tsc-test

Testing TypeScript compilation (should succeed or should fail)

Basic usage

1. put tsconfig.json into test directory.

`"noEmit"` is recommended.

 ```json
 {
     "compilerOptions": {
         "target": "es5",
         "module": "commonjs",
         "noEmit": true,
         "strictNullChecks": true
     },
     "filesGlob": [
         "*.ts"
     ],
     "exclude": [
         "node_modules"
     ]
 }
 ```

1. put files to be tested into test directory.

```typescript
// should-succeed.ts

interface Foo { foo: string; }

export function test(foo: Foo) {
    console.log(foo.foo);
}
```

   When compilation errors should be occurred, write error code inline after 4 slashes(`////`).

```typescript
// should-fail-1.ts

interface Foo { foo: string; }

export function test(foo: Foo) {
    console.log(foo.bar);       //// TS2339
}
```

   You can write part of error message after error code. (with colon)

```typescript
// should-fail-2.ts

interface Foo { foo: string; }

export function test(foo: Foo) {
    console.log(foo.bar);       //// TS2339: Property 'bar' does not exist on
}
```

Or regular expression.

```typescript
// should-fail-3.ts (but this code is not wrong acturally ...)

interface Foo { foo: string; }

export function test(foo: Foo) {
    console.log(foo.foo);       //// TS2339: /property .* does not exist/i
}
```

1. run tsc-test command

```
$ tsc-test -p test/tsconfig.json
```

And you will get output like below:

```
OK: test/should-fail-1.ts
OK: test/should-fail-2.ts
NG: test/should-fail-3.ts
OK: test/should-succeed.ts

test/should-fail-3.ts:6
  expected: TS2339: /property .* does not exist/i
  bat was:  <no error>
```

Run with test runner

ava

// runner.ts

import test from "ava";
import { Tester, formatFailureMessage } from "tsc-test";

const tester = Tester.fromConfig("<path to tsconfig.json>");
tester.sources.forEach(fileName => {
    test(fileName, t => {
        const failures = tester.test(fileName);
        if (failures.length > 0) {
            t.fail(formatFailureMessage(...failures));
        }
    })
});

License

MIT