Merge e8f56e6dc5 into 31c9d9223e

gitnexus/src/core/ingestion/route-extractors/java-const-resolver.ts

@@ -619,12 +619,20 @@ function foldOperands(
 /**
  * Fold an inline operand list (e.g. `API_CIS_V1 + "summary/save"`) against
  * `fileKey`, or null when any piece is unresolvable (skip floor).
+ *
+ * An empty result is a SUCCESS, not a skip. `static final String ROOT = "";`
+ * folds to `""`, which `joinPath` then resolves against the type-level prefix
+ * exactly as it resolves the literal `@GetMapping("")`. Collapsing it into
+ * `null` would make a resolved-empty path indistinguishable from an
+ * unresolvable one — the skip floor is reserved for "could not fold", and
+ * nothing else in the resolver conflates the two: `resolveOperands` in the
+ * shared core returns `foldExpr` unfiltered, and `resolveJavaConstant` returns
+ * `""` for an empty constant.
  */
 export function foldJavaOperands(
   fileKey: string,
   operands: readonly Operand[],
   repo: RepoConstants,
 ): string | null {
-  const out = foldOperands(fileKey, operands, newFoldState(repo), 0);
-  return out === '' ? null : out;
+  return foldOperands(fileKey, operands, newFoldState(repo), 0);
 }

gitnexus/test/unit/group/java-const-route-parity.test.ts

@@ -211,3 +211,46 @@ public class OrderController {
     expect(ingestionRoutes(files)).toEqual(['POST /api/v1/orders']);
   });
 });
+
+describe('an empty-valued constant route matches its literal spelling', () => {
+  // Before this fix the two spellings diverged: `@GetMapping("")` was kept and
+  // `@GetMapping(ApiPaths.ROOT)` with `ROOT = ""` was dropped, because the fold
+  // collapsed a resolved-empty result into the skip floor. The class-level
+  // prefix is what makes an empty method path meaningful, so the parity is
+  // asserted with one present.
+  const ROOT_CONSTS = `package com.example;
+public class ApiPaths {
+  public static final String ROOT = "";
+}`;
+
+  const controller = (mapping: string): string => `package com.example;
+import com.example.ApiPaths;
+@RequestMapping("/api/v1")
+public class RootController {
+  @GetMapping(${mapping})
+  public void root() {}
+}`;
+
+  it('resolves the constant spelling to the same path as the literal one', () => {
+    const literal = { [CTL]: controller('""') };
+    const constant = { [CONSTS]: ROOT_CONSTS, [CTL]: controller('ApiPaths.ROOT') };
+
+    expect(groupProviders(constant)).toEqual(groupProviders(literal));
+    expect(ingestionRoutes(constant)).toEqual(ingestionRoutes(literal));
+  });
+
+  it('emits the route on both sides rather than dropping it', () => {
+    // Deliberately NOT asserting the two sides produce the same string here.
+    // They do not, and they did not before this change either: measured on the
+    // LITERAL spelling, which no part of this change touches, the group side
+    // emits `/api/v1/` (`joinPath` appends `/` before an empty method path)
+    // while ingestion emits `/api/v1`. That trailing-slash divergence is a
+    // separate pre-existing defect; the fix here only makes the constant
+    // spelling reach it too, instead of silently dropping the route. The test
+    // above is what pins the parity that this change is responsible for —
+    // constant behaves as literal, on each side.
+    const files = { [CONSTS]: ROOT_CONSTS, [CTL]: controller('ApiPaths.ROOT') };
+    expect(groupProviders(files)).toEqual(['GET /api/v1/']);
+    expect(ingestionRoutes(files)).toEqual(['GET /api/v1']);
+  });
+});

gitnexus/test/unit/java-route-const-resolver.test.ts

@@ -792,3 +792,66 @@ describe('text blocks keep the skip floor', () => {
     expect(extractJavaModuleConstants(parse(src)).literals.has('X')).toBe(false);
   });
 });
+
+describe('an empty fold is a success, not a skip', () => {
+  // `null` from this fold is the SKIP FLOOR: it means "a piece was
+  // unresolvable", and every caller acts on it by dropping the route. An
+  // empty-valued constant is not that case — it resolved, to the empty string.
+  // Spring reads `@GetMapping(ROOT)` with `ROOT = ""` exactly as it reads
+  // `@GetMapping("")`, and the group extractor's literal branch already keeps
+  // the latter. Collapsing the two silently lost the route for the constant
+  // spelling alone.
+  const EMPTY = 'src/main/java/com/example/Paths.java';
+
+  it('folds a constant whose value is the empty string', () => {
+    const repo = repoOf({
+      [EMPTY]: `package com.example;
+public class Paths { public static final String ROOT = ""; }`,
+    });
+    expect(foldJavaOperands(EMPTY, [{ kind: 'ref', name: 'ROOT' }], repo)).toBe('');
+  });
+
+  it('concatenating empty constants folds to the empty string', () => {
+    const repo = repoOf({
+      [EMPTY]: `package com.example;
+public class Paths {
+  public static final String A = "";
+  public static final String B = "";
+}`,
+    });
+    expect(
+      foldJavaOperands(
+        EMPTY,
+        [
+          { kind: 'ref', name: 'A' },
+          { kind: 'ref', name: 'B' },
+        ],
+        repo,
+      ),
+    ).toBe('');
+  });
+
+  it('still floors to skip when a piece is genuinely unresolvable', () => {
+    // The control: the two outcomes have to stay distinguishable, or the fix
+    // would trade one conflation for another.
+    const repo = repoOf({
+      [EMPTY]: `package com.example;
+public class Paths { public static final String ROOT = compute(); }`,
+    });
+    expect(foldJavaOperands(EMPTY, [{ kind: 'ref', name: 'ROOT' }], repo)).toBeNull();
+  });
+
+  it('agrees with resolveJavaConstant, which never collapsed empty to null', () => {
+    // The binding used to disagree with itself: the single-constant resolver
+    // returns `""` (pinned by the 30-level DAG case above, whose every
+    // intermediate value is empty), and `resolveOperands` in the shared
+    // language-agnostic core returns `foldExpr` unfiltered. Only this fold
+    // collapsed.
+    const repo = repoOf({
+      [EMPTY]: `package com.example;
+public class Paths { public static final String ROOT = ""; }`,
+    });
+    expect(resolveJavaConstant(EMPTY, 'ROOT', repo)).toBe('');
+    expect(foldJavaOperands(EMPTY, [{ kind: 'ref', name: 'ROOT' }], repo)).toBe('');
+  });
+});