fix(compiler): reexport less symbols in .ngfactory.ts files (#19884)

* don't reexport symbols that the user already reexported
* never reexport symbols that are part of arguments of non simple function calls

Fixes #19883

PR Close #19884

packages/compiler-cli/src/transformers/lower_expressions.ts

@@ -6,7 +6,9 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import {createLoweredSymbol, isLoweredSymbol} from '@angular/compiler';
 import * as ts from 'typescript';
+
 import {CollectorOptions, MetadataCollector, MetadataValue, ModuleMetadata, isMetadataGlobalReferenceExpression} from '../metadata/index';
 
 export interface LoweringRequest {
@@ -225,14 +227,12 @@ function shouldLower(node: ts.Node | undefined): boolean {
   return true;
 }
 
-const REWRITE_PREFIX = '\u0275';
-
 function isPrimitive(value: any): boolean {
   return Object(value) !== value;
 }
 
 function isRewritten(value: any): boolean {
-  return isMetadataGlobalReferenceExpression(value) && value.name.startsWith(REWRITE_PREFIX);
+  return isMetadataGlobalReferenceExpression(value) && isLoweredSymbol(value.name);
 }
 
 function isLiteralFieldNamed(node: ts.Node, names: Set<string>): boolean {
@@ -276,7 +276,7 @@ export class LowerMetadataCache implements RequestsMap {
 
   private getMetadataAndRequests(sourceFile: ts.SourceFile): MetadataAndLoweringRequests {
     let identNumber = 0;
-    const freshIdent = () => REWRITE_PREFIX + identNumber++;
+    const freshIdent = () => createLoweredSymbol(identNumber++);
     const requests = new Map<number, LoweringRequest>();
 
     const isExportedSymbol = (() => {

packages/compiler/src/aot/summary_resolver.ts

@@ -10,7 +10,7 @@ import {Summary, SummaryResolver} from '../summary_resolver';
 
 import {StaticSymbol, StaticSymbolCache} from './static_symbol';
 import {deserializeSummaries} from './summary_serializer';
-import {ngfactoryFilePath, stripGeneratedFileSuffix, summaryFileName} from './util';
+import {stripGeneratedFileSuffix, summaryFileName} from './util';
 
 export interface AotSummaryResolverHost {
   /**
@@ -119,11 +119,7 @@ export class AotSummaryResolver implements SummaryResolver<StaticSymbol> {
       if (moduleName) {
         this.knownFileNameToModuleNames.set(filePath, moduleName);
       }
-      importAs.forEach((importAs) => {
-        this.importAs.set(
-            importAs.symbol,
-            this.staticSymbolCache.get(ngfactoryFilePath(filePath), importAs.importAs));
-      });
+      importAs.forEach((importAs) => { this.importAs.set(importAs.symbol, importAs.importAs); });
     }
     return hasSummary;
   }

packages/compiler/src/aot/summary_serializer.ts

@@ -12,7 +12,7 @@ import {OutputContext, ValueTransformer, ValueVisitor, visitValue} from '../util
 
 import {StaticSymbol, StaticSymbolCache} from './static_symbol';
 import {ResolvedStaticSymbol, StaticSymbolResolver} from './static_symbol_resolver';
-import {summaryForJitFileName, summaryForJitName} from './util';
+import {isLoweredSymbol, ngfactoryFilePath, summaryForJitFileName, summaryForJitName} from './util';
 
