fix(ngcc): handle UMD re-exports (#34254)

In TS we can re-export imports using statements of the form:

```
export * from 'some-import';
```

This is downleveled in UMD to:

```
function factory(exports, someImport) {
  function __export(m) {
    for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
  }
  __export(someImport);
}
```

This commit adds support for this.

PR Close #34254

packages/compiler-cli/ngcc/src/host/commonjs_host.ts

@@ -11,7 +11,7 @@ import {absoluteFrom} from '../../../src/ngtsc/file_system';
 import {Declaration, Import} from '../../../src/ngtsc/reflection';
 import {Logger} from '../logging/logger';
 import {BundleProgram} from '../packages/bundle_program';
-import {isDefined} from '../utils';
+import {isDefined, stripExtension} from '../utils';
 
 import {Esm5ReflectionHost} from './esm5_host';
 import {NgccClassSymbol} from './ngcc_host';
@@ -152,12 +152,12 @@ export class CommonJsReflectionHost extends Esm5ReflectionHost {
       return [];
     }
 
-    const viaModule = stripExtension(importedFile.fileName);
     const importedExports = this.getExportsOfModule(importedFile);
     if (importedExports === null) {
       return [];
     }
 
+    const viaModule = stripExtension(importedFile.fileName);
     const reexports: CommonJsExportDeclaration[] = [];
     importedExports.forEach((decl, name) => {
       if (decl.node !== null) {
@@ -259,10 +259,6 @@ function isReexportStatement(statement: ts.Statement): statement is ReexportStat
       statement.expression.arguments.length === 1;
 }
 
-function stripExtension(fileName: string): string {
-  return fileName.replace(/\..+$/, '');
-}
-
 function getOrDefault<K, V>(map: Map<K, V>, key: K, factory: (key: K) => V): V {
   if (!map.has(key)) {
     map.set(key, factory(key));

packages/compiler-cli/ngcc/src/host/umd_host.ts

@@ -12,6 +12,7 @@ import {absoluteFrom} from '../../../src/ngtsc/file_system';
 import {Declaration, Import} from '../../../src/ngtsc/reflection';
 import {Logger} from '../logging/logger';
 import {BundleProgram} from '../packages/bundle_program';
+import {stripExtension} from '../utils';
 import {Esm5ReflectionHost, stripParentheses} from './esm5_host';
 
 export class UmdReflectionHost extends Esm5ReflectionHost {
@@ -32,7 +33,10 @@ export class UmdReflectionHost extends Esm5ReflectionHost {
       return superImport;
     }
 
-    const importParameter = this.findUmdImportParameter(id);
+    // Is `id` a namespaced property access, e.g. `Directive` in `core.Directive`?
+    // If so capture the symbol of the namespace, e.g. `core`.
+    const nsIdentifier = findNamespaceOfIdentifier(id);
+    const importParameter = nsIdentifier && this.findUmdImportParameter(nsIdentifier);
     const from = importParameter && this.getUmdImportPath(importParameter);
     return from !== null ? {from, name: id.text} : null;
   }
@@ -107,14 +111,19 @@ export class UmdReflectionHost extends Esm5ReflectionHost {
 
   private computeExportsOfUmdModule(sourceFile: ts.SourceFile): Map<string, Declaration>|null {
     const moduleMap = new Map<string, Declaration>();
-    const exportStatements = this.getModuleStatements(sourceFile).filter(isUmdExportStatement);
+    for (const statement of this.getModuleStatements(sourceFile)) {
-    const exportDeclarations =
+      if (isUmdExportStatement(statement)) {
-        exportStatements.map(statement => this.extractUmdExportDeclaration(statement));
+        const declaration = this.extractUmdExportDeclaration(statement);
-    exportDeclarations.forEach(decl => {
+        if (declaration !== null) {
-      if (decl) {
+          moduleMap.set(declaration.name, declaration.declaration);
-        moduleMap.set(decl.name, decl.declaration);
+        }
+      } else if (isReexportStatement(statement)) {
+        const reexports = this.extractUmdReexports(statement, sourceFile);
+        for (const reexport of reexports) {
+          moduleMap.set(reexport.name, reexport.declaration);
+        }
+      }
     }
-    });
     return moduleMap;
   }
 
