(csharp-scope): parity Unit 6e — overload disambig + interface dispatch + FLAG FLIP

Closes the final 4 parity failures (4 → 0). C# now runs the
registry-primary scope-resolution path by default — added to
MIGRATED_LANGUAGES.

Changes:
- `scope-resolution/scope/walkers.ts`: was already extended in
  Unit 6a to recognize Interface/Struct/Record/Enum as class-like
  owners (interface default methods get ownerIds).
- `scope-resolution/passes/receiver-bound-calls.ts`: build
  IMPLEMENTS edge index → emit secondary `interface-dispatch`
  CALLS edges to every implementor's same-named member when the
  primary receiver-typed edge targets an Interface method (closes
  heritage CreateUser CALLS-count test).
- `scope-resolution/passes/receiver-bound-calls.ts`: new
  `pickOverload` helper narrows multi-valued
  `membersByOwner.get(owner).get(name)` candidates by arity then
  argument types. Replaces the first-seen `findOwnedMember` lookup
  in Case 4 so receiver-typed overloaded calls pick the right def.
- `scope-resolution/passes/free-call-fallback.ts`: new
  `pickImplicitThisOverload` walks up to the enclosing class scope
  and applies the same arity + argument-type narrowing for free
  calls inside a class body (`Lookup("alice")` → `Lookup(string)`).
- `scope-resolution/workspace-index.ts`: new `membersByOwner`
  multi-valued index (`Map<owner, Map<name, Def[]>>`) preserves
  every overload alongside the existing first-seen `memberByOwner`.
- `scope-resolution/graph-bridge/node-lookup.ts` +
  `scope-resolution/graph-bridge/ids.ts`: include parameter-types
  suffix in the qualified lookup key for Method nodes. Legacy
  parse-phase encodes the type tag into the node id (`Method:f.cs:
  UserService.Lookup#1~int`); without this two same-arity overloads
  collapsed to one lookup entry and routed to the wrong graph node.
- `scope-resolution/contract/scope-resolver.ts`: new
  `collapseMemberCallsByCallerTarget` opt-in flag (was added in
  Unit 6b for member-call dedup; documented here).
- `gitnexus-shared/src/scope-resolution/reference-site.ts`: new
  `argumentTypes` field carrying inferred per-arg types.
- `scope-extractor.ts`: read @reference.parameter-types capture into
  `site.argumentTypes` and add it + the declaration-arity tags to
  KNOWN_SUB_TAGS so the anchor-detection picks the right anchor.
- `languages/csharp/captures.ts`: synthesize @reference.parameter-types
  by inferring arg types from literal AST nodes (integer_literal →
  'int', string_literal → 'string', constructor_expression →
  type-name, etc).
- `languages/csharp/scope-resolver.ts`: opt in to
  `collapseMemberCallsByCallerTarget`.
- `registry-primary-flag.ts`: **add CSharp to MIGRATED_LANGUAGES**.

Final state:
- C# parity: 175/175 green on flag-on AND flag-off.
- Python parity: 204/204 green on both flag paths (no regression).
- TypeScript clean.

51 → 0 failures across 18 commits on `feat/csharp-scope-resolution`.

* refactor(scope-resolution): extract language-specific accessor unwrap to provider hook

Optimizer pass: move C# Dictionary-family `.Values`/`.Keys` handling
out of the shared `compound-receiver.ts` (where it had hardcoded
regex + accessor names) into a provider-level
`unwrapCollectionAccessor` hook. The shared pass now takes an
arbitrary language-specific unwrap function; C# supplies its
Dictionary implementation in `languages/csharp/accessor-unwrap.ts`.

Related cleanup in `receiver-bound-calls.ts` Case 3b: replace the
hardcoded `tail === 'Values' || tail === 'Keys'` accessor check with
a try-dotted-walk-first / fall-back-to-call-form strategy. This
removes the last C#-specific branch in the shared pass and makes the
logic generalize cleanly to other languages that use property-style
accessors for collection views (Kotlin `.size`, future languages).

Changes:
- `scope-resolution/contract/scope-resolver.ts`: new optional
  `unwrapCollectionAccessor(receiverType, accessor) => string | undefined`
  hook. Documented as language-specific with examples.
- `scope-resolution/passes/compound-receiver.ts`: delete
  `extractDictionaryArgs`, accept `unwrapCollectionAccessor` via
  options, call it for trailing accessor segments.
- `scope-resolution/passes/receiver-bound-calls.ts`: plumb the hook
  through to `resolveCompoundReceiverClass`, remove the
  C#-hardcoded Case 3b accessor check.
- `languages/csharp/accessor-unwrap.ts` (new): C# Dictionary-family
  regex + element-type extraction.
- `languages/csharp/scope-resolver.ts`: opt in.

Audit outcome: everything else added across the 19 C# migration
commits is either correctly scoped to `languages/csharp/` (query,
captures, namespace-siblings, receiver-binding, interpret, imports)
or correctly generic in shared paths (argumentTypes field,
collapseMemberCallsByCallerTarget flag, overload narrowing via
parameterTypes, interface-dispatch via IMPLEMENTS edges, class-like
owner extension for Interface/Struct/Record/Enum, type-tagged node
IDs, module-scope return-type lookup fallback).

175/175 C# green on both flag paths; 204/204 Python green on both
flag paths; TypeScript clean.

* refactor(scope-resolution): gate module-scope typeBinding walk-up on hook

Add optional `hoistTypeBindingsToModule` to the ScopeResolver contract
and gate the Module-scope walk-up in `resolveCompoundReceiverClass` on
it. Only providers that hoist method return-type bindings to Module
scope (C#) opt in; Python and other providers no longer traverse that
fallback path.

Closes the architectural leak flagged in the production-readiness
review: the walk-up was unconditional and therefore widened Python's
code path despite existing only for C#.

No behavior change for C# (hook=true restores the prior lookup). No
behavior change for Python (hook undefined = walk-up skipped, matching
pre-PR behavior).

Verified:
  - npx tsc --noEmit           clean
  - C# unit suite              74/74 passing
  - C# + Python integration    388/388 passing

* refactor(csharp-scope): remove as-unknown-as double casts in scope-resolver

Tighten three type boundaries that were previously papered over with
`as unknown as` casts:

  * `CsharpResolveContext.allFilePaths`: `Set<string>` → `ReadonlySet<string>`.
    The orchestrator only hands out a read-only view; drop the widening
    cast at the resolver-adapter site.
  * `resolveCsharpImportTarget`: call passes the narrow context directly.
    `WorkspaceIndex` is `unknown` in the shared contract, so the
    `as unknown as WorkspaceIndex` cast was gratuitous — structural
    assignability covers it.
  * `csharpMergeBindings`: drop unused `_scope: Scope` parameter. The
    implementation never read it; the cast chain in `scope-resolver.ts`
    existed only to satisfy an unused slot. LanguageProvider.mergeBindings
    now wraps with a tiny arrow adapter; ScopeResolver.mergeBindings
    passes through directly.

No runtime behavior change. `grep 'as unknown as' csharp/scope-resolver.ts`
returns zero matches.

Verified:
  - npx tsc --noEmit           clean
  - C# unit + integration      462/462 passing (incl. Python integration)

* test(csharp-scope): integration fixtures for Units 6c/6d/6e runtime behavior

Close the integration-coverage gap flagged in the production-readiness
review. Units 6c (collection-accessor unwrap), 6d (using-static member
injection), and 6e (overload disambig + interface dispatch) previously
had only hook-level unit tests; the end-to-end wiring was exercised
only by the parity harness.

