From c056b8c7f15b47c3624e309c2ab2e9b8d3ce153f Mon Sep 17 00:00:00 2001
From: Olivier Combe <olivier.combe@gmail.com>
Date: Thu, 7 Sep 2017 14:43:29 +0200
Subject: [PATCH] fix(tsc-wrapped): deduplicate metadata for re-exported
 modules

---
 packages/compiler/test/aot/compiler_spec.ts |  1 +
 packages/tsc-wrapped/src/bundler.ts         | 26 ++++++++++++++++
 packages/tsc-wrapped/test/bundler_spec.ts   | 33 +++++++++++++++++++--
 3 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/packages/compiler/test/aot/compiler_spec.ts b/packages/compiler/test/aot/compiler_spec.ts
index ef08c70c94..2fc38bb195 100644
--- a/packages/compiler/test/aot/compiler_spec.ts
+++ b/packages/compiler/test/aot/compiler_spec.ts
@@ -863,6 +863,7 @@ const LIBRARY: MockDirectory = {
     'public-api.ts': `
       export * from './src/bolder.component';
       export * from './src/bolder.module';
+      export {BolderModule as ReExportedModule} from './src/bolder.module';
     `,
     src: {
       'bolder.component.ts': `
diff --git a/packages/tsc-wrapped/src/bundler.ts b/packages/tsc-wrapped/src/bundler.ts
index 92a48744e6..fd9939e734 100644
--- a/packages/tsc-wrapped/src/bundler.ts
+++ b/packages/tsc-wrapped/src/bundler.ts
@@ -261,17 +261,43 @@ export class MetadataBundler {
 
     exportedSymbols.forEach(symbol => this.convertSymbol(symbol));
 
+    const symbolsMap = new Map<string, string[]>();
     Array.from(this.symbolMap.values()).forEach(symbol => {
       if (symbol.referenced && !symbol.reexport) {
         let name = symbol.name;
+        const declaredName = symbol.declaration !.name;
         if (symbol.isPrivate && !symbol.privateName) {
           name = newPrivateName();
           symbol.privateName = name;
         }
+        if (symbolsMap.has(declaredName)) {
+          const names = symbolsMap.get(declaredName);
+          names !.push(name);
+        } else {
+          symbolsMap.set(declaredName, [name]);
+        }
         result[name] = symbol.value !;
       }
     });
 
+    // check for duplicated entries
+    symbolsMap.forEach((names: string[], declaredName: string) => {
+      if (names.length > 1) {
+        // prefer the export that uses the declared name (if any)
+        let reference = names.indexOf(declaredName);
+        if (reference === -1) {
+          reference = 0;
+        }
+
+        // keep one entry and replace the others by references
+        names.forEach((name: string, i: number) => {
+          if (i !== reference) {
+            result[name] = {__symbolic: 'reference', name: declaredName};
+          }
+        });
+      }
+    });
+
     return result;
   }
 
diff --git a/packages/tsc-wrapped/test/bundler_spec.ts b/packages/tsc-wrapped/test/bundler_spec.ts
index 347b3c58b2..7ecbc4abea 100644
--- a/packages/tsc-wrapped/test/bundler_spec.ts
+++ b/packages/tsc-wrapped/test/bundler_spec.ts
@@ -11,7 +11,7 @@ import * as ts from 'typescript';
 
 import {MetadataBundler, MetadataBundlerHost} from '../src/bundler';
 import {MetadataCollector} from '../src/collector';
-import {ModuleMetadata} from '../src/schema';
+import {ClassMetadata, MetadataGlobalReferenceExpression, ModuleMetadata} from '../src/schema';
 
 import {Directory, open} from './typescript.mocks';
 
@@ -192,6 +192,35 @@ describe('metadata bundler', () => {
     ]);
     expect(result.metadata.origins !['E']).toBeUndefined();
   });
+
+  it('should be able to de-duplicate symbols of re-exported modules', () => {
+    const host = new MockStringBundlerHost('/', {
+      'public-api.ts': `
+        export {A as A2, A, B as B1, B as B2} from './src/core';
+      `,
+      'src': {
+        'core.ts': `
+          export class A {}
+          export class B {}
+        `,
+      }
+    });
+
+    const bundler = new MetadataBundler('/public-api', undefined, host);
+    const result = bundler.getMetadataBundle();
+    const {A, A2, B1, B2} = result.metadata.metadata as{
+      A: ClassMetadata,
+      A2: MetadataGlobalReferenceExpression,
+      B1: ClassMetadata,
+      B2: MetadataGlobalReferenceExpression
+    };
+    expect(A.__symbolic).toEqual('class');
+    expect(A2.__symbolic).toEqual('reference');
+    expect(A2.name).toEqual('A');
+    expect(B1.__symbolic).toEqual('class');
+    expect(B2.__symbolic).toEqual('reference');
+    expect(B2.name).toEqual('B');
+  });
 });
 
 export class MockStringBundlerHost implements MetadataBundlerHost {
@@ -242,4 +271,4 @@ export const SIMPLE_LIBRARY = {
       }
     }
   }
-};
\ No newline at end of file
+};