type-tester


A tester to check expected type errors.

🏁 Goal

This package provides utility to verify that the type you have written stricter reports expected type errors, for TypeScript.

💿 Installation

Use [npm] or a compatible tool to install this package.

``
npm install type-tester typescript
`

- Requires Node.js >=6.0.0.

📖 Usage

1. Write fixture files.
2. Write test files.
3. Run test files with test runner such as [mocha].

$3

The fixture file should include the situation of type error.
You must add directive comments such as // @expected 2345 for each line of expected errors.
The number is the error code of TypeScript.

For example: test/fixtures/event-target-shim/fixture.ts

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The test file should execute TypeTester#verify() method with the path to the fixture files and compiler options.

For example: test/example.ts

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Because the TypeTester#verify() method defines test cases with describe / it global functions, you must run it with test runners.

For example:

`
mocha test/example.ts --require ts-node/register

this test runs the type tester merely.
fixture.ts
√ should have an error TS2345 at L98.
√ should have an error TS2345 at L101.
√ should have an error TS7006 at L102.
√ should have an error TS2345 at L105.
√ should have an error TS7006 at L106.
√ should have an error TS2322 at L108.
√ should have an error TS2322 at L109.
√ should have an error TS2345 at L152.

8 passing (11ms)
`

📚 API References

$3

The class to verify expected type errors.

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#### Parameters

Name | Description
:----|:-----------
ts | API to use type checking.
options.describe | Optional. Function to declare test suites. Use global.describe by default.
options.it | Optional. Function to declare test cases. Use global.it by default.

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Verify the given fixture files.

#### Parameters

Name | Description
:----|:-----------
fixtureFiles | Path to fixture files.
compilerOptions | Compiler options to verify the fixture files.

📰 Release notes

- https://github.com/mysticatea/type-tester/releases

❤️ Contributing

Contribution is welcome!

Please use GitHub issues and pull requests.

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- npm run build generates files into dist directory.
- npm run clean removes temporary files.
- npm run coverage opens the coverage report the last npm test command generated.
- npm run lint runs ESLint.
- npm test runs tests.
- npm run watch` runs tests on each file edits.

[mocha]: https://mochajs.org/
[npm]: https://www.npmjs.com/