Three minimal fixtures + four new it() blocks:

  * csharp-collection-accessor — RenderAll iterates
    Dictionary<string, Widget>.Values and calls .Render(); asserts the
    CALLS edge lands on Widget.Render.
  * csharp-using-static — `using static Helpers.MathUtils;` makes
    Square(int) a free-callable in the consumer; asserts the CALLS
    edge lands on MathUtils.Square.
  * csharp-overload-interface — three assertions:
      1. Run → Log binds to the 2-arg overload only (arity narrowing);
         verified via target Method node's parameterTypes.length === 2.
      2. Run → Greet emits one primary edge to IGreeter.Greet plus two
         reason='interface-dispatch' siblings to En/FrGreeter.Greet.
      3. Interface-dispatch fan-out excludes the primary target.

Verified:
  - csharp integration        189/189 passing

* docs(scope-resolution): de-c#-ify optional-hook doc-comments on contract

Rewrite the doc-comments on four optional hooks so they describe the
behavior and when a provider would enable it, rather than naming C#
as the sole consumer. Hook names were already generic — only the
comments had baked in one-language framing, which risked discouraging
future reuse.

Affected hooks:
  * unwrapCollectionAccessor
  * collapseMemberCallsByCallerTarget
  * populateNamespaceSiblings
  * hoistTypeBindingsToModule

Language-specific rationale stays where it belongs — next to the hook
assignment in `languages/csharp/scope-resolver.ts`. Zero-match grep for
`C#|csharp|CSharp` in the contract file confirms the separation.

No code change.

* docs(csharp-scope): justify regex-based namespace-sibling detection

Record why `namespace-siblings.ts` uses regex over AST walks and
enumerate the known misses so the next reader has ground to stand on:

  * `global using static X.Y;` — no plain `using static` token.
  * Aliased `using static X = Y.Z;` — `=` breaks the pattern.
  * Attributed namespace declarations between `]` and `{`.
  * Multi-namespace files — first-wins attribution.
  * Preprocessor-gated namespace declarations — textual branch only.

Rationale: the pass is file-path-driven and the tree-sitter tree isn't
available at its call site (the orchestrator feeds raw fileContents);
re-parsing to count namespaces would cost more than the regex walk.
Refactor to AST-driven detection is deferred to a separate PR.

Mirrored the known-miss list into `csharp/index.ts`'s limitations
ledger so the operator-visible surface and the in-code justification
stay in sync.

No code change.

* refactor(csharp-scope): AST-driven namespace detection with treeCache reuse

Replace regex-over-source-content with tree-sitter AST walks in
namespace-siblings.ts; thread the orchestrator's treeCache through
the populateNamespaceSiblings hook so the pass reuses the same parse
trees `extractParsedFile` already consumed (single-source-of-truth
for the AST — no double-parse).

Behavior gains (no longer "known misses"):
  * `global using static X.Y;` is now detected.
  * Aliased `using static X = Y.Z;` is now detected.
  * Attributed namespace declarations (`[attr] namespace X`) parse
    correctly because tree-sitter sees them as one node.
  * Preprocessor-gated namespace declarations parse via the grammar.

Contract change (additive, optional):
  * `populateNamespaceSiblings` ctx now carries an optional
    `treeCache?: { get(filePath): unknown }`. Existing providers that
    don't set it on `RunScopeResolutionInput` see undefined, and the
    hook falls back to a fresh parse (current behavior preserved on
    cache miss).

Limitation ledger updated in csharp/index.ts: the AST-based detection
removes 4 of the 5 prior known misses; only "first-wins multi-namespace
file attribution" remains.

Verified:
  - npx tsc --noEmit                         clean
  - C# + Python integration                  393/393 passing

* refactor(python-scope): remove as-unknown-as casts in scope-resolver (mirrors Unit 2)

Replay the C# scope-resolver cleanup on the Python side so both
providers share a single clean pattern:

  * Drop `ws as unknown as WorkspaceIndex` — `WorkspaceIndex` is
    `unknown` in the shared contract, so the narrow context assigns
    structurally without a cast.
  * Drop `{ id: scopeId } as unknown as Scope` — `pythonMergeBindings`
    never read the scope (the parameter was `_scope`), so the stub
    was a type-only ghost. Signature is now `(bindings)` and the
    LanguageProvider slot wraps with an arrow adapter.
  * Drop `allFilePaths as Set<string>` — the orchestrator hands a
    `ReadonlySet<string>`; we copy it into a `Set` at the resolver
    adapter so the legacy downstream `resolvePythonImportInternal`
    chain (typed for mutable `Set<string>`) keeps working. The copy
    is O(N) once per import, trivial cost.

Left intact on purpose: the `(callsite, def) → (def, callsite)`
arrow wrapper on `arityCompatibility`. That's a documented shape
difference between `LanguageProvider.arityCompatibility(def, callsite)`
and `ScopeResolver.arityCompatibility(callsite, def)`; both providers
(Python + C#) carry the same wrapper. Reconciling is a separate
refactor across both contracts.

No runtime behavior change.

Verified:
  - npx tsc --noEmit                              clean
  - Python + C# unit + integration suites         529/529 passing

* docs(scope-resolution): document I1-I8 invariants, source-of-truth, and same-graph guarantee

Promote contract knowledge that was implicit in code into the canonical docs
so future migrations and the next reviewer don't have to reverse-engineer it.

contract/scope-resolver.ts:
  * Migration cookbook lists every optional hook (was: only the two
    booleans), with one-line guidance per hook including when to enable
    `hoistTypeBindingsToModule`.
  * Contract Invariants I1-I7 are now spelled out in full (was: only
    I1/I3/I5 summarized with a pointer to a plan file). Added new I8
    "post-finalize hooks may mutate Scope.typeBindings and indexes.bindings;
    consumers must not freeze or snapshot before all post-finalize hooks
    have run".
  * New "Semantic-model source of truth" section: ParsedFile is the
    single semantic model; passes that need AST-level facts must reuse
    the orchestrator's treeCache rather than re-parse.
  * New "Same-graph guarantee" section: legacy DAG and scope-resolution
    emit indistinguishable edges (node identity, edge vocabulary,
    confidence). CI parity workflow enforces this.

gitnexus-shared/src/scope-resolution/parsed-file.ts:
  * Added "Source-of-truth invariant" pointer paragraph.

ARCHITECTURE.md (Coexistence section):
  * Updated migrated-language list (Python + C#).
  * Added "Same-graph guarantee" subsection.
  * Added "Semantic-model source of truth" subsection.
  * Filled in the ScopeResolver hook table with the five optional hooks
    that landed in this branch (unwrapCollectionAccessor,
    collapseMemberCallsByCallerTarget, populateNamespaceSiblings,
    hoistTypeBindingsToModule, fieldFallbackOnMethodLookup).
  * Added C# rows to the code-references table.

Verified:
  - npx tsc --noEmit                                 clean
  - C# + Python integration                          393/393 passing

* refactor(scope-resolution): consume SemanticModel as single authoritative store

Unify scope-resolution and legacy parse into one symbol index per the
industry pattern (Roslyn / tsc / rust-analyzer). Scope-resolution
passes now consume `SemanticModel.methods` / `SemanticModel.fields` /
`SemanticModel.symbols` for all symbol-keyed lookups. The legacy DAG
already read from these; the drift — two parallel owner-keyed indexes
populated by two writers with divergent ownerId semantics — is closed.

Changes:

  * `MethodRegistry.lookupAllByOwner(owner, name)`: new API returning
    every overload without arity narrowing. Powers `findOwnedMember` /
    `pickOverload`.

  * `pipeline/run.ts` reconciliation pass: after
    `provider.populateOwners(parsed)`, iterate `parsed.localDefs[i]`
    and register methods/fields into the SemanticModel under the
    corrected ownerId. Idempotent — skips defs already present under
    `(ownerId, simple)` by nodeId, so unmigrated languages whose
    legacy extractor already set ownerId (C#) don't double-register.
    Closes the Python gap where class-body methods were invisible to
    `MethodRegistry` because the legacy Python method extractor
    couldn't resolve `enclosingClassId` at parse time.

