biome correctness/noGlobalDirnameFilename: fix changes program behavior

Hypothesis Nemotron 3 Super predicted to fire fired 1×

arguments object, function.length, default parameters, rest parameters

Program

Output

(no stdout)
ReferenceError: __dirname is not defined in ES module scope

undefined

Judge Nemotron 3 Ultra advisory program-bug · low

The program runs as an ES module where __dirname is not defined, causing a ReferenceError before the fix. The rewrite replaces it with import.meta.dirname, which is the correct ES module equivalent, so the behavioral change is due to the module system environment, not a bug in the fix itself.

Explanation Nemotron 3 Super unverified

The original program uses `__dirname`, which is undefined in ES modules, causing a ReferenceError that exits with code 1; the rewritten version substitutes `import.meta.dirname`, which resolves to the directory of the current module file, allowing the function to return a string instead of throwing, so the program prints that path and exits successfully. This changes both output and exit status, altering observable behavior.

Reproduce

file

prog.js (the before program)

minimized program

r1-p003.js

evidence sheet

r1-p003.md

regression fixture

r1-p003.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 · correctness noGlobalDirnameFilename default parameter · import meta dirname replacement function argument · ES module __dirname undefined error fix

• related biomejs/biome/issues/5778 same rule category (correctness/no*Global) but different construct (process global vs __dirname/__filename)
• related biomejs/biome/issues/9061 same rule category (correctness/no*Global) but different construct (process.env vs __dirname/__filename)

Details

program

Function using __dirname in default parameter

hazard

arguments object, function.length, default parameters, rest parameters

oracle

stdout before: stdout after: undefined exit 1 → 0 stderr before: ReferenceError: __dirname is not defined in ES module scope stderr after: (none)

run

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

--- orig.js	2026-10-17 16:16:39.716046238 -0400
+++ fixed.js	2026-10-17 16:16:40.007042667 -0400
@@ -1,5 +1,5 @@
 // Hazard 3
-function f(dir = __dirname) {
+function f(dir = import.meta.dirname) {
   return dir.length;
 }
 console.log(f());

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/")) {}
 ```