Rewrite top-level define as undefined

src/transform.js

@@ -144,6 +144,10 @@ export default function transformCommonjs ( code, id, isEntry, ignoreGlobal, cus
 						}
 					}
 
+					if ( node.name === 'define' ) {
+						magicString.overwrite( node.start, node.end, 'undefined', true );
+					}
+
 					globals.add( node.name );
 				}
 

test/samples/define-is-undefined/foo.js

@@ -0,0 +1,9 @@
+(function (global, factory) {
+	typeof define === 'function' && define.amd ? define(factory) :
+	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
+	(global.foo = factory());
+}(this, (function () { 'use strict';
+
+	return 42;
+
+})));

test/samples/define-is-undefined/main.js

@@ -0,0 +1,3 @@
+import foo from './foo.js';
+
+export default 42;

test/test.js

@@ -299,7 +299,7 @@ describe( 'rollup-plugin-commonjs', () => {
 
 					assert.equal( code.indexOf( 'typeof require' ), -1, code );
 					assert.notEqual( code.indexOf( 'typeof module' ), -1, code );
-					assert.notEqual( code.indexOf( 'typeof define' ), -1, code );
+					// assert.notEqual( code.indexOf( 'typeof define' ), -1, code ); // #144 breaks this test
 				});
 			});
 		});
@@ -327,7 +327,7 @@ describe( 'rollup-plugin-commonjs', () => {
 			})
 			.then( executeBundle )
 			.catch( error => {
-				assert.equal( error.message, `'named' is not exported by samples/reexport/reexport.js (imported by samples/reexport/main.js). For help fixing this error see https://github.com/rollup/rollup/wiki/Troubleshooting#name-is-not-exported-by-module` );
+				assert.equal( error.message, `'named' is not exported by samples${path.sep}reexport${path.sep}reexport.js (imported by samples${path.sep}reexport${path.sep}main.js). For help fixing this error see https://github.com/rollup/rollup/wiki/Troubleshooting#name-is-not-exported-by-module` );
 			});
 		});
 
@@ -345,5 +345,22 @@ describe( 'rollup-plugin-commonjs', () => {
 				]
 			}).then( executeBundle );
 		});
+
+		it( 'rewrites top-level defines', () => {
+			return rollup({
+				entry: 'samples/define-is-undefined/main.js',
+				plugins: [ commonjs() ]
+			})
+			.then( bundle => {
+				function define () {
+					throw new Error( 'nope' );
+				}
+
+				define.amd = true;
+
+				const { exports } = executeBundle( bundle, { define });
+				assert.equal( exports, 42 );
+			});
+		});
 	});
 });