fix(ngcc): add reexports only once (#33658)

When ngcc is configured to generate reexports for a package using the
`generateDeepReexports` configuration option, it could incorrectly
render the reexports as often as the number of compiled classes in the
declaration file. This would cause compilation errors due to duplicated
declarations.

PR Close #33658

packages/compiler-cli/ngcc/src/rendering/dts_renderer.ts

@@ -96,15 +96,15 @@ export class DtsRenderer {
         const newStatement = `    static ${declaration.name}: ${typeStr};\n`;
         outputText.appendRight(endOfClass - 1, newStatement);
       });
-
-      if (renderInfo.reexports.length > 0) {
-        for (const e of renderInfo.reexports) {
-          const newStatement = `\nexport {${e.symbolName} as ${e.asAlias}} from '${e.fromModule}';`;
-          outputText.appendRight(endOfClass, newStatement);
-        }
-      }
     });
 
+    if (renderInfo.reexports.length > 0) {
+      for (const e of renderInfo.reexports) {
+        const newStatement = `\nexport {${e.symbolName} as ${e.asAlias}} from '${e.fromModule}';`;
+        outputText.append(newStatement);
+      }
+    }
+
     this.dtsFormatter.addModuleWithProvidersParams(
         outputText, renderInfo.moduleWithProviders, importManager);
     this.dtsFormatter.addExports(

packages/compiler-cli/ngcc/test/integration/ngcc_spec.ts

@@ -918,23 +918,35 @@ runInEachFileSystem(() => {
               var __decorate = null;
               var core_1 = require("@angular/core");
               var directive_1 = require("./directive");
+              var LocalDir = /** @class */ (function () {
+                  function LocalDir() {
+                  }
+                  LocalDir = __decorate([
+                      core_1.Directive({
+                          selector: '[local]',
+                      })
+                  ], LocalDir);
+                  return LocalDir;
+              }());
               var FooModule = /** @class */ (function () {
                   function FooModule() {
                   }
                   FooModule = __decorate([
                       core_1.NgModule({
-                          declarations: [directive_1.Foo],
+                          declarations: [directive_1.Foo, LocalDir],
-                          exports: [directive_1.Foo],
+                          exports: [directive_1.Foo, LocalDir],
                       })
                   ], FooModule);
                   return FooModule;
               }());
+              exports.LocalDir = LocalDir;
               exports.FooModule = FooModule;
             `,
           },
           {
             name: _('/node_modules/test-package/module.d.ts'),
             contents: `
+              export declare class LocalDir {}
               export declare class FooModule {}
             `,
           },
@@ -1005,6 +1017,8 @@ runInEachFileSystem(() => {
         expect(jsContents).toContain('exports.ɵngExportɵFooModuleɵFoo = ɵngcc1.Foo;');
         expect(dtsContents)
             .toContain(`export {Foo as ɵngExportɵFooModuleɵFoo} from './directive';`);
+        expect(dtsContents.match(/ɵngExportɵFooModuleɵFoo/g) !.length).toBe(1);
+        expect(dtsContents).not.toContain(`ɵngExportɵFooModuleɵLocalDir`);
       });
     });