biome correctness/noGlobalDirnameFilename: fix changes program behavior

Hypothesis Nemotron 3 Super predicted to fire fired 1×

If __dirname access throws (hypothetical), the fix removes the try/catch scope.

Program

Output

threw: true

threw: false

Judge Nemotron 3 Ultra advisory program-bug · low

The program runs in a CommonJS environment where __dirname exists but import.meta.dirname does not, so the original code catches a ReferenceError and logs threw: true. After the fix, the rewritten code uses import.meta.dirname which throws in CommonJS, but the oracle shows threw: false, indicating the execution environment changed or the test setup differs. The rule's fix is only correct for ES modules; applying it in CommonJS changes behavior due to module system differences, not a flaw in the rule itself.

Explanation Nemotron 3 Super unverified

The original code uses `__dirname`, which in CommonJS resolves to the directory of the current file; if unavailable (e.g., in certain module contexts), it throws a ReferenceError, caught and setting `threw` to true. The replacement `import.meta.dirname` is an ES module property that is only available when the code is parsed as an ES module; in environments where it is undefined or inaccessible, accessing it may still throw—but here, the environment likely supports it without error, so no exception occurs, `threw` remains false, and the output changes. The rewrite assumes semantic equivalence, but `__dirname` and `import.meta.dirname` differ in availability and scoping across module systems, making the substitution unsafe in this context.

Reproduce

file

prog.js (the before program)

minimized program

r2-p002.js

evidence sheet

r2-p002.md

regression fixture

r2-p002.js the minimized program with a header stating the observed change, for the tool's test suite

node prog.js
bunx @biomejs/biome lint --only=correctness/noGlobalDirnameFilename --write prog.js
node prog.js

Upstream search GitHub issues Tavily Nemotron 3 Super + Ultra

noGlobalDirnameFilename fix · __dirname usage in try block · import.meta.dirname replacement pattern · noGlobalDirnameFilename rule enforcement

• related biomejs/biome/pull/8922 same rule (noGlobalDirnameFilename) but different defect (revamp for false negatives vs fix-changes-behavior on try/catch)
• related biomejs/biome/issues/8829 same rule (noGlobalDirnameFilename) but different defect (false negatives vs fix-changes-behavior on try/catch)

Details

program

Exception during evaluation

hazard

If __dirname access throws (hypothetical), the fix removes the try/catch scope.

oracle

stdout before: threw: true stdout after: threw: false

run

2026-10-17T20-16-26-722Z-l85y-biome-correctness_noGlobalDirnameFilename

--- orig.js	2026-10-17 16:16:49.500927738 -0400
+++ fixed.js	2026-10-17 16:16:49.762924605 -0400
@@ -1,6 +1,6 @@
 let threw = false;
 try {
-  const d = __dirname;
+  const d = import.meta.dirname;
   if (d === undefined) throw new Error('unexpected');
 } catch (e) {
   threw = true;

Summary

- Name: noGlobalDirnameFilename
- Fix: safe
- Default severity: info
- Available from version: 2.0.0
- Diagnostic category: lint/correctness/noGlobalDirnameFilename


Description

 Disallow the use of `__dirname` and `__filename` in the global scope.

 They are [not available in ES modules](https://nodejs.org/api/esm.html#esm_no_filename_or_dirname).
 Starting with Node.js 20.11, `import.meta.dirname` and `import.meta.filename` have been introduced in ES modules, providing identical functionality to `__dirname` and `__filename` in CommonJS (CJS).

Examples

Invalid

 ```js,expect_diagnostic
 const dirname = __dirname;
 ```

 ```js,expect_diagnostic
 const filename = __filename;
 ```

 ``` js,expect_diagnostic
 const foo = { __filename }
 ```

 ```js,expect_diagnostic
 if (__dirname.startsWith("/project/src/")) {}
 ```

Valid

 ```js
 const dirname = import.meta.dirname
 const filename = import.meta.filename
 const foo = {__filename: import.meta.filename };
 if (import.meta.dirname.startsWith("/project/src/")) {}
 ```