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Bug: ERR_UNSUPPORTED_ESM_URL_SCHEME on Windows when using codecept.conf.ts #5581
Description
What are you trying to achieve?
Run npx codeceptjs check to validate a TypeScript configuration file (codecept.conf.ts) on Windows.
What do you get instead?
The command fails with ERR_UNSUPPORTED_ESM_URL_SCHEME. CodeceptJS 4 transpiles the .ts config to a temp .js file and then calls import(tempFile) with a raw Windows absolute path (e.g. c:\Users\...\tempXXXX.js). The Node.js ESM loader on Windows only accepts file:// URLs — it treats c: as an unsupported URL scheme and throws.
Root cause
The issue is in lib/config.js line 245 (and 261):
configModule = await import(tempFile) // tempFile = "c:\Users\...\tempXXXX.js" on WindowsProposed fix — convert the path to a file:// URL before importing:
import { pathToFileURL } from 'url'
// ...
configModule = await import(pathToFileURL(tempFile).href)This issue only affects Windows. Unix absolute paths (
/home/...) are accepted by the ESM loader, while Windows drive-letter paths (c:\...) are not.
Console output
√ CONFIG Framework
Global functions are deprecated. Use `import { Helper, within, session } from "codeceptjs"` instead. Set `noGlobals: true` in config to disable globals.
Error: Only URLs with a scheme in: file, data, and node are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'c:'
at throwIfUnsupportedURLScheme (node:internal/modules/esm/load:241:11)
at defaultLoad (node:internal/modules/esm/load:132:3)
at ModuleLoader.load (node:internal/modules/esm/loader:724:12)
at ModuleLoader.loadAndTranslate (node:internal/modules/esm/loader:543:56)
at ModuleLoader.#createModuleJob (node:internal/modules/esm/loader:567:36)
at ModuleLoader.#getJobFromResolveResult (node:internal/modules/esm/loader:297:34)
at ModuleLoader.getModuleJobForImport (node:internal/modules/esm/loader:265:41)
at async ModuleLoader.import (node:internal/modules/esm/loader:605:23) {
code: 'ERR_UNSUPPORTED_ESM_URL_SCHEME'
}
Test source code
N/A — the error occurs during config loading, before any test runs.
Details
| Field | Value |
|---|---|
| CodeceptJS version | 4.0.2 |
| NodeJS Version | 20.20.2 |
| Operating System | Windows 11 Pro |
| playwright version | 1.39.0 |
Activity
kobenguyent commentedon Jun 3, 2026
@mmaaxi may you help check if #5595 resolves the windows issues?
kobenguyent commentedon Jun 8, 2026
supposed to be fixed by https://github.com/codeceptjs/CodeceptJS/releases/tag/4.0.4. Closing for now. Don't hesitate to report back if something still broken. Thanks!