  * `WorkspaceResolutionIndex` slimmed to Scope-valued maps only
    (`classScopeByDefId`, `moduleScopeByFile`). Dropped `memberByOwner`,
    `membersByOwner`, `defsByFileAndName`, `callablesBySimpleName` —
    all symbol-keyed duplicates of SemanticModel indexes.

  * Walker helpers now consume SemanticModel:
      - `findOwnedMember(owner, name, model)` → methods then fields
        fallback (ACCESSES writes target Property/Variable defs too).
      - `findExportedDefByName` fallback walks every Module scope's
        `origin === 'local'` bindings via `index.moduleScopeByFile`
        (preserves the module-export-visibility filter that
        SymbolTable.fileIndex can't cheaply encode).
      - `findExportedDef` reads `moduleScope.bindings` directly.

  * `pickOverload` in receiver-bound-calls.ts falls back to
    `model.fields.lookupFieldByOwner` when method lookup returns empty,
    fixing ACCESSES write edges that receive a Property target.

  * `phase.ts` threads `resolutionContext.model` into
    `RunScopeResolutionInput`.

Boundary rule, enforced by file placement:
  - symbol-indexed lookups (key = nodeId / name / filePath) →
    `SemanticModel`
  - Scope-valued lookups (value = `Scope`) →
    `WorkspaceResolutionIndex`

Research synthesized from web-researcher + Explore + best-practices +
system-architect agents; canonical references: Roslyn Overview,
rust-analyzer architecture, stack-graphs paper.

Verified:
  - npx tsc --noEmit                               clean
  - C# + Python integration                        393/393 passing

* docs(scope-resolution): refresh comments after dropping duplicated indexes

Replace references to the now-deleted `memberByOwner` /
`callablesBySimpleName` index fields with comments that describe the
actual lookup path (`SemanticModel` registries + scope-tied module
bindings). Pure doc cleanup; no behavior change.

* feat(scope-resolution): extract reconciliation pass + add parity validator

Extract the SemanticModel reconciliation pass (previously inline in
`pipeline/run.ts`) into a dedicated module with:

  * `reconcileOwnership(parsedFiles, model)` — pure function returning
    stats (methodsRegistered / fieldsRegistered / skippedAlreadyPresent).
    Idempotent; safe to re-run.
  * `validateOwnershipParity(parsedFiles, model, onWarn)` — dev-mode
    runtime validator for Contract Invariant I9. Walks every def with
    an `ownerId` and asserts it is reachable via
    `model.methods.lookupAllByOwner` or `model.fields.lookupFieldByOwner`.
    Soft-fails via `onWarn`; never throws.

Validator is gated on both `NODE_ENV !== 'production'` and
`VALIDATE_SEMANTIC_MODEL !== '0'` so production incurs zero cost but
development surfaces any drift between `parsed.localDefs` ownership and
the registries.

12 new unit tests cover:
  * happy path: method, property, Variable registration
  * edge case: defs without ownerId are skipped
  * idempotency: second call is a no-op
  * coexistence: defs the legacy extractor already registered (via
    `model.symbols.add`) are skipped on reconcile
  * overloads: multiple methods under the same (owner, name)
  * validator: no warnings after reconciliation
  * validator: warns on drift
  * validator: no-op under NODE_ENV=production
  * validator: no-op when VALIDATE_SEMANTIC_MODEL=0
  * validator: warns on missing Property same as missing Method

Verified:
  - npx tsc --noEmit                               clean
  - reconcile-ownership unit tests                 12/12 passing
  - C# + Python integration                        393/393 passing

* refactor(scope-resolution): narrow handles + tighten required params

Two small hygiene fixes that fell out of the unified-model work:

  * Introduce `readonlyModel: SemanticModel` in `runScopeResolution`
    immediately after reconciliation so the write/read phase boundary
    is explicit at the code level. Downstream passes (receiver-bound,
    free-call) receive the narrowed `SemanticModel` rather than the
    `MutableSemanticModel` that only the reconciliation pass needs.
    The type system now rejects accidental writes in the read phase.

  * Make `emitFreeCallFallback`'s `workspaceIndex` parameter required.
    It's now always passed (every caller threads it through), and the
    `workspaceIndex?` guard was dead code. Also drops the `| undefined`
    branch from `pickConstructorOrClass` which no caller can hit.

No behavior change.

* docs(semantic-model): document unified single-source-of-truth invariant (I9)

Add Contract Invariant I9 to the ScopeResolver contract and write the
single-source-of-truth + write/read phase contract into both the
SemanticModel file-head and ARCHITECTURE.md.

Three landing points so the rule is reachable from every entry:

  * contract/scope-resolver.ts — new I9 entry in the Contract
    Invariants list: scope-resolution passes consult SemanticModel
    exclusively for symbol-keyed lookups; WorkspaceResolutionIndex is
    reserved for Scope-valued maps. Documents the two-phase write
    (legacy parse + reconcileOwnership) and the narrowed-handle read
    posture. Calls out the reconciliation shim as transitional.

  * model/semantic-model.ts — new "Single-source-of-truth invariant"
    and "Write / read phase contract" sections in the file-head.
    Three ordered write phases (parse → reconcile → attachScopeIndexes),
    then frozen for readers.

  * ARCHITECTURE.md § "Semantic-model source of truth" — expanded
    subsection covering both invariants (ParsedFile = AST truth,
    SemanticModel = symbol truth), the write/read phase diagram, and
    the reconciliation-shim rationale.

No code change.

* test(scope-resolution): rewrite workspace-index test for slimmed index

The test file previously asserted on \`defsByFileAndName\`,
\`callablesBySimpleName\`, and \`memberByOwner\` — fields removed when
symbol-keyed lookups moved to \`SemanticModel\`. Rewrite so the same
invariants are asserted via the authoritative consumers:

  * New WorkspaceResolutionIndex shape test (scope-only maps).
  * \`findExportedDef\` module-export visibility tests:
    - keeps top-level class and function defs.
    - excludes class-body Variable defs (MAX_USERS = 100).
    - excludes class methods from module-export lookup.
  * \`findExportedDefByName\` fallback excludes class methods when a
    same-named module function exists.
  * \`findOwnedMember\` via the reconciled SemanticModel finds Python
    class methods after populateOwners + reconcileOwnership.

Total assertions preserved: every invariant from the old test file is
still pinned; the assertion surface shifted from the index shape to
the walker helpers.

Verified:
  - workspace-index.test.ts                        8/8 passing

* fix(tests): update registry-primary-flag test for C# migration

The "returns exactly the flipped languages" case expected `enabled.size === 1`
after toggling Python off and Go on. After the C# migration lands C# in
MIGRATED_LANGUAGES, C# is default-on too — so the size is now 2 (Go + C#)
unless C# is also opted out.

Turn off C# alongside Python in the test setup. Added a comment noting
that future migrations must add their REGISTRY_PRIMARY_<LANG>='false'
line here.

* refactor(scope-resolution): address PR #1019 review findings

Resolves all 5 findings from the automated review on
feat/csharp-scope-resolution. Shared ingestion code stays
language-agnostic; C# (and every class-like language) benefits.

F1 [high] Broaden class-like predicate
  Hoist `isClassLike` in `scope/walkers.ts` to an exported top-level
  helper covering Class | Interface | Struct | Record | Enum | Trait.
  Use it in `findClassBindingInScope`, `findEnclosingClassDef`, and
  `buildWorkspaceResolutionIndex` so C# records, structs, interfaces,
  and enums participate in scope chains and receiver binding the same
  way Python classes do.

F2 [medium] Remove stale comment in csharp simple-hooks
  `csharpReceiverBinding`'s doc claimed this/base synthesis was
  "planned for a follow-up"; synthesis has been implemented in
  receiver-binding.ts since the migration landed. Rewrite the doc to
  describe the actual behavior (non-null TypeRef on instance-method
  bodies, null on static/free functions).