@@ -130,16 +139,43 @@ export class UmdReflectionHost extends Esm5ReflectionHost {
     return {name, declaration};
   }
 
-  private findUmdImportParameter(id: ts.Identifier): ts.ParameterDeclaration|null {
+  private extractUmdReexports(statement: ReexportStatement, containingFile: ts.SourceFile):
-    // Is `id` a namespaced property access, e.g. `Directive` in `core.Directive`?
+      UmdExportDeclaration[] {
-    // If so capture the symbol of the namespace, e.g. `core`.
+    const importParameter = this.findUmdImportParameter(statement.expression.arguments[0]);
-    const nsIdentifier = findNamespaceOfIdentifier(id);
+    const importPath = importParameter && this.getUmdImportPath(importParameter);
-    const nsSymbol = nsIdentifier && this.checker.getSymbolAtLocation(nsIdentifier) || null;
+    if (importPath === null) {
+      return [];
+    }
+    const importedFile = this.resolveModuleName(importPath, containingFile);
+    if (importedFile === undefined) {
+      return [];
+    }
 
-    // Is the namespace a parameter on a UMD factory function, e.g. `function factory(this, core)`?
+    const importedExports = this.getExportsOfModule(importedFile);
-    // If so then return its declaration.
+    if (importedExports === null) {
-    const nsDeclaration = nsSymbol && nsSymbol.valueDeclaration;
+      return [];
-    return nsDeclaration && ts.isParameter(nsDeclaration) ? nsDeclaration : null;
+    }
+
+    const viaModule = stripExtension(importedFile.fileName);
+    const reexports: UmdExportDeclaration[] = [];
+    importedExports.forEach((decl, name) => {
+      if (decl.node !== null) {
+        reexports.push({name, declaration: {node: decl.node, viaModule}});
+      } else {
+        reexports.push({name, declaration: {node: null, expression: decl.expression, viaModule}});
+      }
+    });
+    return reexports;
+  }
+
+  /**
+   * Is the identifier a parameter on a UMD factory function, e.g. `function factory(this, core)`?
+   * If so then return its declaration.
+   */
+  private findUmdImportParameter(id: ts.Identifier): ts.ParameterDeclaration|null {
+    const symbol = id && this.checker.getSymbolAtLocation(id) || null;
+    const declaration = symbol && symbol.valueDeclaration;
+    return declaration && ts.isParameter(declaration) ? declaration : null;
   }
 
   private getUmdImportedDeclaration(id: ts.Identifier): Declaration|null {
@@ -237,6 +273,15 @@ interface UmdExportDeclaration {
   declaration: Declaration;
 }
 
+type ReexportStatement = ts.ExpressionStatement & {expression: {arguments: [ts.Identifier]}};
+function isReexportStatement(statement: ts.Statement): statement is ReexportStatement {
+  return ts.isExpressionStatement(statement) && ts.isCallExpression(statement.expression) &&
+      ts.isIdentifier(statement.expression.expression) &&
+      statement.expression.expression.text === '__export' &&
+      statement.expression.arguments.length === 1 &&
+      ts.isIdentifier(statement.expression.arguments[0]);
+}
+
 function getRequiredModulePath(wrapperFn: ts.FunctionExpression, paramIndex: number): string {
   const statement = wrapperFn.body.statements[0];
   if (!ts.isExpressionStatement(statement)) {

packages/compiler-cli/ngcc/src/utils.ts

@@ -115,3 +115,7 @@ export function resolveFileWithPostfixes(
 export function stripDollarSuffix(value: string): string {
   return value.replace(/\$\d+$/, '');
 }
+
+export function stripExtension(fileName: string): string {
+  return fileName.replace(/\..+$/, '');
+}

