extract-comments

Uses esprima to extract line and block comments from a string of JavaScript. Also optionally parses code context (the next line of code after a comment).

Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your ❤️ and support.

Install

Install with npm:

$ npm install --save extract-comments

Usage

var extract = require('extract-comments');
 
// pass a string of JavaScript
extract(string);

Example

var str = '/**\n * this is\n *\n * a comment\n*/\n\n\nvar foo = "bar";\n';
var comments = extract(str);
console.log(comments);
 
[{
  type: 'block',
  raw: '/**\n * this is\n *\n * a comment\n*/',
  value: 'this is\na comment',
  loc: { start: { line: 1, column: 0 }, end: { line: 5, column: 33 } },
  code:
   { line: 7,
     loc: { start: { line: 7, column: 36 }, end: { line: 7, column: 52 } },
     value: 'var foo = "bar";' }

Extractors

By default, esprima is used for extracting comments. This can easily be changed by passing a function to options.extractor.

The easy way

Use a published module, such as:

Example:

extract(str, {extractor: require('babel-extract-comments')});

If you create a compatible extractor, feel free to do pr or create an issue to add it to the readme!

Roll your own

extract(str, {
  extractor: function(str) {
    // must return an array of tokens with:
    // - type: 'Block', 'CommentBlock', 'Line' or 'CommentLine'
    // - value: the comment inner string
    // - loc: with `start` and `end` line and column
    // example:
    return [
      { 
        type: 'Block',
        {start: { line: 1, column: 0 },
          end: { line: 5, column: 33 }},
        value: ' this is a comment string '
      }
    ];
  }
});

API

extract

Extract comments from the given string.

Params

string {String}
options {Object}: Pass first: true to return after the first comment is found.
tranformFn {Function}: (optional) Tranform function to modify each comment
returns {Array}: Returns an array of comment objects

Example

const extract = require('extract-comments');
console.log(extract(string, options));

.block

Extract block comments from the given string.

Params

string {String}
options {Object}: Pass first: true to return after the first comment is found.
returns {String}

Example

console.log(extract.block(string, options));

.line

Extract line comments from the given string.

Params

string {String}
options {Object}: Pass first: true to return after the first comment is found.
returns {String}

Example

console.log(extract.line(string, options));

.first

Extract the first comment from the given string.

Params

string {String}
options {Object}: Pass first: true to return after the first comment is found.
returns {String}

Example

console.log(extract.first(string, options));

Release history

v0.10.0

Parsing is now handled by esprima, so only JavaScript can be parsed. I'm working on parsers for other languages and will cross-link those here when they're pushed up.
Breaking change: since parsing is now done by esprima, on both the line and block comment objects, the loc.start.pos and loc.end.pos properties have been renamed to loc.start.column and loc.end.column.

v0.9.0

Breaking change: lines property was removed from Block comments, since this can easily be done by splitting value

About

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Running Tests

Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:

$ npm install && npm test

Building docs

(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)

To generate the readme, run the following command:

$ npm install -g verbose/verb#dev verb-generate-readme && verb

Related projects

You might also be interested in these projects:

babel-extract-comments: Uses babel (babylon) to extract JavaScript code comments from a JavaScript string or file. | homepage
code-context: Parse a string of javascript to determine the context for functions, variables and comments based… more | homepage
espree-extract-comments: Uses espree to extract JavaScript code comments from a string. Returns an array of comment… more | homepage
esprima-extract-comments: Extract code comments from string or from a glob of files using esprima. | homepage
parse-comments: Parse code comments from JavaScript or any language that uses the same format. | homepage

Contributors

Commits	Contributor
93	jonschlinkert
3	cazzer
1	architectcodes

Author

Jon Schlinkert

License

This file was generated by verb-generate-readme, v0.6.0, on February 12, 2018.

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