F3 [medium] O(1) reverse lookup for classScopeId -> classDefId
  Add `classScopeIdToDefId: ReadonlyMap<ScopeId, string>` to
  `WorkspaceResolutionIndex`, populated as the inverse of
  `classScopeByDefId`. Replace the O(C) linear scan in
  `pickImplicitThisOverload` (free-call-fallback.ts) with an O(1)
  `Map.get` — turns per-site reverse resolution from linear in class
  count to constant time for every free call.

F4 [low] Extract narrowOverloadCandidates shared utility
  New `passes/overload-narrowing.ts` centralizes the arity + argument-
  type narrowing previously duplicated across `pickOverload`
  (receiver-bound-calls.ts) and `pickImplicitThisOverload`
  (free-call-fallback.ts). Both callsites now share identical
  narrowing semantics; variadic `params T` handling is preserved.
  Return type is `readonly SymbolDefinition[]` with no defensive
  spreads (allocations saved on the hot path).

F5 [low] Merge unreachable Case 5 into Case 2
  `Case 5` in `receiver-bound-calls.ts` was dead code — `Case 2`
  pre-empted it for every static/class-name receiver. Delete Case 5
  and lift its kind-aware read/write ACCESSES reason/confidence logic
  into Case 2 so static-style member access (e.g. `Interface.Member`,
  `TypeName.StaticMember`) gets the correct edge metadata.

Tests
  - New unit tests for `narrowOverloadCandidates` covering empty
    input, arity filtering, variadic params, type narrowing, and
    fallback semantics.
  - New unit tests for `classScopeIdToDefId` verifying inverse
    invariant and empty index behavior.
  - New C# integration fixtures and tests:
      * csharp-record-base — record inheritance + `base.Save()`
      * csharp-struct-overloads — struct with implicit-this overload
        narrowing (pinned exact edge count under registry-primary)
      * csharp-interface-receiver-static — interface-qualified static-
        style call exercises the merged Case 2.
  - Full runs green:
      * scope-resolution unit: 406/406
      * csharp integration (registry-primary): 197/197
      * csharp integration (legacy DAG): 197/197
      * python integration (regression guard): 204/204

Chore
  - Add `.context/` to root `.gitignore` to prevent agent scratch
    files from being committed.

Made-with: Cursor

* test(csharp-scope-resolution): address adversarial review follow-ups on PR #1019

Applies the three actionable follow-ups from the post-commit adversarial
review of 5a1bce7f against DoD.md. No runtime code changes.

- [medium] Strengthen bounds-only assertion in the struct-overloads
  suite: `methods.length` is now pinned to `toBe(2)` and the arity list
  to `toEqual([1, 2])`. Fixture `csharp-struct-overloads/src/Calc.cs`
  declares exactly two `Add` methods, so a regression that adds, drops,
  or merges an overload will now fail the test instead of silently
  passing a `>= 2` gate.

- [low] Pin the merged Case 2 kind-aware branch (receiver-bound-calls.ts
  lines 257-289) with a dedicated fixture and three new assertions:
  `csharp-class-static-field-access/src/Counters.cs` exercises
  `ClassName.Field = value` where the receiver resolves via
  `findClassBindingInScope` (no typeBinding on `Counters`). The test
  verifies (a) two distinct ACCESSES writes are emitted from a single
  method (per-site dedup from graph-bridge/edges.ts:80-87),
  (b) `reason === 'write'`, (c) `confidence === 1.0`, and (d) no
  spurious CALLS edges are produced for the same sites. This is the
  semantic upgrade lifted from the deleted Case 5; without a pinning
  test a future revert of the kind-aware branch would silently drop
  back to `import-resolved`/`global` at 0.85 for the same sites.
  Read-side coverage is intentionally not asserted because the C#
  tree-sitter query currently emits only `write.member` captures
  (languages/csharp/query.ts:485-501) — a read counterpart would have
  no reference site today and would give a false sense of coverage.

- [info] Left the `?? overloads[0]` fallback in place at
  receiver-bound-calls.ts:450 unchanged. With the package's current
  tsconfig (strict: false, no noUncheckedIndexedAccess) both the
  defensive fallback and a `candidates[0]!` assertion type-check
  identically, so the finding has no production-readiness impact.
  Keeping the fallback minimizes churn.

Validation (local, Windows PowerShell):
- `npx prettier --check test/integration/resolvers/csharp.test.ts` -> clean
- `npx tsc --noEmit` -> 0 errors
- `REGISTRY_PRIMARY_CSHARP=1 npx vitest run test/integration/resolvers/csharp.test.ts` -> 200/200
- `REGISTRY_PRIMARY_CSHARP=0 npx vitest run test/integration/resolvers/csharp.test.ts` -> 200/200
- `npx vitest run test/integration/resolvers/python.test.ts` -> 204/204
- `npm test` (full gitnexus suite) -> 6967 passed, 6 pre-existing failures
  (4x Swift overload/dedup, 1x Swift method-extraction unit, 1x Swift
  type-env unit, 1x LadybugDB lockfile on Windows). All six reproduce on
  5a1bce7f with these follow-up changes stashed, confirming they are
  environment/baseline failures unrelated to this work. Swift is not in
  MIGRATED_LANGUAGES so the merged Case 2 path cannot affect it.

Refs: PR #1019
Made-with: Cursor

* refactor(scope-resolution): address full-PR review findings on PR #1019

Resolves the two remaining findings from the code-review-swarm full-PR
sweep (verdict: production-ready with minor follow-ups).

[low] Complete the csharp/index.ts module-layout JSDoc.

`languages/csharp/index.ts` is the discovery surface for the C# scope-
resolution module decomposition (per AGENTS.md). The "Module layout"
list silently omitted three load-bearing modules — `accessor-unwrap.ts`
(`.Values`/`.Keys` receiver-type unwrap), `namespace-siblings.ts`
(AST-driven cross-file implicit-namespace visibility), and
`receiver-binding.ts` (`this`/`base` type-binding synthesis). Extended
the JSDoc list so the "single-concern" decomposition story is honest
and the next contributor can locate the right file without grep.
No behavior change.

[info] Replace the non-standard `'scope-resolution: super-receiver'`
      edge reason with the canonical `'global'` tier.

`passes/receiver-bound-calls.ts` emitted a non-canonical reason string
for the super/base branch, which falls outside the vocabulary declared
in ARCHITECTURE.md § Scope-Resolution Pipeline (`'import-resolved' |
'global' | 'local-call' | 'same-file' | 'interface-dispatch' | 'read'
| 'write'`). Super/base calls resolve through the MRO chain rather
than through import directives, so the correct canonical tier is
`'global'` (same classification the legacy DAG's `toResolveResult`
applies to non-same-file, non-import-scoped resolutions).

Locked the contract with `rel.reason === 'global'` assertions on the
existing `csharp-super-resolution` and `csharp-generic-parent-
resolution` suites, both of which go through the super-branch MRO
path. The `csharp-record-base` suite intentionally does not pin a
reason (records don't currently emit EXTENDS edges, so the MRO lookup
misses and the edge is produced by the reference-index fallback
instead of the super-branch). A code comment flags the pre-existing
Python-legacy asymmetry (Python legacy tier classifier marks
`super()` as `'import-resolved'` because the ancestor arrives via an
`import` statement); closing that gap requires realigning the legacy
tier classifier and is tracked separately.

Validation:
- `npx tsc --noEmit` passes.
- `npx prettier --check` clean on all four touched files.
- `test/integration/resolvers/csharp.test.ts` — 200/200 under both
  `REGISTRY_PRIMARY_CSHARP=0` (legacy DAG) and `REGISTRY_PRIMARY_CSHARP=1`
  (registry-primary), preserving same-graph parity on the super branch.
- `test/integration/resolvers/python.test.ts` — 204/204 under both
  `REGISTRY_PRIMARY_PYTHON=0` and `=1`.
- `test/unit/scope-resolution/` — 406/406 passing.

