From 819888470248fed2ddbdac689f14254688eef88f Mon Sep 17 00:00:00 2001
From: Pahud Hsieh <pahudnet@gmail.com>
Date: Fri, 12 Apr 2024 17:31:37 -0400
Subject: [PATCH] fix(lambda): version.fromVersionArn creates invalid Version
 object (#29820)

### Issue # (if applicable)

Closes https://github.com/aws/aws-cdk/issues/29813

### Reason for this change

improve the fromFunctionArn()  to better handle the input ARN

### Description of changes

fromFunctionArn() does not handle the ARN correctly if the input ARN has trailing version or alias.

### Description of how you validated changes

See unit tests

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*
---
 .../aws-cdk-lib/aws-lambda/lib/function.ts    | 13 +++++++++-
 .../aws-lambda/test/function.test.ts          | 24 +++++++++++++++++++
 .../aws-lambda/test/lambda-version.test.ts    |  3 +++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/packages/aws-cdk-lib/aws-lambda/lib/function.ts b/packages/aws-cdk-lib/aws-lambda/lib/function.ts
index dba046f447513..3f784a5ccc247 100644
--- a/packages/aws-cdk-lib/aws-lambda/lib/function.ts
+++ b/packages/aws-cdk-lib/aws-lambda/lib/function.ts
@@ -671,7 +671,18 @@ export class Function extends FunctionBase {
    * in the same account and region as the stack you are importing it into.
    */
   public static fromFunctionArn(scope: Construct, id: string, functionArn: string): IFunction {
-    return Function.fromFunctionAttributes(scope, id, { functionArn });
+    /**
+     * If the functionArn has a trailing version or alias (more than 7 parts when split by ":",
+     * we trim off the trailing version/alias to retrieve the real functionArn.
+     * See lambda resource ARN format here: https://docs.aws.amazon.com/lambda/latest/dg/lambda-api-permissions-ref.html
+     */
+    const parts = functionArn.split(':');
+    if (parts.length > 7) {
+      const _functionArn = parts.slice(0, 7).join(':');
+      return Function.fromFunctionAttributes(scope, id, { functionArn: _functionArn });
+    } else {
+      return Function.fromFunctionAttributes(scope, id, { functionArn });
+    }
   }
 
   /**
diff --git a/packages/aws-cdk-lib/aws-lambda/test/function.test.ts b/packages/aws-cdk-lib/aws-lambda/test/function.test.ts
index f4c5382707641..7711c3ff0fed3 100644
--- a/packages/aws-cdk-lib/aws-lambda/test/function.test.ts
+++ b/packages/aws-cdk-lib/aws-lambda/test/function.test.ts
@@ -397,6 +397,30 @@ describe('function', () => {
     expect(imported.functionName).toEqual('ProcessKinesisRecords');
   });
 
+  test('fromFunctionArn with verionArn as the input', () => {
+    // GIVEN
+    const stack2 = new cdk.Stack();
+
+    // WHEN
+    const imported = lambda.Function.fromFunctionArn(stack2, 'Imported', 'arn:aws:lambda:us-east-1:123456789012:function:ProcessKinesisRecords:1');
+
+    // THEN
+    expect(imported.functionArn).toEqual('arn:aws:lambda:us-east-1:123456789012:function:ProcessKinesisRecords');
+    expect(imported.functionName).toEqual('ProcessKinesisRecords');
+  });
+
+  test('fromFunctionArn with trailing alias as the input', () => {
+    // GIVEN
+    const stack2 = new cdk.Stack();
+
+    // WHEN
+    const imported = lambda.Function.fromFunctionArn(stack2, 'Imported', 'arn:aws:lambda:us-east-1:123456789012:function:ProcessKinesisRecords:TEST');
+
+    // THEN
+    expect(imported.functionArn).toEqual('arn:aws:lambda:us-east-1:123456789012:function:ProcessKinesisRecords');
+    expect(imported.functionName).toEqual('ProcessKinesisRecords');
+  });
+
   test('Function.fromFunctionName', () => {
     // GIVEN
     const stack = new cdk.Stack();
diff --git a/packages/aws-cdk-lib/aws-lambda/test/lambda-version.test.ts b/packages/aws-cdk-lib/aws-lambda/test/lambda-version.test.ts
index 6236a92df5dae..3356fa2dbf400 100644
--- a/packages/aws-cdk-lib/aws-lambda/test/lambda-version.test.ts
+++ b/packages/aws-cdk-lib/aws-lambda/test/lambda-version.test.ts
@@ -15,6 +15,9 @@ describe('lambda version', () => {
     // WHEN
     const version = lambda.Version.fromVersionArn(stack, 'Version', 'arn:aws:lambda:region:account-id:function:function-name:version');
 
+    expect(version.version).toStrictEqual('version');
+    expect(version.lambda.functionArn).toStrictEqual('arn:aws:lambda:region:account-id:function:function-name');
+
     new cdk.CfnOutput(stack, 'ARN', { value: version.functionArn });
     new cdk.CfnOutput(stack, 'Name', { value: version.functionName });