fix(compiler-cli): propagate ts.SourceFile moduleName into metadata

packages/compiler-cli/src/metadata/collector.ts

@@ -550,6 +550,7 @@ export class MetadataCollector {
         __symbolic: 'module',
         version: this.options.version || METADATA_VERSION, metadata
       };
+      if (sourceFile.moduleName) result.importAs = sourceFile.moduleName;
       if (exports) result.exports = exports;
       return result;
     }

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

@@ -112,6 +112,7 @@ function upgradeMetadataWithDtsData(
         newMetadata.metadata[prop] = dtsMetadata.metadata[prop];
       }
     }
+    if (dtsMetadata['importAs']) newMetadata['importAs'] = dtsMetadata['importAs'];
 
     // Only copy exports from exports from metadata prior to version 3.
     // Starting with version 3 the collector began collecting exports and

packages/compiler-cli/test/metadata/collector_spec.ts

@@ -45,6 +45,7 @@ describe('Collector', () => {
       're-exports.ts',
       're-exports-2.ts',
       'export-as.d.ts',
+      'named-module.d.ts',
       'static-field-reference.ts',
       'static-method.ts',
       'static-method-call.ts',
@@ -101,6 +102,12 @@ describe('Collector', () => {
     });
   });
 
+  it('should preserve module names from TypeScript sources', () => {
+    const sourceFile = program.getSourceFile('named-module.d.ts');
+    const metadata = collector.getMetadata(sourceFile);
+    expect(metadata !['importAs']).toEqual('some-named-module');
+  });
+
   it('should be able to collect a simple component\'s metadata', () => {
     const sourceFile = program.getSourceFile('app/hero-detail.component.ts');
     const metadata = collector.getMetadata(sourceFile);
@@ -1516,6 +1523,10 @@ const FILES: Directory = {
      declare function someFunction(): void;
      export { someFunction as SomeFunction };
  `,
+  'named-module.d.ts': `
+    /// <amd-module name="some-named-module" />
+    export type SomeType = 'a';
+  `,
   'local-symbol-ref.ts': `
     import {Component, Validators} from 'angular2/core';