Unstaged: `gitnexus/package-lock.json` (drift from `npm install` run
to resolve the pre-existing missing `jsonc-parser` dependency — not
part of this change).

Made-with: Cursor

* test(ci): raise integration-test timeouts so slow Windows runners stop flaking

The `windows-latest` CI runner for this branch was consistently failing
two integration suites in ways that had nothing to do with the PR's
scope-resolution changes:

  * `cli-e2e.test.ts` — `analyze command runs pipeline on mini-repo`
    hit the default 30 s vitest test timeout, which raced the test's
    own 30 s subprocess timeout and prevented the existing
    `if (result.status === null) return;` slow-CI tolerance from ever
    firing. That single timeout then cascaded into the downstream
    `cypher`/`query`/`impact` tests (which exited non-zero because the
    mini-repo was never indexed) and the `EPIPE handling` test.
  * `skills-e2e.test.ts` — `beforeAll` hooks run a full
    `runSkillsCli(tmpDir)` subprocess that analyzes a fixture repo and
    generates skills. 50 s was enough on Linux/macOS but not on slow
    Windows CPUs, producing "Hook timed out in 50000ms" errors and
    cascading test failures across every language describe block.

Fix:
  * Bump the `analyze` test's vitest test-level timeout to 60 s so it
    exceeds the 30 s subprocess timeout and the slow-CI tolerance can
    actually activate.
  * Bump all 12 `runSkillsCli`-driven `beforeAll` hooks from 50 s to
    120 s.

No production-code behavior changes. No change to what the tests
assert — only the per-test/hook wall-clock budget.

Made-with: Cursor
2026-04-23 12:38:13 +01:00

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Architecture — GitNexus

Monorepo: CLI/MCP (gitnexus/) + browser UI (gitnexus-web/).

Repository layout

Path Role
gitnexus/ npm package gitnexus: CLI, MCP server (stdio), HTTP API, ingestion pipeline, LadybugDB graph, embeddings.
gitnexus-web/ Vite + React thin client: graph explorer + AI chat. All queries via gitnexus serve HTTP API.
gitnexus-shared/ Shared TypeScript types and constants (consumed by CLI and Web).
.claude/, gitnexus-claude-plugin/, gitnexus-cursor-integration/ Agent skills and plugin metadata.
eval/ Evaluation harnesses for benchmarking tool usage.
.github/ CI workflows + composite actions (setup-gitnexus/, setup-gitnexus-web/).

End-to-end flow: index → graph → tools

  1. Ingestionanalyze.tsrunFullAnalysis (run-analyze.ts) → runPipelineFromRepo (pipeline.ts). DAG of 12 phases builds a KnowledgeGraph in memory, then loads into LadybugDB under .gitnexus/. Repo registered in ~/.gitnexus/registry.json for MCP discovery.

  2. Persistencerepo-manager.ts (paths, registry, KuzuDB cleanup). lbug-adapter.ts (graph load, queries, embedding batches).

  3. Query layer — three interfaces to the same backend:

    • MCP (stdio): mcp.tsLocalBackend → tools (tools.ts) + resources (resources.ts)
    • HTTP bridge: serve.ts → Express (api.ts, mcp-http.ts) for web UI
    • CLI direct: gitnexus query|context|impact|cypher in tool.ts
  4. Stalenessstaleness.ts compares indexed lastCommit to HEAD, surfaces hints.

MCP tools

Tool Purpose
list_repos Discover indexed repos
query Hybrid BM25 + vector search over the graph
cypher Ad hoc Cypher against the schema
context Callers, callees, processes for one symbol
impact Blast radius (upstream/downstream) with risk summary
detect_changes Map git diffs to affected symbols and processes
rename Graph-assisted multi-file rename with dry_run preview
api_impact Pre-change impact report for an API route handler
route_map API route → handler → consumer mappings
tool_map MCP/RPC tool definitions and handlers
shape_check Response shape vs consumer property access mismatches
group_list List repo groups or details for one group
group_sync Rebuild group Contract Registry (contracts.json) and bridge graph

query, context, and impact are group-aware: pass repo: "@<groupName>" (or "@<groupName>/<memberPath>" to scope to one member) plus optional service: "<monorepo/path>". Group-mode query merges per-repo results via Reciprocal Rank Fusion; group-mode impact runs the local walk in the chosen member and fans out across boundaries via the Contract Bridge (gitnexus/src/core/group/cross-impact.ts). The previously-planned group_query, group_context, group_impact, group_contracts, group_status MCP tools are intentionally not introduced — group-level state is exposed via resources instead:

Resource URI Purpose
gitnexus://group/{name}/contracts Contract Registry (provider/consumer rows + cross-links)
gitnexus://group/{name}/status Per-member index + Contract Registry staleness

Where to change what

Concern Start in
CLI commands/flags src/cli/ (index.ts, per-command modules)
Parsing/graph construction src/core/ingestion/pipeline-phases/ + pipeline.ts
Graph schema/DB src/core/lbug/ (schema.ts, lbug-adapter.ts)
MCP tools/resources src/mcp/server.ts, tools.ts, resources.ts
Cross-repo groups (sync, contracts, @<group> routing) src/core/group/ (service.ts, cross-impact.ts, sync.ts, bridge-db.ts)
Search ranking src/core/search/ (BM25, hybrid fusion)
Embeddings src/core/embeddings/ + src/core/run-analyze.ts
Wiki generation src/core/wiki/
Language support src/core/ingestion/languages/ + tree-sitter-queries.ts + gitnexus-shared/src/languages.ts
Import resolution src/core/ingestion/import-processor.ts + import-resolvers/configs/ + model/resolution-context.ts
Call resolution/MRO src/core/ingestion/call-processor.ts + model/resolve.ts
Type extraction src/core/ingestion/type-extractors/
Worker pool src/core/ingestion/workers/
Web UI gitnexus-web/src/
CI .github/workflows/*.yml, .github/actions/

Paths above are relative to gitnexus/ unless they start with gitnexus-web/ or .github/.


Pipeline Phase DAG

12 phases defined in gitnexus/src/core/ingestion/pipeline-phases/, each with explicit deps and typed output.

scan → structure → [markdown, cobol] → parse → [routes, tools, orm]
  → crossFile → mro → communities → processes
Phase File Deps Output
scan scan.ts (root) File paths + sizes
structure structure.ts scan File/Folder nodes, CONTAINS edges, allPathSet
markdown markdown.ts structure Section nodes, cross-link edges from .md/.mdx
cobol cobol.ts structure COBOL program/paragraph/section nodes (regex, no tree-sitter)
parse parse.ts + parse-impl.ts structure, markdown, cobol Symbol nodes, IMPORTS/CALLS/EXTENDS edges, extracted routes/tools/ORM queries
routes routes.ts parse Route nodes + HANDLES_ROUTE edges (Next.js, Expo, PHP, decorators)
tools tools.ts parse Tool nodes + HANDLES_TOOL edges
orm orm.ts parse QUERIES edges (Prisma, Supabase)
crossFile cross-file.ts + cross-file-impl.ts parse, routes, tools, orm Cross-file type propagation in topological import order
mro mro.ts crossFile, structure METHOD_OVERRIDES + METHOD_IMPLEMENTS edges
communities communities.ts mro, structure Community nodes + MEMBER_OF edges (Leiden algorithm)
processes processes.ts communities, routes, tools, structure Process nodes + STEP_IN_PROCESS edges

Non-phase files in the same directory: parse-impl.ts, cross-file-impl.ts (implementation), wildcard-synthesis.ts (whole-module import expansion), orm-extraction.ts (sequential ORM fallback), types.ts, runner.ts, index.ts.

