doctrine

What is doctrine?

The doctrine npm package is a JSDoc type expression parser written in JavaScript. It allows developers to parse JSDoc comments and extract useful information and metadata about the code, which can be used for documentation generation, type checking, and other analysis purposes.

What are doctrine's main functionalities?

Parsing JSDoc comments

This feature allows you to parse JSDoc comments to extract information such as descriptions, parameters, and return types. The 'unwrap' option tells doctrine to strip the leading /**, trailing */, and any * that begins a line from the source text.

{"var doctrine = require('doctrine');\nvar ast = doctrine.parse('/**\n * This function adds two numbers together.\n * @param {number} a The first number.\n * @param {number} b The second number.\n * @return {number} The sum of the two numbers.\n */', { unwrap: true });\nconsole.log(ast);"}

Extracting type information

With this feature, you can extract type information from JSDoc comments. It parses the type expression and provides an abstract syntax tree (AST) representing the type information.

{"var doctrine = require('doctrine');\nvar ast = doctrine.parse('/** @type {Array.<string>} */', { unwrap: true });\nconsole.log(ast);"}

Parsing with recoverable errors

This feature allows parsing with recoverable errors, meaning that it will try to parse as much as possible without throwing an error immediately. This is useful for handling incomplete or incorrect JSDoc comments.

{"var doctrine = require('doctrine');\ntry {\n  var ast = doctrine.parse('/** @param {string} name */', { recoverable: true });\n  console.log(ast);\n} catch (error) {\n  console.error('Failed to parse:', error);\n}"}

Other packages similar to doctrine

comment-parser

The comment-parser package is another JSDoc comment parsing library. It focuses on extracting tags and descriptions from comments. Compared to doctrine, comment-parser may offer a different API and parsing strategy, potentially making it more suitable for certain use cases.

jsdoctypeparser

jsdoctypeparser is a parser for JSDoc type expressions. It is similar to doctrine in that it can parse type information from JSDoc comments, but it might have different parsing capabilities or API design, which could make it preferable depending on the developer's needs.

esdoc

esdoc is a documentation generator that parses JSDoc comments, but it also includes a full suite of features for generating comprehensive documentation for JavaScript code. While doctrine focuses solely on parsing, esdoc provides an end-to-end solution for documentation.

README

Doctrine

Doctrine is a JSDoc parser that parses documentation comments from JavaScript (you need to pass in the comment, not a whole JavaScript file).

Installation

You can install Doctrine using npm:

$ npm install doctrine --save-dev

Doctrine can also be used in web browsers using Browserify.

Usage

Require doctrine inside of your JavaScript:

var doctrine = require("doctrine");

parse()

The primary method is parse(), which accepts two arguments: the JSDoc comment to parse and an optional options object. The available options are:

• unwrap - set to true to delete the leading /**, any * that begins a line, and the trailing */ from the source text. Default: false.
• tags - an array of tags to return. When specified, Doctrine returns only tags in this array. For example, if tags is ["param"], then only @param tags will be returned. Default: null.
• recoverable - set to true to keep parsing even when syntax errors occur. Default: false.
• sloppy - set to true to allow optional parameters to be specified in brackets (@param {string} [foo]). Default: false.
• lineNumbers - set to true to add lineNumber to each node, specifying the line on which the node is found in the source. Default: false.
• range - set to true to add range to each node, specifying the start and end index of the node in the original comment. Default: false.

Here's a simple example:

var ast = doctrine.parse(
    [
        "/**",
        " * This function comment is parsed by doctrine",
        " * @param {{ok:String}} userName",
        "*/"
    ].join('\n'), { unwrap: true });

This example returns the following AST:

{
    "description": "This function comment is parsed by doctrine",
    "tags": [
        {
            "title": "param",
            "description": null,
            "type": {
                "type": "RecordType",
                "fields": [
                    {
                        "type": "FieldType",
                        "key": "ok",
                        "value": {
                            "type": "NameExpression",
                            "name": "String"
                        }
                    }
                ]
            },
            "name": "userName"
        }
    ]
}

See the demo page more detail.

Team

These folks keep the project moving and are resources for help:

• Nicholas C. Zakas (@nzakas) - project lead
• Yusuke Suzuki (@constellation) - reviewer

Contributing

Issues and pull requests will be triaged and responded to as quickly as possible. We operate under the ESLint Contributor Guidelines, so please be sure to read them before contributing. If you're not sure where to dig in, check out the issues.

Frequently Asked Questions

Can I pass a whole JavaScript file to Doctrine?

No. Doctrine can only parse JSDoc comments, so you'll need to pass just the JSDoc comment to Doctrine in order to work.

License

doctrine

Copyright JS Foundation and other contributors, https://js.foundation

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

esprima

some of functions is derived from esprima

Copyright (C) 2012, 2011 Ariya Hidayat (twitter: @ariyahidayat) and other contributors.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

closure-compiler

some of extensions is derived from closure-compiler

Apache License Version 2.0, January 2004 http://www.apache.org/licenses/

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