pass arrays as is

Author: Leon Michalski

packages/aws-cdk-lib/aws-lambda/test/function.test.ts

@@ -5219,6 +5219,61 @@ describe('L1 Relationships', () => {
     });
   });
 
+  it('array reference should be valid', () => {
+    const stack = new cdk.Stack();
+    const role = new iam.Role(stack, 'SomeRole', {
+      assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
+    });
+    const layer1 = new lambda.LayerVersion(stack, 'LayerVersion1', {
+      code: lambda.Code.fromAsset(path.join(__dirname, 'my-lambda-handler')),
+      compatibleRuntimes: [lambda.Runtime.PYTHON_3_13],
+    });
+    const layerArray = [layer1, 'layer2Arn'];
+    new lambda.CfnFunction(stack, 'MyLambda', {
+      code: { zipFile: 'foo' },
+      role: role,
+      layers: layerArray,
+    });
+
+    layerArray.push('layer3Arn');
+
+    Template.fromStack(stack).hasResource('AWS::Lambda::Function', {
+      Properties: {
+        Role: { 'Fn::GetAtt': ['SomeRole6DDC54DD', 'Arn'] },
+        Layers: [{ Ref: 'LayerVersion139D4D7A8' }, 'layer2Arn', 'layer3Arn'],
+      },
+    });
+  });
+
+  it('nested array references should still be valid', () => {
+    const stack = new cdk.Stack();
+    const role = new iam.Role(stack, 'SomeRole', {
+      assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
+    });
+    const securityGroup = new ec2.SecurityGroup(stack, 'SG', {
+      vpc: new ec2.Vpc(stack, 'VPC'),
+    });
+    const vpcConfig = {
+      securityGroupIds: [securityGroup, 'securityGroupArn2'],
+    };
+    new lambda.CfnFunction(stack, 'MyLambda', {
+      code: { zipFile: 'foo' },
+      role: role,
+      vpcConfig,
+    });
+
+    vpcConfig.securityGroupIds.push('securityGroupArn3');
+
+    Template.fromStack(stack).hasResource('AWS::Lambda::Function', {
+      Properties: {
+        Role: { 'Fn::GetAtt': ['SomeRole6DDC54DD', 'Arn'] },
+        VpcConfig: {
+          SecurityGroupIds: [{ 'Fn::GetAtt': ['SGADB53937', 'GroupId'] }, 'securityGroupArn2', 'securityGroupArn3'],
+        },
+      },
+    });
+  });
+
   it('tokens should be passed as is', () => {
     const stack = new cdk.Stack();
     const role = new iam.Role(stack, 'SomeRole', {

tools/@aws-cdk/spec2cdk/lib/cdk/resolver-builder.ts

@@ -93,7 +93,9 @@ export class ResolverBuilder {
     ].join(' ?? ');
     const resolver = (_: Expression) => {
       if (resolvableType.arrayOfType) {
-        return expr.directCode(`props.${name}?.map((item: any) => ${ buildChain('item') })`);
+        return expr.directCode(
+          `(props.${name}?.forEach((item: ${propType.arrayOfType!.toString()}, i: number, arr: ${propType.toString()}) => { arr[i] = ${buildChain('item')}; }), props.${name} as ${resolvableType.toString()})`,
+        );
       } else {
         return expr.directCode(buildChain(`props.${name}`));
       }
@@ -118,11 +120,11 @@ export class ResolverBuilder {
       const isArray = baseType.arrayOfType !== undefined;
 
       const flattenCall = isArray
-        ? propValue.callMethod('map', expr.ident(functionName))
+        ? expr.directCode(`props.${name}.forEach((item: any, i: number, arr: any[]) => { arr[i] = ${functionName}(item) }), props.${name}`)
         : expr.ident(functionName).call(propValue);
 
       const condition = optional
-        ? expr.cond(propValue).then(flattenCall).else(expr.UNDEFINED)
+        ? expr.cond(expr.not(propValue)).then(expr.UNDEFINED).else(flattenCall)
         : flattenCall;
 
       return isArray