 export function serializeSummaries(
     srcFileName: string, forJitCtx: OutputContext | null,
@@ -38,7 +38,7 @@ export function serializeSummaries(
   });
   const {json, exportAs} = toJsonSerializer.serialize();
   if (forJitCtx) {
-    const forJitSerializer = new ForJitSerializer(forJitCtx, symbolResolver);
+    const forJitSerializer = new ForJitSerializer(forJitCtx, symbolResolver, summaryResolver);
     types.forEach(({summary, metadata}) => { forJitSerializer.addSourceType(summary, metadata); });
     toJsonSerializer.unprocessedSymbolSummariesBySymbol.forEach((summary) => {
       if (summaryResolver.isLibraryFile(summary.symbol.filePath) && summary.type) {
@@ -55,7 +55,7 @@ export function deserializeSummaries(
     libraryFileName: string, json: string): {
   moduleName: string | null,
   summaries: Summary<StaticSymbol>[],
-  importAs: {symbol: StaticSymbol, importAs: string}[]
+  importAs: {symbol: StaticSymbol, importAs: StaticSymbol}[]
 } {
   const deserializer = new FromJsonDeserializer(symbolCache, summaryResolver);
   return deserializer.deserialize(libraryFileName, json);
@@ -83,6 +83,7 @@ class ToJsonSerializer extends ValueTransformer {
   // Note: This only contains symbols without members.
   private symbols: StaticSymbol[] = [];
   private indexBySymbol = new Map<StaticSymbol, number>();
+  private reexportedBy = new Map<StaticSymbol, StaticSymbol>();
   // This now contains a `__symbol: number` in the place of
   // StaticSymbols, but otherwise has the same shape as the original objects.
   private processedSummaryBySymbol = new Map<StaticSymbol, any>();
@@ -126,9 +127,32 @@ class ToJsonSerializer extends ValueTransformer {
           }
         });
         metadata = clone;
+      } else if (isCall(metadata)) {
+        if (!isFunctionCall(metadata) && !isMethodCallOnVariable(metadata)) {
+          // Don't store complex calls as we won't be able to simplify them anyways later on.
+          metadata = {
+            __symbolic: 'error',
+            message: 'Complex function calls are not supported.',
+          };
+        }
       }
+      // Note: We need to keep storing ctor calls for e.g.
+      // `export const x = new InjectionToken(...)`
       unprocessedSummary.metadata = metadata;
       processedSummary.metadata = this.processValue(metadata, SerializationFlags.ResolveValue);
+      if (metadata instanceof StaticSymbol &&
+          this.summaryResolver.isLibraryFile(metadata.filePath)) {
+        const declarationSymbol = this.symbols[this.indexBySymbol.get(metadata) !];
+        if (!isLoweredSymbol(declarationSymbol.name)) {
+          // Note: symbols that were introduced during codegen in the user file can have a reexport
+          // if a user used `export *`. However, we can't rely on this as tsickle will change
+          // `export *` into named exports, using only the information from the typechecker.
+          // As we introduce the new symbols after typecheck, Tsickle does not know about them,
+          // and omits them when expanding `export *`.
+          // So we have to keep reexporting these symbols manually via .ngfactory files.
+          this.reexportedBy.set(declarationSymbol, summary.symbol);
+        }
+      }
     }
     if (!unprocessedSummary.type && summary.type) {
       unprocessedSummary.type = summary.type;
@@ -161,12 +185,17 @@ class ToJsonSerializer extends ValueTransformer {
       summaries: this.processedSummaries,
       symbols: this.symbols.map((symbol, index) => {
         symbol.assertNoMembers();
-        let importAs: string = undefined !;
+        let importAs: string|number = undefined !;
         if (this.summaryResolver.isLibraryFile(symbol.filePath)) {
-          const summary = this.unprocessedSymbolSummariesBySymbol.get(symbol);
-          if (!summary || !summary.metadata || summary.metadata.__symbolic !== 'interface') {
-            importAs = `${symbol.name}_${index}`;
-            exportAs.push({symbol, exportAs: importAs});
+          const reexportSymbol = this.reexportedBy.get(symbol);
+          if (reexportSymbol) {
+            importAs = this.indexBySymbol.get(reexportSymbol) !;
+          } else {
+            const summary = this.unprocessedSymbolSummariesBySymbol.get(symbol);
+            if (!summary || !summary.metadata || summary.metadata.__symbolic !== 'interface') {
+              importAs = `${symbol.name}_${index}`;
+              exportAs.push({symbol, exportAs: importAs});
+            }
           }
         }
         return {
@@ -246,29 +275,35 @@ class ToJsonSerializer extends ValueTransformer {
 }
 
 class ForJitSerializer {
-  private data = new Map<StaticSymbol, {
+  private data: Array<{
     summary: CompileTypeSummary,
     metadata: CompileNgModuleMetadata|CompileDirectiveMetadata|CompilePipeMetadata|
     CompileTypeMetadata|null,
     isLibrary: boolean
-  }>();
+  }> = [];
 
