Fix CloudWatch Logs permissions and add comprehensive testing helpers

[ncipollina]

Summary

• Fixed CloudWatch Logs policy to use full function name with suffix
• Added comprehensive testing helpers for library consumers
• Enhanced documentation and examples

Changes Made

🐛 Bug Fixes

• Fixed CloudWatch Logs IAM policy: Resource ARNs now correctly include function suffix (function-name-suffix instead of just function-name)
• Updated existing tests: Modified tests to match the corrected CloudWatch permissions pattern

✨ New Features

• Testing Helpers Package: Added comprehensive testing infrastructure in src/LayeredCraft.Cdk.Constructs/Testing/:
  • CdkTestHelper: Utilities for creating test stacks and resolving asset paths
  • LambdaFunctionConstructAssertions: Extension methods for CDK template assertions
  • LambdaFunctionConstructPropsBuilder: Fluent builder for creating test props with AWS service integrations

📚 Documentation Updates

• README.md: Added comprehensive testing section with examples and assertion method documentation
• CLAUDE.md: Updated with testing infrastructure details and critical CDK template creation patterns
• Examples: Added examples showing correct CDK template creation timing

🧪 Test Coverage

Added comprehensive test coverage for:

• ShouldHaveEnvironmentVariables and ShouldHaveLambdaPermissions assertion methods
• WithS3Access, WithCustomPolicy, WithCustomPermission builder methods
• GetTestAssetPath and GetTestLambdaZipPath utility methods

Testing Helpers Usage

// Create test infrastructure
var stack = CdkTestHelper.CreateTestStackMinimal();

// Build test props with fluent API
var props = CdkTestHelper.CreatePropsBuilder()
    .WithFunctionName("my-api")
    .WithDynamoDbAccess("users-table")
    .WithApiGatewayPermission("arn:aws:execute-api:us-east-1:123456789012:abc/prod/GET/users")
    .Build();

// Create construct and template
_ = new LambdaFunctionConstruct(stack, "TestLambda", props);
var template = Template.FromStack(stack); // CRITICAL: Create template AFTER construct

// Use assertion helpers
template.ShouldHaveLambdaFunction("my-api-test");
template.ShouldHaveCloudWatchLogsPermissions("my-api-test");
template.ShouldHaveEnvironmentVariables(expectedVars);

Test Plan

• All existing tests pass
• New testing helper methods are fully tested
• CloudWatch Logs permissions fixed and verified
• Documentation examples are accurate
• CDK template creation timing is correct

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR fixes the CloudWatch Logs IAM policy to include function suffixes and adds a rich set of testing helpers with comprehensive documentation and examples.

• Corrected the CloudWatch Logs policy resource ARNs to use full function name plus suffix
• Introduced testing infrastructure (CdkTestHelper, assertion extensions, props builder) and updated tests
• Enhanced README and CLAUDE.md with usage examples and documentation of new helpers

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/LayeredCraft.Cdk.Constructs/Constructs/LambdaFunctionConstruct.cs	Updated log policy ARNs to include FunctionSuffix
src/LayeredCraft.Cdk.Constructs/Testing/	Added CdkTestHelper, LambdaFunctionConstructPropsBuilder, and LambdaFunctionConstructAssertions
test/LayeredCraft.Cdk.Constructs.Tests/Testing/TestingHelpersTests.cs	New tests for the testing helpers
test/LayeredCraft.Cdk.Constructs.Tests/TestKit/Extensions/AssetPathExtensions.cs	Added asset‐path resolution extensions
README.md	Documented new testing support
CLAUDE.md	Updated instructions and helper docs

Comments suppressed due to low confidence (6)

test/LayeredCraft.Cdk.Constructs.Tests/TestKit/Extensions/AssetPathExtensions.cs:1

• AssetPathExtensions uses Path.Combine and Path.GetDirectoryName but doesn’t import System.IO. Add using System.IO; to the top of this file so that Path is resolved correctly.

using System.Reflection;

src/LayeredCraft.Cdk.Constructs/Testing/CdkTestHelper.cs:1

• CdkTestHelper calls Path.GetDirectoryName and Path.Combine but lacks using System.IO;. Add that import to avoid compilation errors.

using System.Reflection;

src/LayeredCraft.Cdk.Constructs/Testing/LambdaFunctionConstructPropsBuilder.cs:1

• This builder uses List<T> and Dictionary<TKey, TValue> but doesn’t import System.Collections.Generic. Add using System.Collections.Generic; at the top.

using Amazon.CDK.AWS.IAM;

src/LayeredCraft.Cdk.Constructs/Testing/LambdaFunctionConstructAssertions.cs:1

• This assertions class builds Dictionary<string, object> instances but lacks using System.Collections.Generic;. Add that import to ensure the generic types resolve.

using Amazon.CDK.Assertions;

test/LayeredCraft.Cdk.Constructs.Tests/Testing/TestingHelpersTests.cs:1

• TestingHelpersTests calls Path.IsPathRooted but doesn’t import System.IO. Add using System.IO; so Path is recognized.

using Amazon.CDK.Assertions;

test/LayeredCraft.Cdk.Constructs.Tests/Testing/TestingHelpersTests.cs:2

• This test file constructs Dictionary<string, string> but doesn’t import System.Collections.Generic. Add using System.Collections.Generic; to avoid errors.

using AwesomeAssertions;