exclude type checking for files which matches with `exclude` option from tsconfig

[changchangge]

TypeScript Version:4.1.3
ts-jest Version:26.4.4

Code

tsconfig.json

{
  "compilerOptions": {
    "sourceMap": false,
    "module": "commonjs", 
    "noImplicitAny": true, 
    "removeComments": false,
    "moduleResolution":"node",
    "baseUrl": ".",  
    "target": "es6", 
    "outDir": "./lib",
    "declaration": true,
    "strict": true,
  },
  "include": ["src"],
  "exclude": ["node_modules","tests"]
}

jest.config.js

module.exports = {
  roots: ['<rootDir>/tests'],
  globals: {
    'ts-jest': {
      tsconfig: 'tsconfig.json',
    },
  },
  transform: {
    '^.+\\.ts?$': 'ts-jest',
  },
  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|tsx?)$',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
  testEnvironment: 'node',
  collectCoverageFrom: ['<rootDir>/src/**/*'],
  coveragePathIgnorePatterns: ['<rootDir>/node_modules', '<rootDir>/tests'],
  verbose: true,
};

When I run tsc, it is ok. But if I run jest to test，it is failed.

Expected behavior:

Avoid and exclude tests ts files.

Actual behavior:

It check ts files in the tests folder which has been excluded.

Workaround:

But if a restart VS then i will see the same behavior.

error:

● Test suite failed to run

tests/tag2.test.ts:5:22 - error TS7006: Parameter 'state' implicitly has an 'any' type.

Here is my project:
https://github.com/changchangge/simple-redux/tree/tag2

I hope that someone can help me , thanks!

[ahnpnl]

Hi, for ts-jest, we always do type checking for all .ts files by default regardless what is defined in exclude and it has been like that. Workaround is to use https://kulshekhar.github.io/ts-jest/docs/options/diagnostics

I think it does make sense to follow the real purpose of those config options.

I will convert this to feature request instead.

[ahnpnl]

I've checked. Actually we can't use exclude for type checking. exclude option is tsconfig does 3 things:

• Exclude files from TypeScript Program for module resolution
• Exclude files from compiling
• Exclude files from type checking

ts-jest makes use of TypeScript Program to compile codes and type checking. This process is an incremental on-demand process, it's not the same like normal behavior of tsc. ts-jest behavior is partially similar to tsc to be able to work with Jest.

Therefore, it is not possible to use exclude to exclude files from type checking because that will break compilation process.

I will close this issue as we use diagnostics option as alternative way.