-  constructor(private outputCtx: OutputContext, private symbolResolver: StaticSymbolResolver) {}
+  constructor(
+      private outputCtx: OutputContext, private symbolResolver: StaticSymbolResolver,
+      private summaryResolver: SummaryResolver<StaticSymbol>) {}
 
   addSourceType(
       summary: CompileTypeSummary, metadata: CompileNgModuleMetadata|CompileDirectiveMetadata|
       CompilePipeMetadata|CompileTypeMetadata) {
-    this.data.set(summary.type.reference, {summary, metadata, isLibrary: false});
+    this.data.push({summary, metadata, isLibrary: false});
   }
 
   addLibType(summary: CompileTypeSummary) {
-    this.data.set(summary.type.reference, {summary, metadata: null, isLibrary: true});
+    this.data.push({summary, metadata: null, isLibrary: true});
   }
 
-  serialize(exportAs: {symbol: StaticSymbol, exportAs: string}[]): void {
+  serialize(exportAsArr: {symbol: StaticSymbol, exportAs: string}[]): void {
+    const exportAsBySymbol = new Map<StaticSymbol, string>();
+    for (const {symbol, exportAs} of exportAsArr) {
+      exportAsBySymbol.set(symbol, exportAs);
+    }
     const ngModuleSymbols = new Set<StaticSymbol>();
 
-    Array.from(this.data.values()).forEach(({summary, metadata, isLibrary}) => {
+    for (const {summary, metadata, isLibrary} of this.data) {
       if (summary.summaryKind === CompileSummaryKind.NgModule) {
         // collect the symbols that refer to NgModule classes.
         // Note: we can't just rely on `summary.type.summaryKind` to determine this as
@@ -276,7 +311,9 @@ class ForJitSerializer {
         // See serializeSummaries for details.
         ngModuleSymbols.add(summary.type.reference);
         const modSummary = <CompileNgModuleSummary>summary;
-        modSummary.modules.forEach((mod) => { ngModuleSymbols.add(mod.reference); });
+        for (const mod of modSummary.modules) {
+          ngModuleSymbols.add(mod.reference);
+        }
       }
       if (!isLibrary) {
         const fnName = summaryForJitName(summary.type.reference.name);
@@ -284,16 +321,15 @@ class ForJitSerializer {
             this.outputCtx, summary.type.reference,
             this.serializeSummaryWithDeps(summary, metadata !));
       }
-    });
+    }
 
-    exportAs.forEach((entry) => {
-      const symbol = entry.symbol;
-      if (ngModuleSymbols.has(symbol)) {
-        const jitExportAsName = summaryForJitName(entry.exportAs);
-        this.outputCtx.statements.push(
-            o.variable(jitExportAsName).set(this.serializeSummaryRef(symbol)).toDeclStmt(null, [
-              o.StmtModifier.Exported
-            ]));
+    ngModuleSymbols.forEach((ngModuleSymbol) => {
+      if (this.summaryResolver.isLibraryFile(ngModuleSymbol.filePath)) {
+        let exportAs = exportAsBySymbol.get(ngModuleSymbol) || ngModuleSymbol.name;
+        const jitExportAsName = summaryForJitName(exportAs);
+        this.outputCtx.statements.push(o.variable(jitExportAsName)
+                                           .set(this.serializeSummaryRef(ngModuleSymbol))
+                                           .toDeclStmt(null, [o.StmtModifier.Exported]));
       }
     });
   }
@@ -378,22 +414,26 @@ class FromJsonDeserializer extends ValueTransformer {
   deserialize(libraryFileName: string, json: string): {
     moduleName: string | null,
     summaries: Summary<StaticSymbol>[],
-    importAs: {symbol: StaticSymbol, importAs: string}[]
+    importAs: {symbol: StaticSymbol, importAs: StaticSymbol}[]
   } {
     const data: {moduleName: string | null, summaries: any[], symbols: any[]} = JSON.parse(json);
-    const importAs: {symbol: StaticSymbol, importAs: string}[] = [];
-    this.symbols = [];
-    data.symbols.forEach((serializedSymbol) => {
-      const symbol = this.symbolCache.get(
-          this.summaryResolver.fromSummaryFileName(serializedSymbol.filePath, libraryFileName),
-          serializedSymbol.name);
-      this.symbols.push(symbol);
-      if (serializedSymbol.importAs) {
-        importAs.push({symbol: symbol, importAs: serializedSymbol.importAs});
+    const allImportAs: {symbol: StaticSymbol, importAs: StaticSymbol}[] = [];
+    this.symbols = data.symbols.map(
+        (serializedSymbol) => this.symbolCache.get(
+            this.summaryResolver.fromSummaryFileName(serializedSymbol.filePath, libraryFileName),
+            serializedSymbol.name));
+    data.symbols.forEach((serializedSymbol, index) => {
+      const symbol = this.symbols[index];
+      const importAs = serializedSymbol.importAs;
+      if (typeof importAs === 'number') {
+        allImportAs.push({symbol, importAs: this.symbols[importAs]});
+      } else if (typeof importAs === 'string') {
+        allImportAs.push(
+            {symbol, importAs: this.symbolCache.get(ngfactoryFilePath(libraryFileName), importAs)});
       }
     });
-    const summaries = visitValue(data.summaries, this, null);
-    return {moduleName: data.moduleName, summaries, importAs};
+    const summaries = visitValue(data.summaries, this, null) as Summary<StaticSymbol>[];
+    return {moduleName: data.moduleName, summaries, importAs: allImportAs};
   }
 
