# jest-expect-jsonschema

A [Vitest](https://vitest.dev/) and [Jest](https://jestjs.io/) custom matcher for asserting valid [JSON Schema](https://json-schema.org/) objects.

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## Installation

```sh
npm install jest-expect-jsonschema --save-dev
```

## Usage

```ts
import { toBeValidJSONSchema } from 'jest-expect-jsonschema';
import { expect, test } from 'vitest';

expect.extend({ toBeValidJSONSchema });

test('should be valid JSON Schema', async () => {
  await expect({
    type: 'string',
  }).toBeValidJSONSchema();
});

test('should not be valid JSON Schema', () => {
  await expect({
    type: 'invalid-type',
  }).not.toBeValidJSONSchema();
});
```

The usage is nearly identical in Jest:

```ts
import { toBeValidJSONSchema } from 'jest-expect-jsonschema';

expect.extend({ toBeValidJSONSchema });

test('should be valid JSON Schema', () => {
  await expect({
    type: 'string',
  }).toBeValidJSONSchema();
});

test('should not valid JSON Schema', async () => {
  await expect({
    type: 'invalid-type',
  }).not.toBeValidJSONSchema();
});
```

If your project uses [`@jest/globals`](https://jestjs.io/docs/api#jestglobals) instead of Jest's injected globals, `toBeValidJSONSchema` and `toBeValidJSONSchemas` are typed there too:

```ts
import { expect, test } from '@jest/globals';
import { toBeValidJSONSchema } from 'jest-expect-jsonschema';

expect.extend({ toBeValidJSONSchema });

test('should be valid JSON Schema', async () => {
  await expect({
    type: 'string',
  }).toBeValidJSONSchema();
});
```

There is also a `toBeValidJSONSchemas` matcher that can be used with an array of objects:

```ts
import { toBeValidJSONSchemas } from 'jest-expect-jsonschema';
import { expect, test } from 'vitest';

expect.extend({ toBeValidJSONSchemas });

test('should be valid JSON Schemas', async () => {
  await expect([
    {
      type: 'string',
    },
    {
      type: 'object',
      required: ['name'],
      properties: {
        name: {
          type: 'string',
        },
      },
    },
  ]).toBeValidJSONSchemas();
});
```