webpack/lib/optimize/UglifyJsPlugin.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var SourceMapConsumer = require("source-map").SourceMapConsumer;
var SourceMapSource = require("webpack-sources").SourceMapSource;
var RawSource = require("webpack-sources").RawSource;
var RequestShortener = require("../RequestShortener");
var ModuleFilenameHelpers = require("../ModuleFilenameHelpers");
var uglify = require("uglify-js");

function UglifyJsPlugin(options) {
	if(typeof options !== "object") options = {};
	if(typeof options.compressor !== "undefined") {
		options.compress = options.compressor;
	}
	this.options = options;
}
module.exports = UglifyJsPlugin;

UglifyJsPlugin.prototype.apply = function(compiler) {
	var options = this.options;
	options.test = options.test || /\.js($|\?)/i;

	var requestShortener = new RequestShortener(compiler.context);
	compiler.plugin("compilation", function(compilation) {
		if(options.sourceMap) {
			compilation.plugin("build-module", function(module) {
				// to get detailed location info about errors
				module.useSourceMap = true;
			});
		}
		compilation.plugin("optimize-chunk-assets", function(chunks, callback) {
			var files = [];
			chunks.forEach(function(chunk) {
				chunk.files.forEach(function(file) {
					files.push(file);
				});
			});
			compilation.additionalChunkAssets.forEach(function(file) {
				files.push(file);
			});
			files = files.filter(ModuleFilenameHelpers.matchObject.bind(undefined, options));
			files.forEach(function(file) {
				var oldWarnFunction = uglify.AST_Node.warn_function;
				var warnings = [];
				try {
					var asset = compilation.assets[file];
					if(asset.__UglifyJsPlugin) {
						compilation.assets[file] = asset.__UglifyJsPlugin;
						return;
					}
					var input;
					if(options.sourceMap) {
						var inputSourceMap;
						if(asset.sourceAndMap) {
							var sourceAndMap = asset.sourceAndMap();
							inputSourceMap = sourceAndMap.map;
							input = sourceAndMap.source;
						} else {
							inputSourceMap = asset.map();
							input = asset.source();
						}
						var sourceMap = new SourceMapConsumer(inputSourceMap);
						uglify.AST_Node.warn_function = function(warning) { // eslint-disable-line camelcase
							var match = /\[.+:([0-9]+),([0-9]+)\]/.exec(warning);
							var line = +match[1];
							var column = +match[2];
							var original = sourceMap.originalPositionFor({
								line: line,
								column: column
							});
							if(!original || !original.source || original.source === file) return;
							warnings.push(warning.replace(/\[.+:([0-9]+),([0-9]+)\]/, "") +
								"[" + requestShortener.shorten(original.source) + ":" + original.line + "," + original.column + "]");
						};
					} else {
						input = asset.source();
						uglify.AST_Node.warn_function = function(warning) { // eslint-disable-line camelcase
							warnings.push(warning);
						};
					}
					uglify.base54.reset();
					var ast = uglify.parse(input, {
						filename: file
					});
					if(options.compress !== false) {
						ast.figure_out_scope();
						var compress = uglify.Compressor(options.compress || {
							warnings: false
						}); // eslint-disable-line new-cap
						ast = ast.transform(compress);
					}
					if(options.mangle !== false) {
						ast.figure_out_scope();
						ast.compute_char_frequency(options.mangle || {});
						ast.mangle_names(options.mangle || {});
						if(options.mangle && options.mangle.props) {
							uglify.mangle_properties(ast, options.mangle.props);
						}
					}
					var output = {};
					output.comments = Object.prototype.hasOwnProperty.call(options, "comments") ? options.comments : /^\**!|@preserve|@license/;
					output.beautify = options.beautify;
					for(var k in options.output) {
						output[k] = options.output[k];
					}
					if(options.sourceMap) {
						var map = uglify.SourceMap({ // eslint-disable-line new-cap
							file: file,
							root: ""
						});
						output.source_map = map; // eslint-disable-line camelcase
					}
					var stream = uglify.OutputStream(output); // eslint-disable-line new-cap
					ast.print(stream);
					if(map) map = map + "";
					stream = stream + "";
					asset.__UglifyJsPlugin = compilation.assets[file] = (map ?
						new SourceMapSource(stream, file, JSON.parse(map), input, inputSourceMap) :
						new RawSource(stream));
					if(warnings.length > 0) {
						compilation.warnings.push(new Error(file + " from UglifyJs\n" + warnings.join("\n")));
					}
				} catch(err) {
					if(err.line) {
						var original = sourceMap && sourceMap.originalPositionFor({
							line: err.line,
							column: err.col
						});
						if(original && original.source) {
							compilation.errors.push(new Error(file + " from UglifyJs\n" + err.message + " [" + requestShortener.shorten(original.source) + ":" + original.line + "," + original.column + "][" + file + ":" + err.line + "," + err.col + "]"));
						} else {
							compilation.errors.push(new Error(file + " from UglifyJs\n" + err.message + " [" + file + ":" + err.line + "," + err.col + "]"));
						}
					} else if(err.msg) {
						compilation.errors.push(new Error(file + " from UglifyJs\n" + err.msg));
					} else
						compilation.errors.push(new Error(file + " from UglifyJs\n" + err.stack));
				} finally {
					uglify.AST_Node.warn_function = oldWarnFunction; // eslint-disable-line camelcase
				}
			});
			callback();
		});
	});
};