   visitStringMap(map: {[key: string]: any}, context: any): any {
@@ -407,3 +447,16 @@ class FromJsonDeserializer extends ValueTransformer {
     }
   }
 }
+
+function isCall(metadata: any): boolean {
+  return metadata && metadata.__symbolic === 'call';
+}
+
+function isFunctionCall(metadata: any): boolean {
+  return isCall(metadata) && metadata.expression instanceof StaticSymbol;
+}
+
+function isMethodCallOnVariable(metadata: any): boolean {
+  return isCall(metadata) && metadata.expression && metadata.expression.__symbolic === 'select' &&
+      metadata.expression.expression instanceof StaticSymbol;
+}

packages/compiler/src/aot/util.ts

@@ -59,3 +59,13 @@ export function summaryForJitName(symbolName: string): string {
 export function stripSummaryForJitNameSuffix(symbolName: string): string {
   return symbolName.replace(JIT_SUMMARY_NAME, '');
 }
+
+const LOWERED_SYMBOL = /\u0275\d+/;
+
+export function isLoweredSymbol(name: string) {
+  return LOWERED_SYMBOL.test(name);
+}
+
+export function createLoweredSymbol(id: number): string {
+  return `\u0275${id}`;
+}

packages/compiler/src/compiler.ts

@@ -39,6 +39,7 @@ export * from './aot/static_reflector';
 export * from './aot/static_symbol';
 export * from './aot/static_symbol_resolver';
 export * from './aot/summary_resolver';
+export {isLoweredSymbol, createLoweredSymbol} from './aot/util';
 export {LazyRoute} from './aot/lazy_routes';
 export * from './ast_path';
 export * from './summary_resolver';

packages/compiler/test/aot/compiler_spec.ts

@@ -491,10 +491,11 @@ describe('compiler (unbundled Angular)', () => {
       const libInput: MockDirectory = {
         'lib': {
           'base.ts': `
+            export class AValue {}
             export type AType = {};
 
