https://github.com/ChristianMurphy/mdast-util-arbitrary

Generate arbitrary mdast with fast check
https://github.com/ChristianMurphy/mdast-util-arbitrary

markdown mdast mdast-util property-based-testing quickcheck testing unist

Last synced: about 2 months ago
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Generate arbitrary mdast with fast check

• Host: GitHub
• URL: https://github.com/ChristianMurphy/mdast-util-arbitrary
• Owner: ChristianMurphy
• License: mit
• Created: 2021-06-16T00:12:27.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-06-26T18:03:33.000Z (about 3 years ago)
• Last Synced: 2024-04-14T16:08:53.758Z (5 months ago)
• Topics: markdown, mdast, mdast-util, property-based-testing, quickcheck, testing, unist
• Language: TypeScript
• Homepage:
• Size: 129 KB
• Stars: 1
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# mdast-util-arbitrary

[![NPM Version](https://img.shields.io/npm/v/mdast-util-arbitrary)](https://www.npmjs.com/package/mdast-util-arbitrary)

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Generate arbitrary, random, and valid [`mdast`](https://github.com/syntax-tree/mdast) with [`fast-check`](https://github.com/dubzzz/fast-check), useful for [property testing](https://medium.com/criteo-engineering/introduction-to-property-based-testing-f5236229d237) [`mdast` utils](https://github.com/syntax-tree/mdast#list-of-utilities) and [`remark` plugins](https://github.com/remarkjs/remark/blob/main/doc/plugins.md#plugins).

## Install

```bash

npm install --save-dev mdast-util-arbitrary

```

## Usage

```ts

import { assert, property } from "fast-check";

import { commonmark } from "mdast-util-arbitrary";

assert(

  property(commonmark().Root, (mdast) => {

    // do something with mdast

  })

);

```

## API

This package exports a commonmark function which returns a dictionary of node types which can be generated (usually `Root` should be used starting node type)

`commonmark(options?: Options) => {[nodeType: string]: Arbitrary}`

### Options

#### `Options.includeData`

Whether to generate arbitrary [`data`](https://github.com/syntax-tree/unist#node) attributes for nodes. Default `false`.

#### `Options.rootNodeMaxChildren`

Limit the maximum number of child nodes the `Root` node can have. Default `100`.

## Example

Using [`uvu`](https://github.com/lukeed/uvu) to test [`mdast-util-to-markdown`](https://github.com/syntax-tree/mdast-util-to-markdown).

Checking three properties of `mdast-util-to-markdown`:

1. it does not throw an exception on valid markdown

2. it produces a string

3. it produces non-empty markdown text

Generating 100 mdast random mdast trees to see if the properties hold true.

```ts

import { test } from "uvu";

import toString from "mdast-util-to-markdown";

import { assert, property } from "fast-check";

import { commonmark } from "mdast-util-arbitrary";

test("arbitrary mdast can be stringified", () => {

  assert(

    property(commonmark().Root, (mdast) => {

      const markdown = toString(mdast);

      return typeof markdown === "string" && markdown.length > 1;

    }),

    { numRuns: 100 }

  );

});

test.run();

```