ng annotate webpack loader with source map support

ng-annotate-loader.js

var ngAnnotate = require('ng-annotate');
var utils = require('loader-utils');
var SourceMapConsumer = require('source-map').SourceMapConsumer;
var SourceMapGenerator = require('source-map').SourceMapGenerator;

module.exports = function(content, sm) {
    var filename = utils.getCurrentRequest(this);

    var res = ngAnnotate(content, {
            add : true,
            sourcemap : {inline: false, inFile : filename, sourceRoot:filename}
        }
    );

    var mergeMap = null;
    if(sm) {
        var generator = SourceMapGenerator.fromSourceMap(new SourceMapConsumer(sm));
        generator.applySourceMap(new SourceMapConsumer(res.map), filename);
        mergeMap = generator.toString();
    }

    this.callback(null, res.src, mergeMap);
};

Found that this could be improved by checking if there's a res.map and not merging if there's not:

var ngAnnotate = require('ng-annotate');
var utils = require('loader-utils');
var SourceMapConsumer = require('source-map').SourceMapConsumer;
var SourceMapGenerator = require('source-map').SourceMapGenerator;

module.exports = function(source, sm) {
  var filename = utils.getCurrentRequest(this);

  var res = ngAnnotate(source, {
      add: true,
      sourcemap: {inline: false, inFile: filename, sourceRoot: filename}
    }
  );

  var mergeMap;
  if (sm) {
    var generator = SourceMapGenerator.fromSourceMap(new SourceMapConsumer(sm));
    if (res.map) {
      generator.applySourceMap(new SourceMapConsumer(res.map), filename);
      mergeMap = generator.toString();
    } else {
      mergeMap = sm;
    }
  }

  this.callback(null, res.src || source, mergeMap);
};

But of course you don't get an email, so you may never know about this... Unless... @sloosch?

Oh, and don't forget to cache!

var ngAnnotate = require('ng-annotate');
var utils = require('loader-utils');
var SourceMapConsumer = require('source-map').SourceMapConsumer;
var SourceMapGenerator = require('source-map').SourceMapGenerator;

module.exports = function(source, sm) {
  this.cacheable && this.cacheable();
  var filename = utils.getCurrentRequest(this);

  var res = ngAnnotate(source, {
      add: true,
      sourcemap: {inline: false, inFile: filename, sourceRoot: filename}
    }
  );

  var mergeMap;
  if (sm) {
    var generator = SourceMapGenerator.fromSourceMap(new SourceMapConsumer(sm));
    if (res.map) {
      generator.applySourceMap(new SourceMapConsumer(res.map), filename);
      mergeMap = generator.toString();
    } else {
      mergeMap = sm;
    }
  }

  this.callback(null, res.src || source, mergeMap);
};

P.S. Made a PR to the repo that owns the ng-annotate-loader name on npm: andrey-skl/ng-annotate-loader#2