DAG runner

runner.ts — static phase graph, no plugins, compile-time type safety.

  1. Validation — Kahn's topological sort. Rejects on: duplicate names, missing deps, cycles (DFS traces the concrete cycle path, e.g., A -> B -> C -> A, plus count of transitively blocked dependents).

  2. Execution — sequential in topological order. Each phase receives:

    • ctx: PipelineContext — shared mutable KnowledgeGraph, repoPath, progress callback, options
    • deps: ReadonlyMap<string, PhaseResult>declared deps only (runner filters the results map to prevent hidden coupling)
  3. Error handling — wraps phase errors with the phase name, emits terminal error progress event, swallows progress handler errors to preserve the original cause.

  4. Timing — per-phase durationMs in PhaseResult, dev-mode console logging.

Design patterns:

  • Single graph accumulator — all phases mutate the same KnowledgeGraph in ctx; the graph is the primary output.
  • Typed phase accessgetPhaseOutput<T>(deps, 'name') for type-safe upstream results.
  • Binding accumulator lifecycle — created in parse, disposed by crossFile (in finally). No other phase should take ownership.
  • Skippable phasesskipGraphPhases omits MRO/communities/processes (faster tests). skipWorkers forces sequential parsing.

How to add a new phase

  1. Create pipeline-phases/my-phase.ts with a PipelinePhase<MyOutput> (name, deps, execute)
  2. Export from pipeline-phases/index.ts
  3. Add to buildPhaseList() in pipeline.ts
import type { PipelinePhase, PhaseResult } from './types.js';
import { getPhaseOutput } from './types.js';
import type { ParseOutput } from './parse.js';

export interface MyPhaseOutput { /* ... */ }

export const myPhase: PipelinePhase<MyPhaseOutput> = {
  name: 'myPhase',
  deps: ['parse'],
  async execute(ctx, deps) {
    const { allPaths } = getPhaseOutput<ParseOutput>(deps, 'parse');
    // ... write to ctx.graph ...
    return { /* typed output */ };
  },
};

Call-Resolution DAG

Typed 6-stage pipeline in call-processor.ts (inside the parse phase) that resolves method/function calls and emits CALLS edges. Language behavior plugs in at two LanguageProvider hook points (stages 34); shared code names no languages. Scope: call resolution only — import resolution, type extraction, heritage, and symbol-table population live in other phases.

Stages

extract-call ──▶ classify-form ──▶ infer-receiver ──▶ select-dispatch ──▶ resolve-target ──▶ emit-edge
     (1)              (2)            (3)  [hook]       (4)  [hook]         (5)                 (6)
Stage Produces Location
extract-call ExtractedCallSite (name, form, receiver, argCount) call-extractors/ (per-language); runs in worker
classify-form callForm (free/member/constructor) + arity call-analysis.tsinferCallForm; shared, runs in worker
infer-receiver ReceiverEnriched (receiver type finalized) call-processor.ts; shared default chain, then inferImplicitReceiver hook
select-dispatch DispatchDecision (primary, fallback, ancestryView) selectDispatch hook, falls back to shared default
resolve-target TieredCandidates model/resolve.tslookupMethodByOwnerWithMRO (MRO walk)
emit-edge CALLS edge in graph call-processor.ts; writes edge with confidence tier

Provider hooks

Both hooks are optional on LanguageProvider. Ruby is the only current implementer.

inferImplicitReceiver — called after shared infer-receiver defaults. Returns ImplicitReceiverOverride | null.

Inputs calledName, callForm, receiverName, receiverTypeName, callNode (AST), filePath
Non-null fields callForm, receiverName, receiverTypeName (required); receiverSource: 'implicit-self' (fixed); hint? (opaque, passed to selectDispatch)
Null Keep existing ReceiverEnriched state

selectDispatch — called after infer-receiver (including hook). Returns DispatchDecision | null; null uses shared default (constructor → primary:'constructor'; typed receiver → primary:'owner-scoped'; else → primary:'free').

Inputs calledName, callForm, receiverName, receiverTypeName, receiverSource, hint
Non-null fields primary: 'owner-scoped' | 'free' | 'constructor'; fallback?: 'free-arity-narrowed'; ancestryView?: 'instance' | 'singleton'; hint?

DispatchDecision field semantics:

  • primary: 'owner-scoped' — MRO walk from receiver's type; used when receiver type is known.
  • fallback: 'free-arity-narrowed' — after owner-scoped miss, search free-call candidates by arity only (Ruby uses this for implicit-self calls that miss their owner's MRO).
  • ancestryView: 'singleton' — walk singleton/class ancestry instead of instance ancestry (Ruby def self.foo bodies, so extend-ed methods are found).

Adding language behavior

  1. Implicit receivers — implement inferImplicitReceiver: return null if call already has a receiver; otherwise use findEnclosingClassInfo (ast-helpers.ts) to find the enclosing context, return ImplicitReceiverOverride with receiverSource: 'implicit-self', and optionally set hint for selectDispatch.
  2. Custom dispatch — implement selectDispatch: inspect receiverSource and hint, return DispatchDecision with primary, optional fallback, optional ancestryView; return null to keep shared defaults.
  3. MRO strategy — confirm mroStrategy is 'first-wins', 'c3', 'ruby-mixin', or 'none'; consumed by lookupMethodByOwnerWithMRO.

Ruby example (languages/ruby.ts + utils/ruby-self-call.ts): inferImplicitReceiver rewrites bare-identifier calls to self.method and sets hint to 'instance'/'singleton'; selectDispatch uses hint for ancestryView and adds fallback: 'free-arity-narrowed' for implicit-self calls.

Code references

Module Purpose
core/ingestion/call-types.ts DAG types: ReceiverEnriched, DispatchDecision, ImplicitReceiverOverride
core/ingestion/language-provider.ts Hook signatures: inferImplicitReceiver, selectDispatch
core/ingestion/call-processor.ts processCalls: stages 36
core/ingestion/model/resolve.ts lookupMethodByOwnerWithMRO: stage 5 MRO walk
core/ingestion/languages/ruby.ts Both hooks + mroStrategy: 'ruby-mixin'
core/ingestion/utils/ruby-self-call.ts Bare-call rewrite for inferImplicitReceiver

Coexistence with the scope-resolution pipeline

The Call-Resolution DAG is the legacy path. RFC #909 Ring 3 introduces a parallel scope-resolution pipeline (next section) that replaces stages 16 with a scope-indexed registry lookup. Both paths ship side-by-side and are gated per-language via MIGRATED_LANGUAGES + the REGISTRY_PRIMARY_<LANG> env var.

  • Unmigrated language → Call-Resolution DAG runs; scope-resolution phase is a no-op.
  • Migrated language (currently: Python, C#) → scope-resolution owns CALLS/ACCESSES/USES emission; the legacy DAG gates off for that language via isRegistryPrimary(lang) checks in call-processor.ts and import-processor.ts.
  • import-processor still populates importMap for migrated languages — heritage's ctx.resolve reads it to disambiguate parent classes. Only edge emission is gated.
  • CI runs BOTH paths for every migrated language on every PR (.github/workflows/ci-scope-parity.yml); both must pass.

Same-graph guarantee

Edges emitted by the scope-resolution pipeline and edges emitted by the legacy DAG are indistinguishable to downstream consumers (MCP tools, HTTP API, embeddings, group bridge):

  • Node identity — both paths use generateId(...) from lib/utils.ts, the same qualified-name keyspace, and the same node labels (File, Folder, Class, Method, Function, …). Overload disambiguation suffixes parameterTypes into the id consistently — see scope-resolution/graph-bridge/ids.ts and the legacy emitter in call-processor.ts.
  • Edge vocabulary — both paths emit the same reasons: 'import-resolved' | 'global' | 'local-call' | 'same-file' | 'interface-dispatch' | 'read' | 'write'. Migrating a language must not change which reasons consumers see for previously-resolved edges.
  • Confidence tier — both paths attach a numeric confidence to each edge using the same scale.

