Bug: ERR_UNSUPPORTED_ESM_URL_SCHEME on Windows when using codecept.conf.ts

[mmaaxi]

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 Windows

Proposed 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