forked from M3-Academy/challenge-algorithms-v2.0
109 lines
2.8 KiB
Markdown
109 lines
2.8 KiB
Markdown
# jest-docblock
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`jest-docblock` is a package that can extract and parse a specially-formatted comment called a "docblock" at the top of a file.
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A docblock looks like this:
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```js
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/**
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* Stuff goes here!
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*/
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```
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Docblocks can contain pragmas, which are words prefixed by `@`:
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```js
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/**
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* Pragma incoming!
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*
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* @flow
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*/
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```
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Pragmas can also take arguments:
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```js
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/**
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* Check this out:
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*
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* @myPragma it is so cool
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*/
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```
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`jest-docblock` can:
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- extract the docblock from some code as a string
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- parse a docblock string's pragmas into an object
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- print an object and some comments back to a string
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## Installation
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```sh
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# with yarn
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$ yarn add jest-docblock
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# with npm
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$ npm install jest-docblock
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```
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## Usage
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```js
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const code = `
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/**
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* Everything is awesome!
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*
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* @everything is:awesome
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* @flow
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*/
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export const everything = Object.create(null);
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export default function isAwesome(something) {
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return something === everything;
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}
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`;
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const {
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extract,
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strip,
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parse,
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parseWithComments,
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print,
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} = require('jest-docblock');
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const docblock = extract(code);
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console.log(docblock); // "/**\n * Everything is awesome!\n * \n * @everything is:awesome\n * @flow\n */"
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const stripped = strip(code);
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console.log(stripped); // "export const everything = Object.create(null);\n export default function isAwesome(something) {\n return something === everything;\n }"
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const pragmas = parse(docblock);
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console.log(pragmas); // { everything: "is:awesome", flow: "" }
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const parsed = parseWithComments(docblock);
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console.log(parsed); // { comments: "Everything is awesome!", pragmas: { everything: "is:awesome", flow: "" } }
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console.log(print({pragmas, comments: 'hi!'})); // /**\n * hi!\n *\n * @everything is:awesome\n * @flow\n */;
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```
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## API Documentation
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### `extract(contents: string): string`
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Extracts a docblock from some file contents. Returns the docblock contained in `contents`. If `contents` did not contain a docblock, it will return the empty string (`""`).
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### `strip(contents: string): string`
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Strips the top docblock from a file and return the result. If a file does not have a docblock at the top, then return the file unchanged.
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### `parse(docblock: string): {[key: string]: string | string[] }`
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Parses the pragmas in a docblock string into an object whose keys are the pragma tags and whose values are the arguments to those pragmas.
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### `parseWithComments(docblock: string): { comments: string, pragmas: {[key: string]: string | string[]} }`
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Similar to `parse` except this method also returns the comments from the docblock. Useful when used with `print()`.
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### `print({ comments?: string, pragmas?: {[key: string]: string | string[]} }): string`
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Prints an object of key-value pairs back into a docblock. If `comments` are provided, they will be positioned on the top of the docblock.
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