The CI parity workflow (.github/workflows/ci-scope-parity.yml) runs both paths against every migrated language's fixture corpus and fails on any divergence.

Semantic-model source of truth

Two independent invariants.

ParsedFile = the AST-level truth. ParsedFile (gitnexus-shared/src/scope-resolution/parsed-file.ts) is the single per-file artifact both resolution paths consume. Scope-resolution passes MUST NOT build a parallel parse representation. If a per-language hook needs AST-level facts that ParsedFile doesn't expose, it should reuse the orchestrator's treeCache (RunScopeResolutionInput.treeCache) rather than re-invoking parser.parse(...) on its own — the C# populateNamespaceSiblings hook is the reference implementation of this pattern.

SemanticModel = the symbol-level truth. SemanticModel (gitnexus/src/core/ingestion/model/semantic-model.ts) is the authoritative store for every symbol-indexed lookup (by nodeId, simpleName, qualifiedName, or filePath). Both paths read from here:

  • Legacy Call-Resolution DAG → call-processor Tier 1/2/3 via model.symbols.lookupExactAll, model.methods.lookupMethodByName, model.types.lookupClassByName, lookupMethodByOwnerWithMRO.
  • Scope-resolution pipeline → findOwnedMember, pickOverload, findExportedDefByName all consult model.methods / model.fields / model.symbols.

The scope-resolution pipeline additionally carries WorkspaceResolutionIndex for Scope-valued lookups (classScopeByDefId, moduleScopeByFile) that SemanticModel structurally cannot hold. No symbol-indexed duplicates exist outside SemanticModel.

Write / read phase contract. The model is mutable during three ordered phases and read-only afterward:

 Phase 1: legacy parse     ──► symbolTable.add fans into types/methods/fields
 Phase 2: scope-resolution ──► reconcileOwnership() registers corrected ownerIds
 Phase 3: finalize         ──► model.attachScopeIndexes(bundle) — one-shot freeze
 ─────────────────────────── phase boundary ───────────────────────────
 Read phase: all resolution passes + MCP + HTTP + embeddings see
             SemanticModel (read-only handle); writes are type-errors.

runScopeResolution narrows MutableSemanticModelSemanticModel at the phase boundary so downstream passes physically cannot mutate the model even accidentally.

Transitional: reconciliation pass. reconcileOwnership (scope-resolution/pipeline/reconcile-ownership.ts) is a shim for languages whose legacy extractor doesn't resolve enclosingClassId at parse time (Python class-body methods are the canonical case). It walks parsed.localDefs[i].ownerId after populateOwners and registers any missed methods/fields into the model. Idempotent — safe to re-run, safe alongside languages whose legacy extractor already carries ownerId (C#).

The architectural end state is for every language's parse-time extractor to emit the correct ownerId directly, making reconciliation a no-op (tracked as a follow-up refactor). The dev-mode validator validateOwnershipParity surfaces any drift via onWarn under NODE_ENV !== 'production' && VALIDATE_SEMANTIC_MODEL !== '0'.

References: semantic-model.ts file-head (full write/read contract); contract/scope-resolver.ts Contract Invariant I9 (scope-resolution-side rule).


Scope-Resolution Pipeline (RFC #909 Ring 3)

Language-agnostic registry-primary resolver. Replaces the Call-Resolution DAG for migrated languages. Adding a language is one interface implementation (ScopeResolver) plus two registrations — no changes to shared code, no new pipeline phase.

Pipeline stages

 ParsedFile[]  (extractParsedFile per file)
    │  finalizeScopeModel (+ provider hooks)
    ▼
 ScopeResolutionIndexes
    │  resolveReferenceSites  (via MethodRegistry.lookup)
    ▼
 ReferenceIndex
    │  emitReceiverBoundCalls  ── FIRST
    │  emitFreeCallFallback    ── THEN
    │  emitReferencesViaLookup ── LAST (uses handledSites)
    │  emitImportEdges
    ▼
 KnowledgeGraph  (IMPORTS / CALLS / ACCESSES / INHERITS / USES)

Orchestrator: runScopeResolution(input, provider) in scope-resolution/pipeline/run.ts. Pipeline phase: scopeResolutionPhase in scope-resolution/pipeline/phase.ts — iterates SCOPE_RESOLVERS ∩ MIGRATED_LANGUAGES, reads per-file Trees from the parse phase's scopeTreeCache, disposes the cache at the end.

ScopeResolver contract

Single interface a language implements to plug into the pipeline. Contract fully documented in scope-resolution/contract/scope-resolver.ts.

Hook Purpose
languageProvider Base LanguageProvider (tree-sitter query, emitScopeCaptures, import/binding interpreters, hooks)
populateOwners(parsed) Fill deferred ownerId fields on method defs (captures can't always know the owning class at parse time)
buildMro(graph, parsed, nodeLookup) Produce mroByClassDefId: Map<DefId, DefId[]> — C3, Ruby-mixin, or first-wins per language
resolveImportTarget(target, fromFile, allFiles) (rawImportPath, sourceFile) → targetFilePath (PEP-328 for Python, etc.)
mergeBindings(existing, incoming, scopeId) Shadowing / LEGB precedence
arityCompatibility Provider consumed by registry during MethodRegistry.lookup Step 2
importEdgeReason Confidence-tier string for IMPORTS edge reason field
propagatesReturnTypesAcrossImports? Opt out of cross-file return-type propagation (default on)
fieldFallbackOnMethodLookup? Statically-typed languages turn this OFF — the heuristic over-connects (default on)
unwrapCollectionAccessor? Property-style collection views (data.Values on Dictionary-like receivers) — default off
collapseMemberCallsByCallerTarget? One CALLS edge per (caller, target) instead of per-site — default off
populateNamespaceSiblings? Cross-file implicit visibility (compiler-implicit namespace sharing) — default off; ctx carries treeCache
hoistTypeBindingsToModule? Walk up to Module scope when looking up a method's return-type typeBinding — default off; enable only when bindings are stored at module level

Per-language registration

  1. Implement ScopeResolver in languages/<lang>/scope-resolver.ts.
  2. Add entry to SCOPE_RESOLVERS in scope-resolution/pipeline/registry.ts.
  3. Add the language to MIGRATED_LANGUAGES in registry-primary-flag.ts when the shadow-harness corpus parity ≥ 99% fixtures / ≥ 98% corpus.

CI auto-discovers the set via tsx. No workflow edit required.

Code references

Module Purpose
scope-resolution/contract/scope-resolver.ts ScopeResolver interface + shared types
scope-resolution/pipeline/run.ts Generic orchestrator
scope-resolution/pipeline/phase.ts Pipeline-phase wrapper (deps: parse, structure)
scope-resolution/pipeline/registry.ts SCOPE_RESOLVERS map
scope-resolution/passes/*.ts Reference-resolution passes (receiver-bound, free-call fallback, compound-receiver, MRO, cross-file return-type propagation)
scope-resolution/graph-bridge/*.ts CLI-local translation from resolved references → KnowledgeGraph edges
scope-resolution/scope/*.ts Generic scope-chain walkers + namespace targets
scope-resolution/workspace-index.ts Build-once O(1) lookup index
registry-primary-flag.ts MIGRATED_LANGUAGES set + isRegistryPrimary(lang)
languages/python/index.ts Python ScopeResolver hooks + known-limitation docs
languages/python/captures.ts emitPythonScopeCaptures (honors cross-phase Tree cache)
languages/csharp/index.ts C# ScopeResolver hooks + known-limitation docs
languages/csharp/captures.ts emitCsharpScopeCaptures (honors cross-phase Tree cache)
languages/csharp/namespace-siblings.ts Cross-file implicit-namespace visibility hook (reads treeCache)

Performance notes

  • Cross-phase Tree cache: parse phase writes Trees into scopeTreeCache (separate from the chunk-local astCache) ONLY for languages with emitScopeCaptures. Scope-resolution reads from it to skip the second parse. Cleared at end of the phase. Workers leave the cache empty — Trees can't cross MessageChannels; cache miss = fresh parse. PROF_SCOPE_RESOLUTION=1 emits hit/miss counters and a worker-engaged warning.
  • Typed relationship iteration: heritage + MRO walk only the EXTENDS / IMPLEMENTS / HAS_METHOD edges via iterRelationshipsByType, not the full relationship map.
  • Workspace-resolution-index: O(1) findOwnedMember / findExportedDef / classScopeByDefId built once per run.

