feat(cli-internal): use cdk assets for vtl resolver overrides

Author: dgandhi62

packages/amplify-cli/src/__tests__/commands/gen2-migration/generate/amplify/data/data.generator.test.ts

@@ -414,6 +414,7 @@ describe('DataGenerator', () => {
         mockReaddirSync.mockReturnValue(['Query.listProducts.res.vtl']);
 
         const addImportSpy = jest.spyOn(backendGenerator, 'addImport');
+        const addNamespaceImportSpy = jest.spyOn(backendGenerator, 'addNamespaceImport');
         const addStatementSpy = jest.spyOn(backendGenerator, 'addStatement');
 
         const generator = new DataGenerator(gen1App, backendGenerator, outputDir, {
@@ -425,10 +426,11 @@ describe('DataGenerator', () => {
         const ops = await generator.plan();
         await ops[0].execute();
 
-        // Resolver imports: fs, path, url
-        expect(addImportSpy).toHaveBeenCalledWith('fs', ['readFileSync', 'readdirSync']);
+        // Resolver imports: fs (readdirSync only), path, url
+        expect(addImportSpy).toHaveBeenCalledWith('fs', ['readdirSync']);
         expect(addImportSpy).toHaveBeenCalledWith('path', ['join', 'dirname']);
         expect(addImportSpy).toHaveBeenCalledWith('url', ['fileURLToPath']);
+        expect(addNamespaceImportSpy).toHaveBeenCalledWith('aws-cdk-lib/aws-s3-assets', 'assets');
 
         // 4 statements: __dirname, resolversDir, resolverFiles, for-of loop
         expect(addStatementSpy).toHaveBeenCalledTimes(4);

packages/amplify-cli/src/commands/gen2-migration/generate/amplify/backend.generator.ts

@@ -18,6 +18,7 @@ const factory = ts.factory;
  */
 export class BackendGenerator implements Planner {
   private readonly imports: Array<{ readonly source: string; readonly identifiers: string[] }> = [];
+  private readonly namespaceImports: Array<{ readonly source: string; readonly alias: string }> = [];
   private readonly defineBackendProperties: ts.ObjectLiteralElementLike[] = [];
   private readonly postDefineStatements: ts.Statement[] = [];
   private readonly earlyStatements: ts.Statement[] = [];
@@ -46,6 +47,15 @@ export class BackendGenerator implements Planner {
     }
   }
 
+  /**
+   * Adds a namespace import (`import * as alias from 'source'`) to backend.ts.
+   */
+  public addNamespaceImport(source: string, alias: string): void {
+    if (!this.namespaceImports.some((i) => i.source === source)) {
+      this.namespaceImports.push({ source, alias });
+    }
+  }
+
   /**
    * Adds a property to the `defineBackend({ ... })` call.
    */
@@ -122,6 +132,12 @@ export class BackendGenerator implements Planner {
             nodes.push(createImportDeclaration(imp.source, imp.identifiers));
           }
 
+          // Namespace imports (import * as X from 'source'), sorted by importOrder
+          const sortedNamespaceImports = [...this.namespaceImports].sort((a, b) => importOrder(a.source) - importOrder(b.source));
+          for (const ns of sortedNamespaceImports) {
+            nodes.push(createNamespaceImportDeclaration(ns.source, ns.alias));
+          }
+
           // Sort defineBackend properties: auth first, then data, storage, then functions
           const sortedProperties = [...this.defineBackendProperties].sort((a, b) => {
             const getName = (prop: ts.ObjectLiteralElementLike): string => {
@@ -186,6 +202,14 @@ function createImportDeclaration(source: string, identifiers: string[]): ts.Impo
   );
 }
 
+function createNamespaceImportDeclaration(source: string, alias: string): ts.ImportDeclaration {
+  return factory.createImportDeclaration(
+    undefined,
+    factory.createImportClause(false, undefined, factory.createNamespaceImport(factory.createIdentifier(alias))),
+    factory.createStringLiteral(source),
+  );
+}
+
 /**
  * Returns a numeric sort key for import source paths.
  *

packages/amplify-cli/src/commands/gen2-migration/generate/amplify/data/data.generator.ts

@@ -311,15 +311,16 @@ export class DataGenerator implements Planner {
   /**
    * Contributes resolver override statements to backend.ts.
    *
-   * Generates code that reads VTL files from `data/resolvers/` at runtime
-   * and overrides the pipeline function response mapping templates, replacing
-   * the S3-based templates with inline content.
+   * Generates code that reads VTL files from `data/resolvers/` at deploy
+   * time, uploads them as CDK Assets to S3, and overrides the pipeline
+   * function mapping template S3 locations.
    */
   private contributeResolverOverrides(): void {
     // Imports for the generated backend.ts file
-    this.backendGenerator.addImport('fs', ['readFileSync', 'readdirSync']);
+    this.backendGenerator.addImport('fs', ['readdirSync']);
     this.backendGenerator.addImport('path', ['join', 'dirname']);
     this.backendGenerator.addImport('url', ['fileURLToPath']);
+    this.backendGenerator.addNamespaceImport('aws-cdk-lib/aws-s3-assets', 'assets');
 
