fabro/lib/crates
Bryan Helmkamp 2b53917759
fix(validate): treat undefined template vars in @file prompts as warnings (#290)
## Summary

`fabro validate` had inconsistent behavior for undefined template
variables depending on whether the prompt was inline or loaded via an
`@file` reference. Inline `{{ inputs.foo }}` produced a warning and
validation passed; the same expression inside a `@file`-imported prompt
produced a hard validation error.

Fixes #286.

## Root cause

Two template-rendering passes with different strictness, applied to
disjoint inputs:

1. **DOT-source pass**
(`lib/crates/fabro-workflow/src/operations/create.rs`) honored
`RenderMode::Structural` for `fabro validate` — undefined variables
downgraded to a `Severity::Warning` diagnostic, then lenient render
finished the job.
2. **Per-attribute pass**
(`lib/crates/fabro-workflow/src/transforms/variable_expansion.rs`)
inside `TemplateTransform` was always strict and had no `RenderMode`
awareness. Because `FileInliningTransform` runs *before*
`TemplateTransform`, expressions inside `@file` content only ever
encountered the strict pass.

## Fix

- Plumb `RenderMode` through `TransformOptions` into
`TemplateTransform`.
- In `RenderMode::Structural`, the transform catches
`TemplateError::UndefinedVariable` per attribute, emits a warning
diagnostic, and falls back to `render_lenient`.
- Diagnostics flow through a new `Transformed.diagnostics` field into
`Validated` alongside lint output.
- Diagnostics now include `node_id` when the undefined variable was
found inside a node attribute, which is more useful than the previous
"at line 1" location.
- `RenderMode` and the shared `template_undefined_variable_diagnostic`
helper moved to `pipeline/types.rs` so the transform layer can reach
them without a circular dep.

Strict mode (`fabro run`, preflight) is unchanged — undefined inputs
still hard-fail before a run is created.

## Behavior

Illustrative output shapes (variable names and line numbers depend on
the fixture):

Inline prompt (unchanged):
```
warning: undefined template variable `inputs.<name>` at line <n> (template_undefined_variable)
Validation: OK
```

`@file`-imported prompt (previously a hard error, now matches inline —
node-attributed instead of line-attributed):
```
warning [node: <id>]: undefined template variable `inputs.<name>` in node `<id>` (template_undefined_variable)
Validation: OK
```

## Test plan

- [x] `cargo nextest run --workspace` — 5773/5773 passing
- [x] `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D
warnings` clean
- [x] `cargo +nightly-2026-04-14 fmt --check --all` clean
- [x] New regression test
`bare_fabro_with_unbound_inputs_in_imported_prompt_validates_structurally_with_warning`
in `lib/crates/fabro-cli/tests/it/cmd/validate.rs` against new fixture
`test/templated_unbound_imported/`
- [x] Existing
`bare_fabro_with_unbound_inputs_validates_structurally_with_warning` and
`strict_render_hard_fails_on_unbound_inputs` still pass — verifies
inline structural and run-start strict behavior are both preserved
- [x] Manual reproduction of the exact inputs from the issue now
succeeds with a warning

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Aleksi Asikainen <1086393+salieri@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-16 17:31:22 -04:00
..
build-support fix(build): refresh embedded git sha on branch commits 2026-05-09 14:10:04 -04:00
fabro-acp feat(errors): add structured failure diagnostics (#277) 2026-05-16 13:25:07 -04:00
fabro-agent feat(session): add server-backed agent sessions (#278) 2026-05-16 17:25:05 -04:00
fabro-api feat(session): add server-backed agent sessions (#278) 2026-05-16 17:25:05 -04:00
fabro-auth refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-checkpoint Make git metadata sandbox-native 2026-04-27 21:43:15 -07:00
fabro-cli fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-client feat(session): add server-backed agent sessions (#278) 2026-05-16 17:25:05 -04:00
fabro-config refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-core feat(errors): add structured failure diagnostics (#277) 2026-05-16 13:25:07 -04:00
fabro-dev fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-devcontainer refactor(static): centralize env var names 2026-04-24 12:29:51 -04:00
fabro-dump feat(sandbox): prepare clone layout for multi-repo runs (#250) 2026-05-14 09:38:20 -04:00
fabro-github fix(github): refresh installation tokens during workflows 2026-05-06 07:15:18 -04:00
fabro-graphviz refactor: remove compatibility shims (#281) 2026-05-16 15:29:25 -04:00
fabro-hooks refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-http refactor(static): centralize env var names 2026-04-24 12:29:51 -04:00
fabro-install fix(server): default foreground logs to stdout 2026-05-06 12:41:52 -04:00
fabro-interview Wire end-to-end steering for running agents (#209) 2026-05-05 15:34:16 -04:00
fabro-llm refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-macros refactor(dev): simplify generated docs tooling 2026-04-24 18:41:00 -04:00
fabro-manifest fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-mcp feat(cli): add Fabro MCP server (#236) 2026-05-11 18:20:50 -04:00
fabro-mcp-server fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-model refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-oauth fix(error): preserve remaining error context 2026-05-02 10:51:15 -04:00
fabro-options-metadata refactor(dev): simplify generated docs tooling 2026-04-24 18:41:00 -04:00
fabro-proc refactor(static): centralize env var names 2026-04-24 12:29:51 -04:00
fabro-redact refactor(integrations): make chat integrations Slack-only 2026-05-09 11:43:16 -04:00
fabro-sandbox fix(sandbox): clone Daytona repos under /home/daytona/repos (#285) 2026-05-16 13:47:54 -04:00
fabro-server fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-slack feat(slack): render plan summary + run link in interview messages (re #253, stacked on #252) (#254) 2026-05-13 07:41:54 -04:00
fabro-spa feat(dev): gitignore embedded spa assets 2026-04-26 21:31:11 -04:00
fabro-static refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-store feat(session): add server-backed agent sessions (#278) 2026-05-16 17:25:05 -04:00
fabro-telemetry refactor(workflow): remove retro stage (#230) 2026-05-09 10:18:20 -04:00
fabro-template fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00
fabro-test feat(cli): add Fabro MCP server (#236) 2026-05-11 18:20:50 -04:00
fabro-tracker fix(github): refresh installation tokens during workflows 2026-05-06 07:15:18 -04:00
fabro-types feat(session): add server-backed agent sessions (#278) 2026-05-16 17:25:05 -04:00
fabro-util feat(errors): add structured failure diagnostics (#277) 2026-05-16 13:25:07 -04:00
fabro-validate refactor(llm): split provider identity from adapters (#280) 2026-05-16 13:13:41 -04:00
fabro-vault refactor(api): unify secret metadata types 2026-04-29 20:26:13 -04:00
fabro-workflow fix(validate): treat undefined template vars in @file prompts as warnings (#290) 2026-05-16 17:31:22 -04:00