Tests failed to load after upgrading to 5.1.1

[mike-4040]

Environment

1. Node 20.11.1

2. Dependencies

    "chai": "^5.1.1",
    "mocha": "^10.4.0",
    "ts-node": "^10.9.2",
    "typescript": "^5.4.5",

3. Tests configuration

• .mocharc file

# .mocharc
{
 "$schema": "https://json.schemastore.org/mocharc",
 "reporter": "spec",
 "require": ["ts-node/register", "src/testUtils/global-mocha-fixture.ts"],
}

• test file

# ./src/sample.test.ts
import { expect } from 'chai';

describe('Simple Test', () => {
  it('should return true', () => {
    expect(true).to.be.true;
  });
});

• running test npx ./node_modules/mocha/bin/mocha.js ./src/sample.test.ts

Issue

After upgrading chai 4.4.1 => 5.1.1 consistently getting Error:

 Exception during run: TypeError: Unknown file extension ".ts" for ./src/sample.test.ts
    at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:160:9)
    at defaultGetFormat (node:internal/modules/esm/get_format:203:36)
    at defaultLoad (node:internal/modules/esm/load:143:22)
    at async ModuleLoader.load (node:internal/modules/esm/loader:409:7)
    at async ModuleLoader.moduleProvider (node:internal/modules/esm/loader:291:45)
    at async link (node:internal/modules/esm/module_job:76:21) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

[43081j]

you need to set loader for ESM in mocha:

https://gist.github.com/43081j/78ce1392abb5043b02a29355006880a5#file-mocharc-json

afaik, you can also have both loader and require set (in case somehow you have a mixture of cjs/esm)