🪵 fix: Restore Winston Format Factory Shape In Test Mocks

[JorgeCosta87]

Summary

The four jest.mock('winston', …) setups in the test suite return a shape that doesn't satisfy real winston's Format-factory contract. As long as nothing forces winston.format() to be evaluated at module-load time, the tests pass — but @librechat/data-schemas/dist/config/parsers.cjs:52 does exactly that, so any test file whose import graph reaches @librechat/data-schemas (directly or transitively) can fail to load on environments where Jest's mock-hoisting actually hits this path.

Affected files:

• api/test/__mocks__/logger.js — (fn) => fn returns the inner transform fn directly. When parsers.cjs does const redactFormat = winston.format(fn) and then parsers.redactFormat(), the inner fn is invoked with no info argument → TypeError: Cannot read properties of undefined (reading 'level') at parsers.ts:63.
• packages/api/src/agents/__tests__/memory.test.ts
• packages/api/src/agents/__tests__/run-summarization.test.ts
• packages/api/src/agents/__tests__/initialize.test.ts — format is a plain object with combine/colorize/simple only, so winston.format(fn) throws TypeError: winston.format is not a function. Once that's patched, the dist code then trips over missing winston.format.printf, winston.addColors, new winston.transports.DailyRotateFile(...).

The bug was introduced when DB layers were extracted into @librechat/data-schemas (#7650, May 2025) and the side-effecting winston.format() call moved with them. The test mocks were never updated to follow.

Why it doesn't fail in current CI on main: the failure depends on subtleties of Jest's jest.mock hoisting interaction with the workspace symlink chain — happens reproducibly on Node 24.x and on some Linux runner configurations, doesn't trigger on the GitHub Actions Ubuntu / Node 20.19 combination that current CI uses. The mock is wrong against the API contract regardless; this fix removes the latent failure across all supported environments.

Change Type

• Bug fix (non-breaking change which fixes an issue)

Testing

Repro on main (Node 24.9.0, Linux):

git checkout main
npm ci
npm run build:data-provider && npm run build:data-schemas && npm run build:api
cd packages/api && npx jest src/agents/__tests__/memory.test.ts
# → TypeError: winston.format is not a function
#   at ../data-schemas/src/config/parsers.ts:62

With this PR applied:

cd packages/api && npx jest src/agents/__tests__/memory.test.ts src/agents/__tests__/run-summarization.test.ts src/agents/__tests__/initialize.test.ts
# → 3 suites, 106 tests, all pass

Test Configuration

• Node 24.9.0 (also verified the fix works on Node 20.19.6)
• Ubuntu / WSL2
• Jest 30.2.0
• Fresh build of packages/{data-provider,data-schemas,api} per the contributor guide

What the fix does

For all four mocks, winston.format becomes a callable factory that mirrors real winston's shape:

format: Object.assign(jest.fn((fn) => () => ({ transform: fn })), {
  combine: jest.fn(),
  colorize: jest.fn(),
  simple: jest.fn(),
  label: jest.fn(),
  timestamp: jest.fn(),
  printf: jest.fn(),
  errors: jest.fn(),
  splat: jest.fn(),
  json: jest.fn(),
}),
addColors: jest.fn(),
transports: {
  Console: jest.fn(),
  DailyRotateFile: jest.fn(),
  File: jest.fn(),
},

winston.format(fn) now returns a thunk that yields { transform: fn }. Module-load completes cleanly because nothing invokes the inner transform at import time; winston's pipeline (not exercised under mocks) is the only thing that would ever call .transform(info).

api/test/__mocks__/logger.js keeps its property-on-function style — the only change there is the closure body returns () => ({ transform: fn }) instead of fn.

Checklist

• My code adheres to this project's style guidelines (ran prettier --write + eslint)
• I have performed a self-review of my own code
• I have commented in any complex areas of my code (each mock now explains why format needs to be callable)
• I have made pertinent documentation changes (no docs affected — test-only patch)
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective (the existing tests now pass on previously-failing environments)
• Local unit tests pass with my changes (cd packages/api && npx jest src/agents/__tests__/ → green)
• Any changes dependent on mine have been merged and published in downstream modules. (n/a — test-only)
• A pull request for updating the documentation has been submitted. (n/a — test-only)

[danny-avila]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Another round soon, please!

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