fix(migrate-template-gen): resolve all outputs

packages/amplify-migration-template-gen/src/category-template-generator.test.ts

@@ -1,6 +1,13 @@
 import CategoryTemplateGenerator from './category-template-generator';
 import { CFN_S3_TYPE, CFNTemplate } from './types';
-import { CloudFormationClient, DescribeStacksCommand, GetTemplateCommand, Parameter } from '@aws-sdk/client-cloudformation';
+import {
+  CloudFormationClient,
+  DescribeStacksCommand,
+  DescribeStacksOutput,
+  GetTemplateCommand,
+  GetTemplateOutput,
+  Parameter,
+} from '@aws-sdk/client-cloudformation';
 
 const mockCfnClientSendMock = jest.fn();
 
@@ -230,6 +237,7 @@ const gen1Params: Parameter[] = [
     ParameterValue: 'dev',
   },
 ];
+
 const refactoredGen1Template: CFNTemplate = {
   ...newGen1Template,
   Resources: {
@@ -285,44 +293,47 @@ const refactoredGen2Template: CFNTemplate = {
   },
 };
 
+const generateDescribeStacksResponse = (command: DescribeStacksCommand): DescribeStacksOutput => ({
+  Stacks: [
+    {
+      StackId: command.input.StackName,
+      StackName: command.input.StackName,
+      Capabilities: ['CAPABILITY_NAMED_IAM'],
+      Tags: [
+        {
+          Key: 'amplify:category-stack',
+          Value: 'amplify-testauth-dev-12345-auth-ABCDE',
+        },
+      ],
+      CreationTime: new Date(),
+      LastUpdatedTime: new Date(),
+      StackStatus: 'CREATE_COMPLETE',
+      Parameters: gen1Params,
+      Outputs: [
+        {
+          OutputKey: 'BucketNameOutputRef',
+          OutputValue: 'my-test-bucket-dev',
+          Description: 'My bucket',
+        },
+      ],
+    },
+  ],
+});
+
+const generateGetTemplateResponse = (command: GetTemplateCommand): GetTemplateOutput => ({
+  TemplateBody: command.input.StackName === GEN1_CATEGORY_STACK_ID ? JSON.stringify(oldGen1Template) : JSON.stringify(oldGen2Template),
+});
+
 jest.mock('@aws-sdk/client-cloudformation', () => {
   return {
     ...jest.requireActual('@aws-sdk/client-cloudformation'),
     CloudFormationClient: function () {
       return {
         send: mockCfnClientSendMock.mockImplementation((command) => {
           if (command instanceof DescribeStacksCommand) {
-            return Promise.resolve({
-              Stacks: [
-                {
-                  StackId: command.input.StackName,
-                  Capabilities: ['CAPABILITY_NAMED_IAM'],
-                  Tags: [
-                    {
-                      Key: 'amplify:category-stack',
-                      Value: 'amplify-testauth-dev-12345-auth-ABCDE',
-                    },
-                  ],
-                  CreationTime: new Date(),
-                  LastUpdatedTime: new Date(),
-                  DeletionTime: null,
-                  StackStatus: 'CREATE_COMPLETE',
-                  Parameters: gen1Params,
-                  Outputs: [
-                    {
-                      OutputKey: 'BucketNameOutputRef',
-                      OutputValue: 'my-test-bucket-dev',
-                      Description: 'My bucket',
-                    },
-                  ],
-                },
-              ],
-            });
+            return Promise.resolve(generateDescribeStacksResponse(command));
           } else if (command instanceof GetTemplateCommand) {
-            return Promise.resolve({
-              TemplateBody:
-                command.input.StackName === GEN1_CATEGORY_STACK_ID ? JSON.stringify(oldGen1Template) : JSON.stringify(oldGen2Template),
-            });
+            return Promise.resolve(generateGetTemplateResponse(command));
           }
           return Promise.resolve({});
         }),
@@ -331,6 +342,9 @@ jest.mock('@aws-sdk/client-cloudformation', () => {
   };
 });
 
+const oldGen1TemplateWithoutS3Bucket = JSON.parse(JSON.stringify(oldGen1Template)) as CFNTemplate;
+delete oldGen1TemplateWithoutS3Bucket.Resources[GEN1_S3_BUCKET_LOGICAL_ID];
+
 describe('CategoryTemplateGenerator', () => {
   const s3TemplateGenerator = new CategoryTemplateGenerator(
     GEN1_CATEGORY_STACK_ID,
@@ -352,6 +366,15 @@ describe('CategoryTemplateGenerator', () => {
     (resourcesToMove, resourceEntry) => resourcesToMove.includes(CFN_S3_TYPE.Bucket) && resourceEntry[0] === GEN1_S3_BUCKET_LOGICAL_ID,
   );
 
