make-unit-tests

name	make-unit-tests
description	Generate comprehensive unit tests in Go with 100% coverage following specific structural standards. Use when prompted "add unit tests", "add new unit tests", "test this code", "test this", "make unit test", "make test"

Go Unit Test Generation Skill

🎯 Objective

Analyze a given Go file and generate a complete unit test file following Go standard practices, ensuring maximum resilience and aiming for 100% test coverage.

📂 File Structure Guidelines

• One test file per source file: Generate a single *_test.go file for each analyzed source file.
• Naming Convention: The file name must match the analyzed file with the suffix _test.go (e.g., service.go -> service_test.go).
• Namespace/Package: Use the same package name as the analyzed file appended with _test (e.g., if package is user, use package user_test) to ensure black-box testing.

🎯 Coverage & Validation Specifications

• Target Coverage: Ensure your test scenarios cover 100% of the lines of code present in the target module.
• Thorough Validation: Validate all input parameters and output values for each method and function.
• Path Verification: Include test cases that validate both Success and Failure scenarios.

🛑 Constraints & Rules

• Allowed Packages: Use ONLY the standard library testing package. Do NOT import the reflect package or external mocking libraries unless configured.
• Scope Limitation: Utilize only the structs and functions that are present natively in the analyzed file. Do not generate extraneous tests.
• Clean Imports: Keep imports strictly to what is necessary for the tests.
• Code Preservation: Do not rewrite existing structs or functions. Your sole objective is executing and testing them.

🏗️ Test Structure Implementation

Each tested method or function must have one primary test method that groups all cases securely.

Test Organization

1. Use t.Run() for defining individual sub-test cases.
2. Every sub-test case must begin with t.Parallel() to enable parallel execution.
3. Use t.Cleanup() appropriately for resource sanitization, teardown, or channel closing.

Example Reference Structure

func TestPointToPoint_Send(t *testing.T) {
	t.Run("should send message successfully", func(t *testing.T) {
		t.Parallel()
		msg := &message.Message{}
		ctx := context.Background()
		ch := channel.NewPointToPointChannel("chan1")
		go ch.Send(ctx, msg)
		ch.Receive()
		t.Cleanup(func() {
			ch.Close()
		})
	})

	t.Run("should error when send message with context cancel", func(t *testing.T) {
		t.Parallel()
		ch := channel.NewPointToPointChannel("chan1")
		msg := &message.Message{}
		ctx, cancel := context.WithCancel(context.Background())
		cancel()
		err := ch.Send(ctx, msg)
		if err.Error() != "context cancelled while sending message: context canceled" {
			t.Errorf("Send should return nil error, got: %v", err)
		}
		t.Cleanup(func() {
			ch.Close()
		})
	})

	t.Run("should return error if channel has been closed", func(t *testing.T) {
		t.Parallel()
		ch := channel.NewPointToPointChannel("chan1")
		msg := &message.Message{}
		ctx := context.Background()
		ch.Close()
		err := ch.Send(ctx, msg)
		if err.Error() != "channel has not been opened" {
			t.Error("Send should return error if channel is closed")
		}
	})
}