packages/compiler-cli/ngcc/test/host/umd_host_spec.ts

@@ -546,10 +546,10 @@ runInEachFileSystem(() => {
           name: _('/index.js'),
           contents: `
           (function (global, factory) {
-            typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('./a_module'), require('./b_module')) :
+            typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('./a_module'), require('./b_module'), require('./wildcard_reexports')) :
-            typeof define === 'function' && define.amd ? define('index', ['exports', './a_module', './b_module'], factory) :
+            typeof define === 'function' && define.amd ? define('index', ['exports', './a_module', './b_module', './wildcard_reexports], factory) :
-            (factory(global.index, global.a_module, global.b_module));
+            (factory(global.index, global.a_module, global.b_module, global.wildcard_reexports));
-          }(this, (function (exports, a_module, b_module) { 'use strict';
+          }(this, (function (exports, a_module, b_module, wildcard_reexports) { 'use strict';
           })));
           `
         },
@@ -590,6 +590,35 @@ runInEachFileSystem(() => {
   exports.SomeClass = SomeClass;
 })));`,
         },
+        {
+          name: _('/xtra_module.js'),
+          contents: `
+(function (global, factory) {
+  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+  typeof define === 'function' && define.amd ? define('xtra_module', ['exports'], factory) :
+  (factory(global.xtra_module));
+}(this, (function (exports) { 'use strict';
+  var xtra1 = 'xtra1';
+  var xtra2 = 'xtra2';
+  exports.xtra1 = xtra1;
+  exports.xtra2 = xtra2;
+})));`,
+        },
+        {
+          name: _('/wildcard_reexports.js'),
+          contents: `
+(function (global, factory) {
+  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('./b_module'), require('./xtra_module')) :
+  typeof define === 'function' && define.amd ? define('wildcard_reexports', ['exports', './b_module', './xtra_module'], factory) :
+  (factory(global.wildcard_reexports, b_module, xtra_module));
+}(this, (function (exports, b_module, xtra_module) { 'use strict';
+  function __export(m) {
+    for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
+  }
+__export(b_module);
+__export(xtra_module);
+})));`,
+        }
       ];
 
       FUNCTION_BODY_FILE = {
@@ -1862,6 +1891,34 @@ runInEachFileSystem(() => {
         expect(classSymbol !.implementation.valueDeclaration).toBe(node);
       });
 
+      it('should handle wildcard re-exports of other modules', () => {
+        loadFakeCore(getFileSystem());
+        loadTestFiles(EXPORTS_FILES);
+        const bundle = makeTestBundleProgram(_('/index.js'));
+        const host = new UmdReflectionHost(new MockLogger(), false, bundle);
+        const file = getSourceFileOrError(bundle.program, _('/wildcard_reexports.js'));
+        const exportDeclarations = host.getExportsOfModule(file);
+        expect(exportDeclarations).not.toBe(null);
+        expect(Array.from(exportDeclarations !.entries())
+                   .map(entry => [entry[0], entry[1].node !.getText(), entry[1].viaModule]))
+            .toEqual([
+              ['Directive', `Directive: FnWithArg<(clazz: any) => any>`, _('/b_module')],
+              ['a', `a = 'a'`, _('/b_module')],
+              ['b', `b = a_module.a`, _('/b_module')],
+              ['c', `a = 'a'`, _('/b_module')],
+              ['d', `b = a_module.a`, _('/b_module')],
+              ['e', `e = 'e'`, _('/b_module')],
+              ['DirectiveX', `Directive: FnWithArg<(clazz: any) => any>`, _('/b_module')],
+              [
+                'SomeClass',
+                `SomeClass = (function() {\n    function SomeClass() {}\n    return SomeClass;\n  }())`,
+                _('/b_module')
+              ],
+              ['xtra1', `xtra1 = 'xtra1'`, _('/xtra_module')],
+              ['xtra2', `xtra2 = 'xtra2'`, _('/xtra_module')],
+            ]);
+      });
+
       it('should return the class symbol for an ES5 class (outer variable declaration)', () => {
         loadTestFiles([SIMPLE_CLASS_FILE]);
         const bundle = makeTestBundleProgram(SIMPLE_CLASS_FILE.name);