+  const noGen1ResourcesToMoveS3TemplateGenerator = new CategoryTemplateGenerator(
+    GEN1_CATEGORY_STACK_ID,
+    GEN2_CATEGORY_STACK_ID,
+    'us-east-1',
+    '12345',
+    new CloudFormationClient(),
+    [CFN_S3_TYPE.Bucket],
+  );
+
   it('should preprocess gen1 template prior to refactor', async () => {
     await expect(s3TemplateGenerator.generateGen1PreProcessTemplate()).resolves.toEqual({
       oldTemplate: oldGen1Template,
@@ -392,4 +415,22 @@ describe('CategoryTemplateGenerator', () => {
       ]),
     );
   });
+
+  it('should throw error when there are no resources to move', async () => {
+    const sendFailureMock = (command: any) => {
+      if (command instanceof DescribeStacksCommand) {
+        return Promise.resolve(generateDescribeStacksResponse(command));
+      } else if (command instanceof GetTemplateCommand) {
+        return Promise.resolve({
+          TemplateBody:
+            command.input.StackName === GEN1_CATEGORY_STACK_ID
+              ? JSON.stringify(oldGen1TemplateWithoutS3Bucket)
+              : JSON.stringify(oldGen2Template),
+        });
+      }
+      return Promise.resolve({});
+    };
+    mockCfnClientSendMock.mockImplementationOnce(sendFailureMock).mockImplementationOnce(sendFailureMock);
+    await expect(noGen1ResourcesToMoveS3TemplateGenerator.generateGen1PreProcessTemplate()).rejects.toThrowError();
+  });
 });

packages/amplify-migration-template-gen/src/category-template-generator.ts

@@ -39,6 +39,8 @@ class CategoryTemplateGenerator<CFNCategoryType extends CFN_CATEGORY_TYPE> {
         );
       }),
     );
+    // validate empty resources
+    if (this.gen1ResourcesToMove.size === 0) throw new Error('No resources to move in Gen1 stack.');
     const logicalResourceIds = [...this.gen1ResourcesToMove.keys()];
     const gen1ParametersResolvedTemplate = new CfnParameterResolver(oldGen1Template).resolve(Parameters);
     const gen1TemplateWithOutputsResolved = new CfnOutputResolver(gen1ParametersResolvedTemplate, this.region, this.accountId).resolve(
@@ -58,14 +60,15 @@ class CategoryTemplateGenerator<CFNCategoryType extends CFN_CATEGORY_TYPE> {
     this.gen2DescribeStacksResponse = await this.describeStack(this.gen2StackId);
     assert(this.gen2DescribeStacksResponse);
     const { Parameters, Outputs } = this.gen2DescribeStacksResponse;
-    assert(Parameters);
     assert(Outputs);
     const oldGen2Template = await this.readTemplate(this.gen2StackId);
     this.gen2ResourcesToRemove = new Map(
       Object.entries(oldGen2Template.Resources).filter(([, value]) =>
         this.resourcesToMove.some((resourceToMove) => resourceToMove.valueOf() === value.Type),
       ),
     );
+    // validate empty resources
+    if (this.gen2ResourcesToRemove.size === 0) throw new Error('No resources to remove in Gen2 stack.');
     const updatedGen2Template = this.removeGen2ResourcesFromGen2Stack(oldGen2Template, [...this.gen2ResourcesToRemove.keys()]);
     return {
       oldTemplate: oldGen2Template,

packages/amplify-migration-template-gen/src/index.ts

@@ -0,0 +1 @@
+export * from './template-generator';

packages/amplify-migration-template-gen/src/migration-readme-generator.test.ts

@@ -116,7 +116,8 @@ aws cloudformation update-stack \\
  --stack-name amplify-mygen2app-test-sandbox-12345-auth-ABCDE \\
  --template-body file://test/step2-gen2ResourcesRemovalStackTemplate.json \\
  --parameters '[{"ParameterKey":"authSelections","ParameterValue":"identityPoolAndUserPool"}]' \\
- --capabilities CAPABILITY_NAMED_IAM
+ --capabilities CAPABILITY_NAMED_IAM \\
+ --tags '[]'
  \`\`\`
 
 \`\`\`

packages/amplify-migration-template-gen/src/migration-readme-generator.ts

@@ -94,7 +94,8 @@ aws cloudformation update-stack \\
  --stack-name ${this.gen2CategoryStackName} \\
  --template-body file://${step2FileNamePath} \\
  --parameters '${paramsString}' \\
- --capabilities CAPABILITY_NAMED_IAM
+ --capabilities CAPABILITY_NAMED_IAM \\
+ --tags '[]'
  \`\`\`
 
 \`\`\`

packages/amplify-migration-template-gen/src/resolvers/cfn-condition-resolver.ts

@@ -16,7 +16,7 @@ class CFNConditionResolver {
   public resolve(parameters: Parameter[]) {
     if (!this.conditions || Object.keys(this.conditions).length === 0) return this.template;
 
