Add sourcemap support for .mjs output files

lib/SourceMapDevToolPlugin.js

@@ -84,7 +84,7 @@ class SourceMapDevToolPlugin {
 		const fallbackModuleFilenameTemplate = this.fallbackModuleFilenameTemplate;
 		const requestShortener = compiler.requestShortener;
 		const options = this.options;
-		options.test = options.test || /\.(js|css)($|\?)/i;
+		options.test = options.test || /\.(m?js|css)($|\?)/i;
 
 		const matchObject = ModuleFilenameHelpers.matchObject.bind(
 			undefined,

test/ConfigTestCases.test.js

@@ -85,12 +85,13 @@ describe("ConfigTestCases", () => {
 								});
 								let testConfig = {
 									findBundle: function(i, options) {
+										const ext = path.extname(options.output.filename);
 										if (
 											fs.existsSync(
-												path.join(options.output.path, "bundle" + i + ".js")
+												path.join(options.output.path, "bundle" + i + ext)
 											)
 										) {
-											return "./bundle" + i + ".js";
+											return "./bundle" + i + ext;
 										}
 									},
 									timeout: 30000

test/configCases/source-map/default-filename-extensions-css/index.js

@@ -0,0 +1,6 @@
+it("creates source maps for .css output files by default", function() {
+  var fs = require("fs");
+  var source = fs.readFileSync(__filename, "utf-8");
+  var match = /sourceMappingURL\s*=\s*(.*)\*\//.exec(source);
+  expect(match[1]).toBe("bundle0.css.map");
+});

test/configCases/source-map/default-filename-extensions-css/test.js

@@ -0,0 +1,3 @@
+var foo = {};
+
+module.exports = foo;

test/configCases/source-map/default-filename-extensions-css/webpack.config.js

@@ -0,0 +1,11 @@
+module.exports = {
+	mode: "development",
+	output: {
+		filename: "bundle0.css"
+	},
+	node: {
+		__dirname: false,
+		__filename: false
+	},
+	devtool: "source-map"
+};

test/configCases/source-map/default-filename-extensions-js/index.js

@@ -0,0 +1,6 @@
+it("creates source maps for .js output files by default", function() {
+  var fs = require("fs");
+  var source = fs.readFileSync(__filename, "utf-8");
+  var match = /sourceMappingURL\s*=\s*(.*)/.exec(source);
+  expect(match[1]).toBe("bundle0.js.map");
+});

test/configCases/source-map/default-filename-extensions-js/test.js

@@ -0,0 +1,3 @@
+var foo = {};
+
+module.exports = foo;

test/configCases/source-map/default-filename-extensions-js/webpack.config.js

@@ -0,0 +1,11 @@
+module.exports = {
+	mode: "development",
+	output: {
+		filename: "bundle0.js"
+	},
+	node: {
+		__dirname: false,
+		__filename: false
+	},
+	devtool: "source-map"
+};

test/configCases/source-map/default-filename-extensions-mjs/index.js

@@ -0,0 +1,6 @@
+it("creates source maps for .mjs output files by default", function() {
+	var fs = require("fs");
+	var source = fs.readFileSync(__filename, "utf-8");
+	var match = /sourceMappingURL\s*=\s*(.*)/.exec(source);
+	expect(match[1]).toBe("bundle0.mjs.map");
+});

test/configCases/source-map/default-filename-extensions-mjs/test.js

@@ -0,0 +1,3 @@
+var foo = {};
+
+module.exports = foo;

test/configCases/source-map/default-filename-extensions-mjs/webpack.config.js

@@ -0,0 +1,11 @@
+module.exports = {
+	mode: "development",
+	output: {
+		filename: "bundle0.mjs"
+	},
+	node: {
+		__dirname: false,
+		__filename: false
+	},
+	devtool: "source-map"
+};