fix(linter): do not infer projects from package.json files outside the workspaces

[FrozenPandaz]

Current Behavior

@nx/eslint's inference plugin globs **/package.json, and splitConfigFiles promotes every matching directory to a project root:

const PROJECT_CONFIG_FILENAMES = ['project.json', 'package.json'];

for (const configFile of configFiles) {
  if (PROJECT_CONFIG_FILENAMES.includes(basename(configFile))) {
    projectRoots.add(dirname(configFile));   // <- no workspaces filter
  } else {
    eslintConfigFiles.push(configFile);
  }
}

Nested package.json files are very often markers, not projects — a {"sideEffects": false} beside a bundle, a polyfill directory stub, a workers-site folder. Those have no name, so once promoted they fail the entire graph:

NX   Failed to process project graph.
The projects in the following directories have no name provided:
  - fixtures/legacy-site-app/workers-site
  - packages/unenv-preset/src/runtime/polyfill

The throw is unconditional (project-nodes-manager.ts:268), so one stray marker file takes down the whole workspace — and the error names a directory the user never asked to be a project, which makes it hard to trace back to the linter plugin.

Nx core's own package-json plugin already guards against exactly this in packages/nx/src/plugins/package-json/create-nodes.ts:

if (!isInPackageManagerWorkspaces && !isNextToProjectJson(packageJsonPath)) {
  // Skip if package.json is not part of the package.json workspaces and not next to a project.json.
  return null;
}

@nx/eslint did not.

Expected Behavior

Package.json files are filtered through the package manager's workspaces globs before becoming project roots, reusing the core helpers (buildPackageJsonPatterns / buildPackageJsonWorkspacesMatcher) so the two plugins cannot drift. A package.json sitting next to a project.json is still a project regardless of the globs.

The non-obvious part

The "no workspaces declared" case has to skip the filter entirely:

const isInPackageManagerWorkspaces = patterns.positive.length
  ? buildPackageJsonWorkspacesMatcher(patterns)
  : () => true;

With no workspaces field, buildPackageJsonPatterns returns empty patterns and the matcher rejects everything — including the root package.json of a standalone repo that is the project. Filtering unconditionally deletes the root project and breaks the existing '.' tests. This guard is load-bearing, not defensive.

Validation

Test-first. The new spec was confirmed red against the unfixed plugin, and the failure is precisely the bug:

- Expected  - 0
+ Received  + 1
  Array [
    "packages/a",
+   "packages/a/src/runtime/polyfill",
  ]

Green after the fix. build, test and lint all pass for @nx/eslint (31 tests; the single remaining lint warning is a pre-existing skipped test at plugin.spec.ts:89).

No collateral damage. I captured nx show projects for this repo with and without the change: 145 projects, byte-identical both ways. The fix only removes bogus promotions — it does not drop a single real project. The pre-existing test asserting that a nameless apps/my-app/package.json does get a node (no workspaces declared) still passes, which is the guard above doing its job.

Related Issue(s)

NXC-4746 — https://linear.app/nxdev/issue/NXC-4746/nxeslint-infers-projects-from-packagejson-files-outside-the-package

The same defect exists in @nx/oxlint and is being fixed on #36491, where it was originally found. This half is independent and ships today, so it is split out here.

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☁️ Nx Cloud last updated this comment at 2026-07-29 20:33:09 UTC

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