221 lines
7.6 KiB
Markdown
Raw Normal View History

# comment-parser
`comment-parser` is a library helping to handle Generic JSDoc-style comments. It is
- **language-agnostic** no semantics enforced. You decide what tags are and what they mean. And it can be used with any language supporting `/** */` source comments.
- **no dependencies** it is compact and environment-agnostic, can be run on both the server and browser sides
- **highly customizable** with a little code you can deeply customize how comments are parsed
- **bidirectional** - you can write comment blocks back to the source after updating or formatting
- **strictly typed** - comes with generated `d.ts` data definitions since written in TypeScript
```sh
npm install comment-parser
```
> 💡 Check out the [Playground](https://syavorsky.github.io/comment-parser)
> 💡 Previous version lives in [0.x](https://github.com/syavorsky/comment-parser/tree/0.x) branch
Lib mainly provides two pieces [Parser](#Parser) and [Stringifier](#Stringifier).
## Parser
Let's go over string parsing:
```js
const { parse } = require('comment-parser/lib')
const source = `
/**
* Description may go
* over few lines followed by @tags
* @param {string} name the name parameter
* @param {any} value the value of any type
*/`
const parsed = parse(source)
```
Lib source code is written in TypeScript and all data shapes are conveniently available for your IDE of choice. All types described below can be found in [primitives.ts](src/primitives.ts)
The input source is first parsed into lines, then lines split into tokens, and finally, tokens are processed into blocks of tags
### Block
```js
/**
* Description may go
* over multiple lines followed by @tags
* @param {string} name the name parameter
* @param {any} value the value parameter
*/
```
### Description
```js
/**
* Description may go
* over multiple lines followed by @tags
```
### Tags
```js
* @param {string} name the name parameter
```
```js
* @param {any} value the value parameter
*/
```
### Tokens
```
|line|start|delimiter|postDelimiter|tag |postTag|name |postName|type |postType|description |end|
|----|-----|---------|-------------|------|-------|-----|--------|--------|--------|--------------------------------|---|
| 0|{2} |/** | | | | | | | | | |
| 1|{3} |* |{1} | | | | | | |Description may go | |
| 2|{3} |* |{1} | | | | | | |over few lines followed by @tags| |
| 3|{3} |* |{1} |@param|{1} |name |{1} |{string}|{1} |the name parameter | |
| 4|{3} |* |{1} |@param|{1} |value|{1} |{any} |{1} |the value of any type | |
| 5|{3} | | | | | | | | | |*/ |
```
### Result
The result is an array of Block objects, see the full output on the [playground](https://syavorsky.github.io/comment-parser)
```js
[{
// uppper text of the comment, overall block description
description: 'Description may go over multiple lines followed by @tags',
// list of block tags: @param, @param
tags: [{
// tokens.tag without "@"
tag: 'param',
// unwrapped tokens.name
name: 'name',
// unwrapped tokens.type
type: 'string',
// true, if tokens.name is [optional]
optional: false,
// default value if optional [name=default] has one
default: undefined,
// tokens.description assembled from a siongle or multiple lines
description: 'the name parameter',
// problems occured while parsing this tag section, subset of ../problems array
problems: [],
// source lines processed for extracting this tag, "slice" of the ../source item reference
source: [ ... ],
}, ... ],
// source is an array of `Line` items having the source
// line number and `Tokens` that can be assembled back into
// the line string preserving original formatting
source: [{
// source line number
number: 1,
// source line string
source: "/**",
// source line tokens
tokens: {
// indentation
start: "",
// delimiter, either '/**', '*/', '*', or ''. Mid lines may have no delimiters
delimiter: "/**",
// space between delimiter and tag
postDelimiter: "",
// tag starting with "@"
tag: "",
// space between tag and type
postTag: "",
// name with no whitespaces or "multiple words" wrapped into quotes. May occure in [name] and [name=default] forms
name: "",
// space between name and type
postName: "",
// type is has to be {wrapped} into curlies otherwise will be omitted
type: "",
// space between type and description
postType: "",
// description is basicaly rest of the line
description: "",
// closing */ marker if present
end: ""
}
}, ... ],
// problems occured while parsing the block
problems: [],
}];
```
While `.source[].tokens` are not providing readable annotation information, they are essential for tracing data origins and assembling string blocks with `stringify`
### options
```ts
interface Options {
// start count for source line numbers
startLine: number;
// escaping chars sequence marking wrapped content literal for the parser
fence: string;
// block and comment description compaction strategy
spacing: 'compact' | 'preserve';
// tokenizer functions extracting name, type, and description out of tag, see Tokenizer
tokenizers: Tokenizer[];
}
```
examples
- [default config](https://syavorsky.github.io/comment-parser/#parse-defaults)
- [line numbers control](https://syavorsky.github.io/comment-parser/#parse-line-numbering)
- [description spacing](https://syavorsky.github.io/comment-parser/#parse-spacing)
- [escaping](https://syavorsky.github.io/comment-parser/#parse-escaping)
- [explore the origin source](https://syavorsky.github.io/comment-parser/#parse-source-exploration)
[suggest more examples](https://github.com/syavorsky/comment-parser/issues/new?title=example+suggestion%3A+...&labels=example,parser)
## Stringifier
The stringifier is an important piece used by other tools updating the source code. It goes over `Block.source[].tokens` items and assembles them back to the string. It might be used with various transforms applied before stringifying.
```js
const { parse, stringify, transforms: {flow, align, indent} } = require('comment-parser');
const source = `
/**
* Description may go
* over multiple lines followed by @tags
*
* @my-tag {my.type} my-name description line 1
description line 2
* description line 3
*/`;
const parsed = parse(source);
const transform = flow(align(), indent(0))
console.log(stringify(transform(parsed[0])));
```
### Result
```js
/**
* Description may go
* over multiple lines followed by @tags
*
* @my-tag {my.type} my-name description line 1
description line 2
* description line 3
*/
```
examples
- [format comments](https://syavorsky.github.io/comment-parser/#stringify-formatting)
[suggest more examples](https://github.com/syavorsky/comment-parser/issues/new?title=example+suggestion%3A+...&labels=example,stringifier)
## Migrating from 0.x version
Code of pre-1.0 version is forked into [0.x](https://github.com/syavorsky/comment-parser/tree/0.x) and will phase out eventually. Please file the issue if you find some previously existing functionality can't be achieved with 1.x API. Check out [migration notes](migrate-1.0.md).