preserve debugger statements. closes #664

src/utils/run.js

@@ -75,6 +75,10 @@ export default function run ( node, scope, statement, strongDependencies, force
 				}
 			}
 
+			else if ( node.type === 'DebuggerStatement' ) {
+				hasSideEffect = true;
+			}
+
 			else if ( node.type === 'ThrowStatement' ) {
 				// we only care about errors thrown at the top level, otherwise
 				// any function with error checking gets included if called

test/form/preserve-debugger/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'debugger statements are preserved (#664)'
+};

test/form/preserve-debugger/_expected/amd.js

@@ -0,0 +1,7 @@
+define(function () { 'use strict';
+
+	before();
+	debugger;
+	after();
+
+});

test/form/preserve-debugger/_expected/cjs.js

@@ -0,0 +1,5 @@
+'use strict';
+
+before();
+debugger;
+after();

test/form/preserve-debugger/_expected/es6.js

@@ -0,0 +1,3 @@
+before();
+debugger;
+after();

test/form/preserve-debugger/_expected/iife.js

@@ -0,0 +1,8 @@
+(function () {
+	'use strict';
+
+	before();
+	debugger;
+	after();
+
+}());

test/form/preserve-debugger/_expected/umd.js

@@ -0,0 +1,11 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	(factory());
+}(this, function () { 'use strict';
+
+	before();
+	debugger;
+	after();
+
+}));

test/form/preserve-debugger/main.js

@@ -0,0 +1,3 @@
+before();
+debugger;
+after();