             export class AClass {
-              constructor(a: AType) {}
+              constructor(a: AType, b: AValue) {}
             }
           `
         }
@@ -502,7 +503,7 @@ describe('compiler (unbundled Angular)', () => {
       const appInput: MockDirectory = {
         'app': {
           'main.ts': `
-            export * from '../lib/base';
+            export {AClass} from '../lib/base';
           `
         }
       };
@@ -511,7 +512,105 @@ describe('compiler (unbundled Angular)', () => {
       const {genFiles: appGenFiles} =
           compile([appInput, libOutDir, angularSummaryFiles], {useSummaries: true});
       const appNgFactory = appGenFiles.find((f) => f.genFileUrl === '/app/main.ngfactory.ts');
-      expect(toTypeScript(appNgFactory)).not.toContain('AType');
+      const appNgFactoryTs = toTypeScript(appNgFactory);
+      expect(appNgFactoryTs).not.toContain('AType');
+      expect(appNgFactoryTs).toContain('AValue');
+    });
+
+    it('should not reexport complex function calls', () => {
+      const libInput: MockDirectory = {
+        'lib': {
+          'base.ts': `
+            export class AClass {
+              constructor(arg: any) {}
+
+              static create(arg: any = null): AClass { return new AClass(arg); }
+
+              call(arg: any) {}
+            }
+
+            export function simple(arg: any) { return [arg]; }
+
+            export const ctor_arg = {};
+            export const ctor_call = new AClass(ctor_arg);
+
+            export const static_arg = {};
+            export const static_call = AClass.create(static_arg);
+
+            export const complex_arg = {};
+            export const complex_call = AClass.create().call(complex_arg);
+
+            export const simple_arg = {};
+            export const simple_call = simple(simple_arg);
+          `
+        }
+      };
+      const appInput: MockDirectory = {
+        'app': {
+          'main.ts': `
+            import {ctor_call, static_call, complex_call, simple_call} from '../lib/base';
+
+            export const calls = [ctor_call, static_call, complex_call, simple_call];
+          `,
+        }
+      };
+
+      const {outDir: libOutDir} = compile([libInput, angularSummaryFiles], {useSummaries: true});
+      const {genFiles: appGenFiles} =
+          compile([appInput, libOutDir, angularSummaryFiles], {useSummaries: true});
+      const appNgFactory = appGenFiles.find((f) => f.genFileUrl === '/app/main.ngfactory.ts');
+      const appNgFactoryTs = toTypeScript(appNgFactory);
+
+      // metadata of ctor calls is preserved, so we reexport the argument
+      expect(appNgFactoryTs).toContain('ctor_arg');
+      expect(appNgFactoryTs).toContain('ctor_call');
+
+      // metadata of static calls is preserved, so we reexport the argument
+      expect(appNgFactoryTs).toContain('static_arg');
+      expect(appNgFactoryTs).toContain('AClass');
+      expect(appNgFactoryTs).toContain('static_call');
+
+      // metadata of complex calls is elided, so we don't reexport the argument
+      expect(appNgFactoryTs).not.toContain('complex_arg');
+      expect(appNgFactoryTs).toContain('complex_call');
+
+      // metadata of simple calls is preserved, so we reexport the argument
+      expect(appNgFactoryTs).toContain('simple_arg');
+      expect(appNgFactoryTs).toContain('simple_call');
+    });
+
+    it('should not reexport already exported symbols except for lowered symbols', () => {
+      const libInput: MockDirectory = {
+        'lib': {
+          'base.ts': `
+            export const exportedVar = 1;
+
+            // A symbol introduced by lowering expressions
+            export const ɵ1 = 'lowered symbol';
+          `
+        }
+      };
+      const appInput: MockDirectory = {
+        'app': {
+          'main.ts': `export * from '../lib/base';`,
+        }
+      };
+
+      const {outDir: libOutDir} = compile([libInput, angularSummaryFiles], {useSummaries: true});
+      const {genFiles: appGenFiles} =
+          compile([appInput, libOutDir, angularSummaryFiles], {useSummaries: true});
+      const appNgFactory = appGenFiles.find((f) => f.genFileUrl === '/app/main.ngfactory.ts');
+      const appNgFactoryTs = toTypeScript(appNgFactory);
+
+      // we don't need to reexport exported symbols via the .ngfactory
+      // as we can refer to them via the reexport.
+      expect(appNgFactoryTs).not.toContain('exportedVar');
+
+      // although ɵ1 is reexported via `export *`, we still need to reexport it
+      // via the .ngfactory as tsickle expands `export *` into named exports,
+      // and doesn't know about our lowered symbols as we introduce them
+      // after the typecheck phase.
+      expect(appNgFactoryTs).toContain('ɵ1');
     });
   });
 

packages/compiler/test/aot/summary_serializer_spec.ts

@@ -317,37 +317,96 @@ export function main() {
       expect(summaries[1].metadata).toBe('someString');
     });
 
