node_modules/jstransform/node_modules/source-map/README.md

Source Map

This is a library to generate and consume the source map format described here.

This library is written in the Asynchronous Module Definition format, and works in the following environments:

Node

$ npm install source-map

Building from Source (for everywhere else)

Install Node and then run

$ git clone https://fitzgen@github.com/mozilla/source-map.git
$ cd source-map
$ npm link .

Next, run

$ node Makefile.dryice.js

This should spew a bunch of stuff to stdout, and create the following files:

Examples

Consuming a source map

var rawSourceMap = {
  version: 3,
  file: 'min.js',
  names: ['bar', 'baz', 'n'],
  sources: ['one.js', 'two.js'],
  sourceRoot: 'http://example.com/www/js/',
  mappings: 'CAAC,IAAI,IAAM,SAAUA,GAClB,OAAOC,IAAID;CCDb,IAAI,IAAM,SAAUE,GAClB,OAAOA'
};

var smc = new SourceMapConsumer(rawSourceMap);

console.log(smc.sources);
// [ 'http://example.com/www/js/one.js',
//   'http://example.com/www/js/two.js' ]

console.log(smc.originalPositionFor({
  line: 2,
  column: 28
}));
// { source: 'http://example.com/www/js/two.js',
//   line: 2,
//   column: 10,
//   name: 'n' }

console.log(smc.generatedPositionFor({
  source: 'http://example.com/www/js/two.js',
  line: 2,
  column: 10
}));
// { line: 2, column: 28 }

smc.eachMapping(function (m) {
  // ...
});

Generating a source map

In depth guide: Compiling to JavaScript, and Debugging with Source Maps

With SourceNode (high level API)

function compile(ast) {
  switch (ast.type) {
  case 'BinaryExpression':
    return new SourceNode(
      ast.location.line,
      ast.location.column,
      ast.location.source,
      [compile(ast.left), " + ", compile(ast.right)]
    );
  case 'Literal':
    return new SourceNode(
      ast.location.line,
      ast.location.column,
      ast.location.source,
      String(ast.value)
    );
  // ...
  default:
    throw new Error("Bad AST");
  }
}

var ast = parse("40 + 2", "add.js");
console.log(compile(ast).toStringWithSourceMap({
  file: 'add.js'
}));
// { code: '40 + 2',
//   map: [object SourceMapGenerator] }

With SourceMapGenerator (low level API)

var map = new SourceMapGenerator({
  file: "source-mapped.js"
});

map.addMapping({
  generated: {
    line: 10,
    column: 35
  },
  source: "foo.js",
  original: {
    line: 33,
    column: 2
  },
  name: "christopher"
});

console.log(map.toString());
// '{"version":3,"file":"source-mapped.js","sources":["foo.js"],"names":["christopher"],"mappings":";;;;;;;;;mCAgCEA"}'

API

Get a reference to the module:

// NodeJS
var sourceMap = require('source-map');

// Browser builds
var sourceMap = window.sourceMap;

// Inside Firefox
let sourceMap = {};
Components.utils.import('resource:///modules/devtools/SourceMap.jsm', sourceMap);

SourceMapConsumer

A SourceMapConsumer instance represents a parsed source map which we can query for information about the original file positions by giving it a file position in the generated source.

new SourceMapConsumer(rawSourceMap)

The only parameter is the raw source map (either as a string which can be JSON.parse'd, or an object). According to the spec, source maps have the following attributes:

SourceMapConsumer.prototype.computeColumnSpans()

Compute the last column for each generated mapping. The last column is inclusive.

SourceMapConsumer.prototype.originalPositionFor(generatedPosition)

Returns the original source, line, and column information for the generated source's line and column positions provided. The only argument is an object with the following properties:

and an object is returned with the following properties:

SourceMapConsumer.prototype.generatedPositionFor(originalPosition)

Returns the generated line and column information for the original source, line, and column positions provided. The only argument is an object with the following properties:

and an object is returned with the following properties:

SourceMapConsumer.prototype.allGeneratedPositionsFor(originalPosition)

Returns all generated line and column information for the original source, line, and column provided. If no column is provided, returns all mappings corresponding to a either the line we are searching for or the next closest line that has any mappings. Otherwise, returns all mappings corresponding to the given line and either the column we are searching for or the next closest column that has any offsets.

The only argument is an object with the following properties:

and an array of objects is returned, each with the following properties:

SourceMapConsumer.prototype.hasContentsOfAllSources()

Return true if we have the embedded source content for every source listed in the source map, false otherwise.

