@js.properties/parser v0.2.1

@js.properties/parser

DEPRECATED @js.properties/parser has been renamed to @js.properties/properties

JavaScript .properties parser

This is a parser written in JavaScript and PEG.js for Java .properties file format, following the syntax defined in Java API Specification.

The parser can return parsed properties object (parseToProperites) in a flat structure or a hierarchical namespaced structure, or return raw parsing result (parseToEntries) as an array of entry objects which have key, element, original, eol and location as keys.

As to the raw parsing result:

• Each logical line of input .properties file is parsed into an object, with the original logical line, eol info, and/or line location info optionally kept;
• Properties with duplicate keys are kept in the raw output so that one can build high-level applications reporting them;
• Blank and comment lines can be kept as well so that there is no info loss of the original file after parsing. This could be useful for something like .properties IDE.

Installation

npm install --save @js.properties/parser
# or
yarn add @js.properties/parser

Quick Example

example.properties:

# Comment here
hello = world

foo : bar

demo.js (Node.js):

const fs = require('fs');
const PropertiesParser = require('@js.properties/parser');

const input = fs.readFileSync('example.properties', 'utf8');
const options = {   // options is optional
  all: true,        // Include empty and blank lines
  original: true,   // Include original logical line in output
  eol: true,        // Include eol (end of line) in output
  location: true,   // Include location info in output
};
let output = PropertiesParser.parseToEntries(input, options);

demo.html (Browser):

<!-- @js.properties/parser is available as an UMD module. -->
<script src="properties-parser.min.js"></script>
<script>
// Input can be entered manually or read via FileReader API
var output = PropertiesParser.parseToEntries('...');
</script>

Output with all options off:

[
  { "key": "hello", "element": "world" },
  { "key": "foo", "element": "bar" }
]

Output with all options on:

[
  {
    "key": null, "element": null,
    "original": "# Comment here", "eol": "\n",
    "location": {
      "start": { "offset":  0, "line": 1, "column":  1 },
      "end":   { "offset": 14, "line": 1, "column": 15 } }
  },
  {
    "key": "hello", "element": "world",
    "original": "hello = world", "eol": "\n",
    "location": {
      "start": { "offset": 15, "line": 2, "column":  1 },
      "end":   { "offset": 28, "line": 2, "column": 14 } }
  },
  {
    "key": null, "element": null,
    "original": "", "eol": "\n",
    "location": {
      "start": { "offset": 29, "line": 3, "column":  1 },
      "end":   { "offset": 29, "line": 3, "column":  1 } }
  },
  {
    "key": "foo", "element": "bar",
    "original": "foo : bar", "eol": "\n",
    "location": {
      "start": { "offset": 30, "line": 4, "column":  1 },
      "end":   { "offset": 39, "line": 4, "column": 10 } }
  }
]

There is also a method parseToProperties(input) which generates output like:

{
  "hello": "world",
  "foo": "bar"
}

API

Method: parseToProperties(string , options )

Object: options

All options default to false.

true and { '': true } can be used as a shortcut to turn on all options. { '': true, namespace: false } can be used to turn on all options except for those listed explicitly.

Returns: object

Throws: SyntaxError Invalid Unicode escape sequence

Method: parseToEntries(string , options )

Object: options

All options default to false.

true and { '': true } can be used as a shortcut to turn on all options. { '': true, location: false } can be used to turn on all options except for those listed explicitly.

Returns: Array<PropertyEntry>

Object: PropertyEntry

Note: key and element will be null for blank and comment lines.

Note: original is always a string, in the case of blank line, it's an empty string.

Note: eol will be null if this is the last line and contains no final eol.

* A logical line may spread across several natural lines if line continuation is involved.

Object: Location

{ start: Position, end: Position }

Object: Position

{ offset: number, line: number, column: number }

Development

Code Structure

@js.properties/parser
├── src            // Originally authored source code.
│   └── *.pegjs.js //   This one is an exception, generated by pegjs.
├── types          // TypeScript declaration files
├── lib            // Generated by babel, spread in multiple files,
│                  //   in CommonJS format, for Node.js use.
├── dist           // Generated by webpack into a single file,
│                  //   in UMD format, for browser and Node.js.
└── test
    ├── data       // Test data, *.properties are authored
    │              //   and *.json are generated and compared
    ├── java       // Reference implementation in Java
    └── js         // Test code in JavaScript

Build

yarn run prepare
# or
npm run prepare

Test

yarn test
# or
npm test

Update expected test output

yarn run test:snapshot
# or
npm run test:snapshot

Lint

yarn run lint
# or
npm run lint

LICENSE

The MIT License. See LICENSE file.