fix(@ngtools/webpack): don't elide used imports for transformed ShorthandPropertyAssignment

NGTSC, will transform `ShorthandPropertyAssignment` to `PropertyAssignment`, with this change we handle such cases and retain the import which previously was dropped.

Closes #18149 and closes #17347

(cherry picked from commit 6ac000f)

Author: alan-agius4

packages/ngtools/webpack/src/transformers/elide_imports.ts

@@ -85,7 +85,15 @@ export function elideImports(
     } else {
       switch (node.kind) {
         case ts.SyntaxKind.Identifier:
-          symbol = typeChecker.getSymbolAtLocation(node);
+          const parent = node.parent;
+          if (parent && ts.isShorthandPropertyAssignment(parent)) {
+            const shorthandSymbol = typeChecker.getShorthandAssignmentValueSymbol(parent);
+            if (shorthandSymbol) {
+              symbol = shorthandSymbol;
+            }
+          } else {
+            symbol = typeChecker.getSymbolAtLocation(node);
+          }
           break;
         case ts.SyntaxKind.ExportSpecifier:
           symbol = typeChecker.getExportSpecifierLocalTargetSymbol(node as ts.ExportSpecifier);

packages/ngtools/webpack/src/transformers/elide_imports_spec.ts

@@ -28,6 +28,7 @@ describe('@ngtools/webpack transformers', () => {
 
     const additionalFiles: Record<string, string> = {
       'const.ts': `
+        export const animations = [];
         export const promise = () => null;
         export const take = () => null;
         export default promise;
@@ -528,6 +529,44 @@ describe('@ngtools/webpack transformers', () => {
 
         expect(tags.oneLine`${result}`).toEqual(tags.oneLine`${output}`);
       });
+
+      describe('NGTSC - ShorthandPropertyAssignment to PropertyAssignment', () => {
+        const transformShorthandPropertyAssignment = (context: ts.TransformationContext): ts.Transformer<ts.SourceFile> => {
+          const visit: ts.Visitor = node => {
+            if (ts.isShorthandPropertyAssignment(node)) {
+              return ts.createPropertyAssignment(node.name, node.name);
+            }
+
+            return ts.visitEachChild(node, child => visit(child), context);
+          };
+
+          return node => ts.visitNode(node, visit);
+        };
+
+        it('should not elide import when ShorthandPropertyAssignment is transformed to PropertyAssignment', () => {
+          const input = tags.stripIndent`
+            import { animations } from './const';
+            const used = {
+              animations
+            }
+
+            ${dummyNode}
+          `;
+
+          const output = tags.stripIndent`
+            import { animations } from './const';
+            const used = { animations: animations };
+          `;
+
+          const { program, compilerHost } = createTypescriptContext(input, additionalFiles);
+          const result = transformTypescript(undefined, [
+            transformShorthandPropertyAssignment,
+            transformer(program),
+          ], program, compilerHost);
+
+          expect(tags.oneLine`${result}`).toEqual(tags.oneLine`${output}`);
+        });
+      });
     });
   });
 });