In other words, if this method returns true, then smc.sourceContentFor(s) will succeed for every source s in smc.sources.

SourceMapConsumer.prototype.sourceContentFor(source[, returnNullOnMissing])

Returns the original source content for the source provided. The only argument is the URL of the original source file.

If the source content for the given source is not found, then an error is thrown. Optionally, pass true as the second param to have null returned instead.

SourceMapConsumer.prototype.eachMapping(callback, context, order)

Iterate over each mapping between an original source/line/column and a generated line/column in this source map.

SourceMapGenerator

An instance of the SourceMapGenerator represents a source map which is being built incrementally.

new SourceMapGenerator([startOfSourceMap])

You may pass an object with the following properties:

SourceMapGenerator.fromSourceMap(sourceMapConsumer)

Creates a new SourceMapGenerator based on a SourceMapConsumer

SourceMapGenerator.prototype.addMapping(mapping)

Add a single mapping from original source line and column to the generated source's line and column for this source map being created. The mapping object should have the following properties:

SourceMapGenerator.prototype.setSourceContent(sourceFile, sourceContent)

Set the source content for an original source file.

SourceMapGenerator.prototype.applySourceMap(sourceMapConsumer[, sourceFile[, sourceMapPath]])

Applies a SourceMap for a source file to the SourceMap. Each mapping to the supplied source file is rewritten using the supplied SourceMap. Note: The resolution for the resulting mappings is the minimium of this map and the supplied map.

This parameter is needed when the two SourceMaps aren't in the same directory, and the SourceMap to be applied contains relative source paths. If so, those relative source paths need to be rewritten relative to the SourceMap.

If omitted, it is assumed that both SourceMaps are in the same directory, thus not needing any rewriting. (Supplying '.' has the same effect.)

SourceMapGenerator.prototype.toString()

Renders the source map being generated to a string.

SourceNode

SourceNodes provide a way to abstract over interpolating and/or concatenating snippets of generated JavaScript source code, while maintaining the line and column information associated between those snippets and the original source code. This is useful as the final intermediate representation a compiler might use before outputting the generated JS and source map.

new SourceNode([line, column, source[, chunk[, name]]])

SourceNode.fromStringWithSourceMap(code, sourceMapConsumer[, relativePath])

Creates a SourceNode from generated code and a SourceMapConsumer.

SourceNode.prototype.add(chunk)

Add a chunk of generated JS to this source node.

SourceNode.prototype.prepend(chunk)

Prepend a chunk of generated JS to this source node.

SourceNode.prototype.setSourceContent(sourceFile, sourceContent)

Set the source content for a source file. This will be added to the SourceMap in the sourcesContent field.

SourceNode.prototype.walk(fn)

Walk over the tree of JS snippets in this node and its children. The walking function is called once for each snippet of JS and is passed that snippet and the its original associated source's line/column location.

SourceNode.prototype.walkSourceContents(fn)

Walk over the tree of SourceNodes. The walking function is called for each source file content and is passed the filename and source content.

SourceNode.prototype.join(sep)

Like Array.prototype.join except for SourceNodes. Inserts the separator between each of this source node's children.

SourceNode.prototype.replaceRight(pattern, replacement)

Call String.prototype.replace on the very right-most source snippet. Useful for trimming whitespace from the end of a source node, etc.

SourceNode.prototype.toString()

Return the string representation of this source node. Walks over the tree and concatenates all the various snippets together to one string.

SourceNode.prototype.toStringWithSourceMap([startOfSourceMap])

Returns the string representation of this tree of source nodes, plus a SourceMapGenerator which contains all the mappings between the generated and original sources.

The arguments are the same as those to new SourceMapGenerator.

Tests

Build Status

Install NodeJS version 0.8.0 or greater, then run node test/run-tests.js.

To add new tests, create a new file named test/test-<your new test name>.js and export your test functions with names that start with "test", for example

exports["test doing the foo bar"] = function (assert, util) {
  ...
};

The new test will be located automatically when you run the suite.

The util argument is the test utility module located at test/source-map/util.

The assert argument is a cut down version of node's assert module. You have access to the following assertion functions:

(The reason for the restricted set of test functions is because we need the tests to run inside Firefox's test suite as well and so the assert module is shimmed in that environment. See build/assert-shim.js.)



thisisnic/starrating documentation built on May 18, 2019, 1:32 p.m.