-    it('should not create "importAs" names for reexported types in libraries', () => {
+    it('should not create "importAs" names for ctor arguments which are types of reexported classes in libraries',
+       () => {
+         init();
+         const externalSerialized = serializeSummaries(
+             'someFile.ts', createMockOutputContext(), summaryResolver, symbolResolver,
+             [
+               {
+                 symbol: symbolCache.get('/tmp/external.ts', 'type'),
+                 metadata: {__symbolic: 'interface'}
+               },
+               {
+                 symbol: symbolCache.get('/tmp/external.ts', 'value'),
+                 metadata: {__symbolic: 'class'}
+               },
+               {
+                 symbol: symbolCache.get('/tmp/external.ts', 'reexportClass'),
+                 metadata: {
+                   __symbolic: 'class',
+                   'members': {
+                     '__ctor__': [{
+                       '__symbolic': 'constructor',
+                       'parameters': [
+                         symbolCache.get('/tmp/external.ts', 'type'),
+                         symbolCache.get('/tmp/external.ts', 'value'),
+                       ]
+                     }]
+                   }
+
+                 }
+               },
+             ],
+             []);
+         expect(externalSerialized.exportAs).toEqual([]);
+         init({
+           '/tmp/external.ngsummary.json': externalSerialized.json,
+         });
+         const serialized = serializeSummaries(
+             'someFile.ts', createMockOutputContext(), summaryResolver, symbolResolver, [{
+               symbol: symbolCache.get('/tmp/test.ts', 'mainClass'),
+               metadata: symbolCache.get('/tmp/external.d.ts', 'reexportClass'),
+             }],
+             []);
+         const importAs =
+             deserializeSummaries(symbolCache, summaryResolver, 'someFile.d.ts', serialized.json)
+                 .importAs;
+         expect(importAs).toEqual([
+           {
+             symbol: symbolCache.get('/tmp/external.d.ts', 'reexportClass'),
+             importAs: symbolCache.get('/tmp/test.d.ts', 'mainClass'),
+           },
+           {
+             symbol: symbolCache.get('/tmp/external.d.ts', 'value'),
+             importAs: symbolCache.get('someFile.ngfactory.d.ts', 'value_3'),
+           }
+         ]);
+       });
+
+    it('should use existing reexports for "importAs" for symbols of libraries', () => {
       init();
       const externalSerialized = serializeSummaries(
           'someFile.ts', createMockOutputContext(), summaryResolver, symbolResolver,
           [
+            {symbol: symbolCache.get('/tmp/external.ts', 'value'), metadata: 'aValue'},
             {
-              symbol: symbolCache.get('/tmp/external.ts', 'type'),
-              metadata: {__symbolic: 'interface'}
-            },
-            {
-              symbol: symbolCache.get('/tmp/external.ts', 'reexportType'),
-              metadata: symbolCache.get('/tmp/external.ts', 'type')
+              symbol: symbolCache.get('/tmp/external.ts', 'reexportValue'),
+              metadata: symbolCache.get('/tmp/external.ts', 'value')
             },
           ],
           []);
+      expect(externalSerialized.exportAs).toEqual([]);
       init({
         '/tmp/external.ngsummary.json': externalSerialized.json,
       });
       const serialized = serializeSummaries(
           'someFile.ts', createMockOutputContext(), summaryResolver, symbolResolver, [{
-            symbol: symbolCache.get('/tmp/test.ts', 'mainType'),
-            metadata: symbolCache.get('/tmp/external.d.ts', 'reexportType'),
+            symbol: symbolCache.get('/tmp/test.ts', 'mainValue'),
+            metadata: symbolCache.get('/tmp/external.d.ts', 'reexportValue'),
           }],
           []);
+      expect(serialized.exportAs).toEqual([]);
       const importAs =
           deserializeSummaries(symbolCache, summaryResolver, 'someFile.d.ts', serialized.json)
               .importAs;
-      expect(importAs).toEqual([]);
+      expect(importAs).toEqual([{
+        symbol: symbolCache.get('/tmp/external.d.ts', 'value'),
+        importAs: symbolCache.get('/tmp/test.d.ts', 'mainValue'),
+      }]);
     });
 
-    it('should create "importAs" names for non source symbols', () => {
+    it('should create reexports in the ngfactory for symbols of libraries', () => {
       init();
       const serialized = serializeSummaries(
           'someFile.ts', createMockOutputContext(), summaryResolver, symbolResolver, [{
@@ -366,9 +425,10 @@ export function main() {
       const deserialized =
           deserializeSummaries(symbolCache, summaryResolver, 'someFile.d.ts', serialized.json);
       // Note: no entry for the symbol with members!
-      expect(deserialized.importAs).toEqual([
-        {symbol: symbolCache.get('/tmp/external.d.ts', 'lib'), importAs: 'lib_1'}
-      ]);
+      expect(deserialized.importAs).toEqual([{
+        symbol: symbolCache.get('/tmp/external.d.ts', 'lib'),
+        importAs: symbolCache.get('someFile.ngfactory.d.ts', 'lib_1')
+      }]);
     });
   });
 }