chore(cli): improve error message for cdk migrate

packages/aws-cdk/lib/commands/migrate.ts

@@ -82,11 +82,14 @@ export async function generateCdkApp(stackName: string, stack: string, language:
  * @returns A string representation of a CDK stack file
  */
 export function generateStack(template: string, stackName: string, language: string) {
+  const formattedStackName = `${camelCase(decamelize(stackName), { pascalCase: true })}Stack`;
   try {
-    const formattedStackName = `${camelCase(decamelize(stackName), { pascalCase: true })}Stack`;
     return cdk_from_cfn.transmute(template, language, formattedStackName);
   } catch (e) {
-    throw new Error(`stack generation failed due to error '${(e as Error).message}'`);
+    const errorMessage = (e as Error).message === 'unreachable'
+      ? 'template and/or language inputs caused the source code to panic'
+      : (e as Error).message.replace('TransmuteError: ', '');
+    throw new Error(`${formattedStackName} could not be generated because ${errorMessage}`);
   }
 }
 

packages/aws-cdk/package.json

@@ -105,7 +105,7 @@
     "aws-sdk": "^2.1562.0",
     "camelcase": "^6.3.0",
     "cdk-assets": "0.0.0",
-    "cdk-from-cfn": "^0.133.0",
+    "cdk-from-cfn": "^0.140.0",
     "chalk": "^4",
     "chokidar": "^3.6.0",
     "decamelize": "^5.0.1",

packages/aws-cdk/test/commands/migrate.test.ts

@@ -21,7 +21,9 @@ describe('Migrate Function Tests', () => {
 
   const validTemplatePath = path.join(...templatePath, 's3-template.json');
   const emptyTemplatePath = path.join(...templatePath, 'empty-template.yml');
+  const invalidTemplatePath = path.join(...templatePath, 'rds-template.json');
   const validTemplate = readFromPath(validTemplatePath)!;
+  const invalidTemplate = readFromPath(invalidTemplatePath)!;
 
   beforeEach(async () => {
     sdkProvider = new MockSdkProvider();
@@ -132,7 +134,11 @@ describe('Migrate Function Tests', () => {
   });
 
   test('generateStack throws error when called for other language', () => {
-    expect(() => generateStack(validTemplate, 'BadBadBad', 'php')).toThrowError('stack generation failed due to error \'unreachable\'');
+    expect(() => generateStack(validTemplate, 'BadBadBad', 'php')).toThrowError('BadBadBadStack could not be generated because template and/or language inputs caused the source code to panic');
+  });
+
+  test('generateStack throws error for invalid resource property', () => {
+    expect(() => generateStack(invalidTemplate, 'VeryBad', 'typescript')).toThrow('VeryBadStack could not be generated because ReadEndpoint is not a valid property for resource RDSCluster of type AWS::RDS::DBCluster');
   });
 
   cliTest('generateCdkApp generates the expected cdk app when called for typescript', async (workDir) => {

packages/aws-cdk/test/commands/test-resources/templates/rds-template.json

@@ -0,0 +1,18 @@
+{
+  "AWSTemplateFormatVersion": "2010-09-09",
+  "Resources": {
+    "RDSCluster": {
+      "Type": "AWS::RDS::DBCluster",
+      "Properties": {
+        "DBClusterIdentifier" : "aurora-postgresql-cluster",
+        "Engine" : "aurora-postgresql",
+        "EngineVersion" : "10.7",
+        "DBClusterParameterGroupName" : "default.aurora-postgresql10",
+        "EnableCloudwatchLogsExports" : ["postgresql"],
+        "ReadEndpoint": {
+            "Address": "http://127.0.0.1:8080"
+        }
+      }
+    }
+  }
+}

yarn.lock

@@ -6307,10 +6307,10 @@ case@1.6.3, case@^1.6.3:
   resolved "https://registry.npmjs.org/case/-/case-1.6.3.tgz#0a4386e3e9825351ca2e6216c60467ff5f1ea1c9"
   integrity sha512-mzDSXIPaFwVDvZAHqZ9VlbyF4yyXRuX6IvB06WvPYkqJVO24kX1PPhv9bfpKNFZyxYFmmgo03HUiD8iklmJYRQ==
 
-cdk-from-cfn@^0.133.0:
-  version "0.133.0"
-  resolved "https://registry.npmjs.org/cdk-from-cfn/-/cdk-from-cfn-0.133.0.tgz#a18dd2c505c8fc0b7f4947f6d6afb3e7fea5b391"
-  integrity sha512-Yj0kE+GixlSGLNTodCaZEcIeyxzNQonZAykmsSP7wRSm3yYNfg/2XX1tRWi9hzUGMwqYuQr5GsCBymukU0GKsA==
+cdk-from-cfn@^0.140.0:
+  version "0.140.0"
+  resolved "https://registry.npmjs.org/cdk-from-cfn/-/cdk-from-cfn-0.140.0.tgz#c9cbd96f0f559adfbd1874c03f2ac623427ef6b3"
+  integrity sha512-i9RjfOeEZDyKqI2FLbZgxuV5FwDkipv/3AqiSSw3TtLaIWi3qQ17GPrVOekINLqC4OgT7tCiMWawswwrM/sAaQ==
 
 cdk-generate-synthetic-examples@^0.1.304:
   version "0.1.304"