Merge pull request #1777 from guybedford/self

Allow modules to import themselves

src/Bundle.js

@@ -450,19 +450,6 @@ export default class Bundle {
 							externalModule.traceExport( importDeclaration.name );
 						} );
 					} else {
-						if ( resolvedId === module.id ) {
-							// need to find the actual import declaration, so we can provide
-							// a useful error message. Bit hoop-jumpy but what can you do
-							const declaration = module.ast.body.find( node => {
-								return ( node.isImportDeclaration || node.isExportDeclaration ) && node.source.value === source;
-							} );
-							const declarationType = /Export/.test( declaration.type ) ? 'export' : 'import';
-							module.error( {
-								code: 'CANNOT_IMPORT_SELF',
-								message: `A module cannot ${declarationType} itself`
-							}, declaration.start );
-						}
-
 						module.resolvedIds[ source ] = resolvedId;
 						return this.fetchModule( resolvedId, module.id );
 					}

test/function/samples/can-import-self-treeshake/_config.js

@@ -0,0 +1,9 @@
+module.exports = {
+	description: 'direct self import',
+	warnings: [
+		{
+			code: 'EMPTY_BUNDLE',
+			message: `Generated an empty bundle`
+		}
+	]
+};

test/function/samples/can-import-self-treeshake/lib.js

@@ -0,0 +1,3 @@
+import * as lib from './lib';
+export const op = x => x * x;
+export const run = () => 4;

test/function/samples/can-import-self-treeshake/main.js

@@ -0,0 +1,2 @@
+import { run } from './lib.js';
+run();

test/function/samples/can-import-self/_config.js

@@ -0,0 +1,8 @@
+var assert = require( 'assert' );
+
+module.exports = {
+	description: 'a module importing its own bindings',
+	exports: function ( exports ) {
+		assert.equal( exports.result, 4 );
+	}
+};

test/function/samples/can-import-self/lib.js

@@ -0,0 +1,3 @@
+import * as lib from './lib';
+export const op = x => x * x;
+export const run = () => lib.op( 2 );

test/function/samples/can-import-self/main.js

@@ -0,0 +1,2 @@
+import { run } from './lib.js';
+export const result = run();