-    const clonedGen1Template = JSON.parse(JSON.stringify(this.template)) as CFNTemplate;
+    const clonedTemplate = JSON.parse(JSON.stringify(this.template)) as CFNTemplate;
     const conditionValueMap = new Map<string, boolean>();
     Object.entries(this.conditions).forEach(([conditionKey, conditionValue]) => {
       const fnType = Object.keys(conditionValue)[0];
@@ -28,9 +28,9 @@ class CFNConditionResolver {
       }
     });
 
-    this.resolveConditionInResources(clonedGen1Template.Resources, conditionValueMap);
+    this.resolveConditionInResources(clonedTemplate.Resources, conditionValueMap);
 
-    return clonedGen1Template;
+    return clonedTemplate;
   }
 
   private resolveCondition(

packages/amplify-migration-template-gen/src/resolvers/cfn-output-resolver.ts

@@ -23,30 +23,29 @@ class CfnOutputResolver {
     assert(stackTemplateOutputs);
     let stackTemplateResourcesString = JSON.stringify(stackTemplateResources);
 
-    for (const logicalResourceId of logicalResourceIds) {
-      Object.entries(stackTemplateOutputs).forEach(([outputKey, outputValue]) => {
-        const value = outputValue.Value;
-        const stackOutputValue = stackOutputs?.find((op) => op.OutputKey === outputKey)?.OutputValue;
-        assert(stackOutputValue);
+    Object.entries(stackTemplateOutputs).forEach(([outputKey, outputValue]) => {
+      const value = outputValue.Value;
+      const stackOutputValue = stackOutputs?.find((op) => op.OutputKey === outputKey)?.OutputValue;
+      assert(stackOutputValue);
 
-        // Replace logicalId references using stack output values
-        if (typeof value === 'object' && REF in value && value[REF] === logicalResourceId) {
-          const outputRegexp = new RegExp(`{"${REF}":"${logicalResourceId}"}`, 'g');
-          stackTemplateResourcesString = stackTemplateResourcesString.replaceAll(outputRegexp, `"${stackOutputValue}"`);
+      // Replace logicalId references using stack output values
+      if (typeof value === 'object' && REF in value) {
+        const logicalResourceId = value[REF] as string;
+        const outputRegexp = new RegExp(`{"${REF}":"${logicalResourceId}"}`, 'g');
+        stackTemplateResourcesString = stackTemplateResourcesString.replaceAll(outputRegexp, `"${stackOutputValue}"`);
 
-          // Replace Fn:GetAtt references using stack output values
-          const fnGetAttRegExp = new RegExp(`{"${GET_ATT}":\\["${logicalResourceId}","(?<AttributeName>\\w+)"]}`, 'g');
-          const fnGetAttRegExpResult = stackTemplateResourcesString.matchAll(fnGetAttRegExp).next();
-          const resourceType = this.template.Resources[logicalResourceId].Type as CFN_RESOURCE_TYPES;
-          if (!fnGetAttRegExpResult.done) {
-            const attributeName = fnGetAttRegExpResult.value.groups?.AttributeName;
-            assert(attributeName);
-            const resource = this.getResourceAttribute(attributeName as AWS_RESOURCE_ATTRIBUTES, resourceType, stackOutputValue);
-            stackTemplateResourcesString = stackTemplateResourcesString.replaceAll(fnGetAttRegExp, this.buildFnGetAttReplace(resource));
-          }
+        // Replace Fn:GetAtt references using stack output values
+        const fnGetAttRegExp = new RegExp(`{"${GET_ATT}":\\["${logicalResourceId}","(?<AttributeName>\\w+)"]}`, 'g');
+        const fnGetAttRegExpResult = stackTemplateResourcesString.matchAll(fnGetAttRegExp).next();
+        const resourceType = this.template.Resources[logicalResourceId].Type as CFN_RESOURCE_TYPES;
+        if (!fnGetAttRegExpResult.done) {
+          const attributeName = fnGetAttRegExpResult.value.groups?.AttributeName;
+          assert(attributeName);
+          const resource = this.getResourceAttribute(attributeName as AWS_RESOURCE_ATTRIBUTES, resourceType, stackOutputValue);
+          stackTemplateResourcesString = stackTemplateResourcesString.replaceAll(fnGetAttRegExp, this.buildFnGetAttReplace(resource));
         }
-      });
-    }
+      }
+    });
 
     clonedStackTemplate.Resources = JSON.parse(stackTemplateResourcesString);
     Object.entries(clonedStackTemplate.Outputs).forEach(([outputKey]) => {

packages/amplify-migration-template-gen/src/resolvers/cfn-parameter-resolver.ts

@@ -7,7 +7,8 @@ class CfnParameterResolver {
 
   public resolve(parameters: Parameter[]) {
     if (!parameters.length) return this.template;
-    let templateString = JSON.stringify(this.template);
+    const clonedGen1Template = JSON.parse(JSON.stringify(this.template)) as CFNTemplate;
+    let templateString = JSON.stringify(clonedGen1Template);
     const parametersFromTemplate = this.template.Parameters;
     for (const { ParameterKey, ParameterValue } of parameters) {
       assert(ParameterKey);