React-Docgen: Add tsconfig fallback chain and warning for monorepos

[viditkbhatnagar]

What this PR does

Fixes #24585

In monorepo setups (e.g., Nx, Turborepo), the root directory often has
tsconfig.base.json instead of tsconfig.json. Storybook's tsconfig
resolution silently failed, causing react-docgen-typescript to produce
no controls with zero warnings.

Changes

• utils.ts — findTsconfigPath() now tries tsconfig.json →
  tsconfig.base.json → tsconfig.app.json in order, with a warning
  log when using a fallback
• reactDocgenTypescript.ts — Warns when no tsconfig variant is
  found, telling the user TypeScript controls won't work
• react-docgen.ts / react-docgen-loader.ts — Consistent
  fallback chain for path alias resolution in Vite and Webpack
• utils.test.ts — 5 new tests covering all scenarios

How to test

1. Create a monorepo with tsconfig.base.json in root (no tsconfig.json)
2. Set up a Storybook with react-docgen-typescript
3. Verify controls are now generated correctly
4. Verify a warning is logged when falling back to tsconfig.base.json
5. Remove all tsconfig variants and verify a clear warning is shown

Checklist

• Bug fix
• Tests added
• No breaking changes

Summary by CodeRabbit

• Bug Fixes & Improvements

  • Broadened TypeScript config discovery to try common alternative filenames for better multi-package/monorepo support.
  • Added a runtime warning when no TypeScript config is found (affects prop documentation behavior).

• Tests

  • Added tests for config discovery priority and warning behavior.

[coderabbitai]

📝 Walkthrough

Walkthrough

Search for TypeScript config now tries tsconfig.json, then tsconfig.base.json, then tsconfig.app.json (bounded by projectRoot). Plugins/loaders use this expanded lookup; renderer logs a warning when no tsconfig is found. Tests added for priority and absence cases.

Changes

Cohort / File(s)	Summary
Plugins & Loaders code/frameworks/react-vite/src/plugins/react-docgen.ts, code/presets/react-webpack/src/loaders/react-docgen-loader.ts	Tsconfig discovery now checks ordered candidates tsconfig.json, tsconfig.base.json, tsconfig.app.json (search bounded by project root). Downstream TsconfigPaths usage unchanged.
Renderer: react-docgen integration code/renderers/react/src/componentManifest/reactDocgenTypescript.ts	Import logger and emit logger.warn when no tsconfig is found before initializing react-docgen-typescript program.
Core utility code/renderers/react/src/componentManifest/utils.ts	Replaced single-file upward search with ordered candidate search returning first match or undefined; preserves cached wrapper.
Tests code/renderers/react/src/componentManifest/utils.test.ts	Added tests/mocks for findTsconfigPath: validates priority order (json → base → app), absence case, cache invalidation, and warning expectations.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• Core: Fix import statement for react-docgen-typescript #33589: Similar changes to react-docgen TypeScript config discovery and feeding tsconfig into react-docgen.
• React: Improve automatic component, automatic imports, support barrel files and enhance story filtering #32939: Overlaps with modifications to react renderer docgen utilities and alternate tsconfig filename handling.
• React: Implement manifests/component.json for React #32751: Touches componentManifest/react-docgen tsconfig resolution and path-mapping logic related to these changes.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

code/renderers/react/src/componentManifest/utils.test.ts (1)

207-259: Consider wrapping logger with vi.mocked() for typed mock assertions.

For consistency with mocking patterns in the codebase (e.g., manifests.test.ts), wrap the entire logger object when asserting on its methods: expect(vi.mocked(logger).warn).not.toHaveBeenCalled() at lines 207, 242, and 259.

This provides type safety and aligns with the guideline: "Use vi.mocked() to type and access the mocked functions in Vitest tests."

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@code/renderers/react/src/componentManifest/utils.test.ts` around lines 207 -
259, The tests call expect(logger.warn).not.toHaveBeenCalled() in several
places; update those assertions to use Vitest's typed mock helper by wrapping
the logger with vi.mocked, e.g., replace expect(logger.warn)... with
expect(vi.mocked(logger).warn).not.toHaveBeenCalled() in the tests that
reference logger (the ones around the findTsconfigPath tests), so all logger
method assertions use vi.mocked(logger) for proper typed mocking.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@code/renderers/react/src/componentManifest/utils.test.ts`:
- Around line 191-254: The tests currently set
vi.mocked(find.up).mockImplementation inline inside individual tests; move this
mock setup into the existing beforeEach so all mock behavior follows repo Vitest
rules: create a local mapping variable (e.g. findUpMap) in the test file, set a
default mapping in beforeEach and call
vi.mocked(find.up).mockImplementation((name) => findUpMap[name]); then in each
test set/override entries on findUpMap (or assign a new map) before invoking
findTsconfigPath so tests still return the desired filenames (tsconfig.json,
tsconfig.base.json, tsconfig.app.json or undefined) and preserve assertions such
as expect(logger.warn).not.toHaveBeenCalled().

---

Nitpick comments:
In `@code/renderers/react/src/componentManifest/utils.test.ts`:
- Around line 207-259: The tests call expect(logger.warn).not.toHaveBeenCalled()
in several places; update those assertions to use Vitest's typed mock helper by
wrapping the logger with vi.mocked, e.g., replace expect(logger.warn)... with
expect(vi.mocked(logger).warn).not.toHaveBeenCalled() in the tests that
reference logger (the ones around the findTsconfigPath tests), so all logger
method assertions use vi.mocked(logger) for proper typed mocking.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 4650ae5f-c8a1-4dfd-b46d-02abf259b79c

📥 Commits

Reviewing files that changed from the base of the PR and between 3a0725b and ee42d68.

📒 Files selected for processing (1)

• code/renderers/react/src/componentManifest/utils.test.ts