Windows file path parsed incorrectly when running dart run coverage on Windows + Node.js + dart2wasm

[elliotwutingfeng]

Details

Dart SDK: 3.9.4

OS: Windows Server 2025 (GitHub Actions GitHub-hosted runner)

Platform: Node.js 24.9.0

Compiler: Dart2Wasm

package:test version: 1.26.3

package:coverage version: 1.15.0

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I ran dart run coverage on this basic sandbox repository with a simple "hello-world" style test. https://github.com/elliotwutingfeng/dart_sandbox_02102025

Note: I'm posting here as although the command was coverage, the error logs reference package:test.

Command

dart run coverage:test_with_coverage --function-coverage --branch-coverage

Error log (link)

❌ [Node.js, Dart2Wasm] loading test\dart_sandbox_02102025_test.dart (failed)
  Generated wasm module 'C:\Users\runneradmin\AppData\Local\Temp\dart_test_296a0ef9\test_6d7be5ce\dart_sandbox_02102025_test.dart.node_test.dart.wasm.wasm', and JS init file 'C:\Users\runneradmin\AppData\Local\Temp\dart_test_296a0ef9\test_6d7be5ce\dart_sandbox_02102025_test.dart.node_test.dart.wasm.mjs'.
  
  node:internal/process/promises:394
      triggerUncaughtException(err, true /* fromPromise */);
      ^
  
  [Error: ENOENT: no such file or directory, open 'C:Users
  unneradminAppDataLocalTempdart_test_296a0ef9	est_6d7be5cedart_sandbox_02102025_test.dart.node_test.dart.wasm.wasm'] {
    errno: -4058,
    code: 'ENOENT',
    syscall: 'open',
    path: 'C:Users\runneradminAppDataLocalTempdart_test_296a0ef9\test_6d7be5cedart_sandbox_02102025_test.dart.node_test.dart.wasm.wasm'
  }
  
  Node.js v24.9.0
  Failed to load "test\dart_sandbox_02102025_test.dart": Node exited before connecting to the test channel.
  package:test/src/runner/node/platform.dart 123:9    NodePlatform._loadChannel
  ===== asynchronous gap ===========================
  package:test/src/runner/node/platform.dart 86:9     NodePlatform.load
  ===== asynchronous gap ===========================
  package:test_core/src/runner/loader.dart 219:27     Loader.loadFile.<fn>
  ===== asynchronous gap ===========================
  package:test_core/src/runner/load_suite.dart 96:19  new LoadSuite.<fn>.<fn>

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It appears that the backslashes are interpreted by Node.js as escape sequences.