     // const __dirname = dirname(fileURLToPath(import.meta.url));
     this.backendGenerator.addStatement(
@@ -399,13 +400,12 @@ export class DataGenerator implements Planner {
    *   const functionId = `${typeName}${fieldName.charAt(0).toUpperCase() + fieldName.slice(1)}DataResolverFn`;
    *   const pipelineFunction = backend.data.resources.cfnResources.cfnFunctionConfigurations[functionId];
    *   if (pipelineFunction) {
-   *     const template = readFileSync(join(resolversDir, file), "utf8");
+   *     const templatePath = join(resolversDir, file);
+   *     const vtlTemplate = new assets.Asset(backend.data, `VTLTemplate-${file}`, { path: templatePath });
    *     if (isRequest) {
-   *       pipelineFunction.requestMappingTemplateS3Location = undefined;
-   *       pipelineFunction.requestMappingTemplate = template;
+   *       pipelineFunction.requestMappingTemplateS3Location = vtlTemplate.s3ObjectUrl;
    *     } else {
-   *       pipelineFunction.responseMappingTemplateS3Location = undefined;
-   *       pipelineFunction.responseMappingTemplate = template;
+   *       pipelineFunction.responseMappingTemplateS3Location = vtlTemplate.s3ObjectUrl;
    *     }
    *   }
    * }
@@ -530,17 +530,32 @@ export class DataGenerator implements Planner {
       factory.createIdentifier('pipelineFunction'),
       factory.createBlock(
         [
-          // const template = readFileSync(join(resolversDir, file), "utf8");
+          // const templatePath = join(resolversDir, file);
           TS.constDecl(
-            'template',
-            factory.createCallExpression(factory.createIdentifier('readFileSync'), undefined, [
-              factory.createCallExpression(factory.createIdentifier('join'), undefined, [
-                factory.createIdentifier('resolversDir'),
-                factory.createIdentifier('file'),
-              ]),
-              factory.createStringLiteral('utf8'),
+            'templatePath',
+            factory.createCallExpression(factory.createIdentifier('join'), undefined, [
+              factory.createIdentifier('resolversDir'),
+              factory.createIdentifier('file'),
             ]),
           ),
+          // const vtlTemplate = new assets.Asset(backend.data, `VTLTemplate-${file}`, { path: templatePath });
+          TS.constDecl(
+            'vtlTemplate',
+            factory.createNewExpression(
+              factory.createPropertyAccessExpression(factory.createIdentifier('assets'), factory.createIdentifier('Asset')),
+              undefined,
+              [
+                TS.propAccess('backend', 'data') as ts.Expression,
+                factory.createTemplateExpression(factory.createTemplateHead('VTLTemplate-'), [
+                  factory.createTemplateSpan(factory.createIdentifier('file'), factory.createTemplateTail('')),
+                ]),
+                factory.createObjectLiteralExpression(
+                  [factory.createPropertyAssignment('path', factory.createIdentifier('templatePath'))],
+                  false,
+                ),
+              ],
+            ),
+          ),
           // if (isRequest) { ... } else { ... }
           factory.createIfStatement(
             factory.createIdentifier('isRequest'),
@@ -552,16 +567,10 @@ export class DataGenerator implements Planner {
                       factory.createIdentifier('pipelineFunction'),
                       factory.createIdentifier('requestMappingTemplateS3Location'),
                     ),
-                    factory.createIdentifier('undefined'),
-                  ),
-                ),
-                factory.createExpressionStatement(
-                  factory.createAssignment(
                     factory.createPropertyAccessExpression(
-                      factory.createIdentifier('pipelineFunction'),
-                      factory.createIdentifier('requestMappingTemplate'),
+                      factory.createIdentifier('vtlTemplate'),
+                      factory.createIdentifier('s3ObjectUrl'),
                     ),
-                    factory.createIdentifier('template'),
                   ),
                 ),
               ],
@@ -575,16 +584,10 @@ export class DataGenerator implements Planner {
                       factory.createIdentifier('pipelineFunction'),
                       factory.createIdentifier('responseMappingTemplateS3Location'),
                     ),
-                    factory.createIdentifier('undefined'),
-                  ),
-                ),
-                factory.createExpressionStatement(
-                  factory.createAssignment(
                     factory.createPropertyAccessExpression(
-                      factory.createIdentifier('pipelineFunction'),
-                      factory.createIdentifier('responseMappingTemplate'),
+                      factory.createIdentifier('vtlTemplate'),
+                      factory.createIdentifier('s3ObjectUrl'),
                     ),
-                    factory.createIdentifier('template'),
                   ),
                 ),
               ],