fix(ivy): process separate declarations and exports for summaries (#29193)

ngsummary files were generated with an export for each class declaration.
However, some Angular code declares classes (class Foo) and exports them
(export {Foo}) separately, which was causing incomplete summary files.

This commit expands the set of symbol names for which summary exports will
be generated, fixing this issue.

PR Close #29193

packages/compiler-cli/src/ngtsc/shims/src/summary_generator.ts

@@ -34,16 +34,31 @@ export class SummaryGenerator implements ShimGenerator {
     // to semantically understand which decorators are Angular decorators. It's okay to output an
     // overly broad set of summary exports as the exports are no-ops anyway, and summaries are a
     // compatibility layer which will be removed after Ivy is enabled.
-    const symbolNames = original
-                            .statements
-                            // Pick out top level class declarations...
-                            .filter(ts.isClassDeclaration)
-                            // which are named, exported, and have decorators.
-                            .filter(
-                                decl => isExported(decl) && decl.decorators !== undefined &&
-                                    decl.name !== undefined)
-                            // Grab the symbol name.
-                            .map(decl => decl.name !.text);
+    const symbolNames: string[] = [];
+    for (const stmt of original.statements) {
+      if (ts.isClassDeclaration(stmt)) {
+        // If the class isn't exported, or if it's not decorated, then skip it.
+        if (!isExported(stmt) || stmt.decorators === undefined || stmt.name === undefined) {
+          continue;
+        }
+        symbolNames.push(stmt.name.text);
+      } else if (ts.isExportDeclaration(stmt)) {
+        // Look for an export statement of the form "export {...};". If it doesn't match that, then
+        // skip it.
+        if (stmt.exportClause === undefined || stmt.moduleSpecifier !== undefined) {
+          continue;
+        }
+
+        for (const specifier of stmt.exportClause.elements) {
+          // At this point, there is no guarantee that specifier here refers to a class declaration,
+          // but that's okay.
+
+          // Use specifier.name as that's guaranteed to be the exported name, regardless of whether
+          // specifier.propertyName is set.
+          symbolNames.push(specifier.name.text);
+        }
+      }
+    }
 
     const varLines = symbolNames.map(name => `export const ${name}NgSummary: any = null;`);
 

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -1768,6 +1768,24 @@ describe('ngtsc behavioral tests', () => {
     expect(summaryContents).toEqual(`export var TestModuleNgSummary = null;\n`);
   });
 
+  it('should generate a summary stub for classes exported via exports', () => {
+    env.tsconfig({'allowEmptyCodegenFiles': true});
+
+    env.write('test.ts', `
+        import {Injectable, NgModule} from '@angular/core';
+
+        @NgModule({})
+        class NotDirectlyExported {}
+
+        export {NotDirectlyExported};
+    `);
+
+    env.driveMain();
+
+    const summaryContents = env.getContents('test.ngsummary.js');
+    expect(summaryContents).toEqual(`export var NotDirectlyExportedNgSummary = null;\n`);
+  });
+
   it('it should generate empty export when there are no other summary symbols, to ensure the output is a valid ES module',
      () => {
        env.tsconfig({'allowEmptyCodegenFiles': true});