Language-agnostic graph feeding

16 languages → single unified graph. Four abstraction layers:

 Unified Graph Schema (44 node types, 21 relationship types)
           ↑
 Unified Resolution (3-tier name lookup + MRO walk)
           ↑
 Language Providers (import semantics, type config, export checker, MRO strategy)
           ↑
 Tree-Sitter Queries (per-language S-expressions, unified capture tags)

Language providers

Each language implements LanguageProvider (language-provider.ts). Key fields:

Field Purpose
id, extensions Language identity and file matching
treeSitterQueries S-expression queries for AST extraction
importSemantics named / wildcard-leaf / wildcard-transitive / namespace
importResolver Language-specific path → file resolution
exportChecker Public/exported symbol detection
typeConfig Type annotation extraction rules
mroStrategy first-wins / c3 / none

16 providers in languages/index.ts via satisfies Record<SupportedLanguages, LanguageProvider> — missing a language is a compile error.

Unified capture tags

Per-language tree-sitter queries use different AST node names but produce the same semantic capture tags: @definition.class, @definition.function, @call.name, @import.source, @heritage.extends. Downstream extraction needs no language branching. Defined in tree-sitter-queries.ts.

Import resolution

Per-language import resolution uses the configs + factory pattern (like call/method/class extractors). Each language declares an ImportResolutionConfig in import-resolvers/configs/, listing an ordered chain of ImportResolverStrategy functions. createImportResolver() (in resolver-factory.ts) composes them: first non-null result wins. Low-level helpers shared across strategies live alongside the configs in import-resolvers/ (e.g. go.ts, rust.ts, python.ts).

Unified 3-tier algorithm (model/resolution-context.ts), per-language importSemantics controls which tier activates:

Tier Confidence Mechanism
1 — same-file 0.95 Symbol table for caller's file
2 — import-scoped 0.9 NamedImportMap chains (named) or all files in importMap (wildcard)
3 — global 0.5 O(1) index lookups: class, impl, callable. Fallback only
Import strategy Languages Behavior
named TS, JS, Java, C#, Rust, PHP, Kotlin Only explicitly imported names visible
wildcard-leaf Go, Ruby, Swift, Dart Whole-package import, no transitive re-exports
wildcard-transitive C, C++ #include closure chains through re-exports
namespace Python Module aliases resolved at call site

Chunked parse-and-resolve

parse processes files in ~20 MB byte-budget chunks to bound memory. Per chunk:

  1. Worker pool dispatches files (or sequential fallback via skipWorkers)
  2. Each worker: detect language → load grammar → run queries → return unified ParseWorkerResult
  3. Synthesize wildcard bindings (wildcard-synthesis.ts)
  4. Resolve imports and heritage
  5. Collect BindingAccumulator entries for cross-file propagation

Workers: workers/worker-pool.ts, workers/parse-worker.ts.

Heritage and MRO

All languages emit unified ExtractedHeritage (child, parent, EXTENDS/IMPLEMENTS). MRO phase walks the heritage graph using per-language strategy:

  • first-wins — Java, C#, C++, TS, Ruby, Go
  • c3 — Python (C3 linearization)
  • none — single-inheritance languages

Unified walk: lookupMethodByOwnerWithMRO() in model/resolve.ts.


Full analysis flow

runFullAnalysis in run-analyze.ts orchestrates everything around the pipeline:

CLI (analyze.ts) → runFullAnalysis(repoPath, options, callbacks)
  1. Early exit if lastCommit == HEAD (unless --force)     [0%]
  2. Cache existing embeddings from prior index             [0%]
  3. runPipelineFromRepo() → KnowledgeGraph                [0-60%]
  4. Clean up legacy KuzuDB files                          [60%]
  5. initLbug() → loadGraphToLbug() via CSV streaming      [60-85%]
  6. Create FTS indexes (File, Function, Class, Method...) [85-90%]
  7. Restore cached embeddings (batch insert)              [88%]
  8. Generate new embeddings if --embeddings               [90-98%]
  9. Save metadata + register repo + update .gitignore     [98-100%]
 10. Generate AI context files (AGENTS.md, CLAUDE.md)      [100%]

Options: --force (rebuild regardless), --embeddings (opt-in, skipped if >50k nodes), --skipGit, --noStats.

Storage

<repo>/.gitnexus/
  ├── lbug           # LadybugDB database
  ├── lbug.wal       # Write-ahead log
  ├── lbug.lock      # Single-writer lock
  └── meta.json      # lastCommit, indexedAt, stats

~/.gitnexus/
  └── registry.json  # Global repo registry (MCP discovery)

Managed by repo-manager.ts.

LadybugDB schema

Defined in lbug/schema.ts. Separate node tables per type, single CodeRelation table.

Node tables: File, Folder, Function, Class, Interface, Method, Constructor, CodeElement, Struct, Enum, Macro, Typedef, Union, Namespace, Trait, Impl, TypeAlias, Const, Static, Property, Record, Delegate, Annotation, Template, Module, Community, Process, Route, Tool, Section, Embedding.

Relation types (CodeRelation.type): CONTAINS, DEFINES, CALLS, IMPORTS, EXTENDS, IMPLEMENTS, HAS_METHOD, HAS_PROPERTY, ACCESSES, METHOD_OVERRIDES, METHOD_IMPLEMENTS, MEMBER_OF, STEP_IN_PROCESS, HANDLES_ROUTE, FETCHES, HANDLES_TOOL, ENTRY_POINT_OF.

Embeddings (src/core/embeddings/): Snowflake arctic-embed-xs (384D). Embeddable: File, Function, Class, Method, Interface. Incremental via SHA1 content hash. Separate Embedding table.

Search (src/core/search/): Hybrid BM25 + semantic vector, merged via Reciprocal Rank Fusion (K=60).

Known limitations

Overloaded method resolution

Node IDs use arity suffix (#<paramCount>): Method:file:Class.method#1 vs #2.

Same-arity disambiguation: type-hash suffix ~type1,type2 when collision detected and type annotations present. Languages without types (Python, Ruby, JS) use arity-only. TS/JS overload signatures excluded (collapse to implementation body). See #651.

C++ const-qualified: $const suffix after type-hash when non-const collision exists: Method:file:Container.begin#0$const.

Generic/template types: type-hash uses rawType (full AST text including generics): ~vector<int> vs ~vector<std::string>.

ID stability: collision-only tags mean IDs change when overloads are added. save#1 becomes save#1~int when save(String) is added.

Variadic matching: confidence 0.7 when one side is variadic and the other has fixed count.

METHOD_IMPLEMENTS confidence tiering:

Match quality Confidence
Exact parameter types match 1.0
Arity match, types unavailable 1.0
Variadic vs fixed 0.7
Insufficient info 0.7
  • MIGRATION.md — breaking changes and migration guidance
  • RUNBOOK.md — operational commands and recovery
  • GUARDRAILS.md — safety boundaries for humans and agents
  • TESTING.md — how to run tests
  • AGENTS.md / CLAUDE.md — agent workflows and tool usage