🤖 AI-Powered Test Generation

This release adds AI-powered test case generation using local LLMs via Ollama, enabling automatic generation of intelligent, realistic test cases.

✨ Key Features

• 🧠 Intelligent Test Cases: AI analyzes function implementation to generate realistic test values, edge cases, and error conditions
• 🏠 Local-First & Private: Uses Ollama to run LLMs locally - your code never leaves your machine
• ⚡ Fast Small Models: Default qwen2.5-coder:0.5b model (400MB) generates tests in seconds
• 🎯 Smart Coverage: Automatically identifies edge cases, error conditions, and validation logic
• 🔧 Flexible: Support for simple types, complex types, methods, variadic params, and multiple return values
• 📊 Configurable: Adjust min/max test cases, choose different models, or use custom endpoints

🚀 Quick Start

# Install Ollama (one-time setup)
curl -fsSL https://ollama.com/install.sh | sh
ollama serve &
ollama pull qwen2.5-coder:0.5b

# Generate tests with AI
gotests -all -ai -w yourfile.go

📝 Example

Given this function:

func CalculateDiscount(price float64, percentage int) (float64, error) {
    if price < 0 {
        return 0, errors.New("price cannot be negative")
    }
    if percentage < 0 || percentage > 100 {
        return 0, errors.New("percentage must be between 0 and 100")
    }
    return price - (price * float64(percentage) / 100.0), nil
}

AI generates:

• ✅ Valid input test case
• ✅ Negative price error case
• ✅ Invalid percentage error case
• ✅ Proper error handling and assertions

🎛️ Configuration Options

# Use different model
gotests -all -ai -ai-model llama3.2:latest -w file.go

# Generate specific number of test cases (min = max)
gotests -all -ai -ai-min-cases 5 -ai-max-cases 5 -w file.go

# Generate range of test cases (AI chooses 3-7)
gotests -all -ai -ai-min-cases 3 -ai-max-cases 7 -w file.go

# Custom Ollama endpoint
gotests -all -ai -ai-endpoint http://custom:11434 -w file.go

🔒 Privacy & Security

• ✅ Local-first by default - Using Ollama keeps all data on your machine
• ✅ Offline operation - Works completely offline with local models
• ⚠️ Function bodies are analyzed - Business logic and code comments are sent to the LLM
• 🔒 Recommendation: Avoid using -ai on code containing secrets or API keys

📊 Test Coverage Improvements

• Increased overall project coverage from 28.1% to 84.6% (#196)
• Added comprehensive tests for:
  • internal/goparser package
  • internal/models package
  • internal/output package
  • internal/render package
  • gotests/process package

📚 Documentation Enhancements

• Added godoc comments to all exported functions (#195)
• Expanded README with:
  • AI-powered test generation section
  • Quick start examples
  • Privacy and security considerations
  • Configuration options and examples

🛠️ Technical Implementation

New Packages:

• internal/ai - AI provider abstraction layer
  • Ollama provider with health checks and retries
  • Go-specific prompt engineering
  • Response parsing and validation
  • E2E test suite with golden file validation

CLI Flags:

• -ai - Enable AI test case generation
• -ai-model - Select model (default: qwen2.5-coder:0.5b)
• -ai-endpoint - Ollama endpoint (default: http://localhost:11434)
• -ai-min-cases - Minimum test cases to generate (default: 3)
• -ai-max-cases - Maximum test cases to generate (default: 10)

Architecture:

• Provider-based design for future LLM support
• Language-agnostic core with Go-specific implementation
• Graceful fallback to TODO comments on generation failure
• Integration with existing template rendering pipeline

🐛 Known Issues

• Issue #197: 4 out of 11 E2E tests disabled due to environment-dependent LLM non-determinism
  • Does not affect functionality, only E2E test validation
  • 7 E2E tests pass consistently on first attempt
  • Will be addressed in future patch release

📦 Installation

go install github.com/cweill/gotests/[email protected]

🙏 Credits

🤖 Developed with assistance from Claude Code

Full Changelog: v1.8.0...v1.9.0

🎉 Full Go Generics Support

This release adds complete support for Go generics (type parameters), enabling gotests to generate tests for generic functions and methods on generic types.

✨ Key Features

• 🔧 Generic Functions: Generate tests for functions with type parameters

  func FindFirst[T comparable](slice []T, target T) (int, error)

• 🏗️ Generic Types: Support for methods on generic types

  type Set[T comparable] struct { ... }
  func (s *Set[T]) Add(v T)

• 🎯 All Constraint Types: any, comparable, union types (int64 | float64), approximation (~int)

• 🧠 Smart Type Mapping: Intelligent defaults for type instantiation

  • any → int
  • comparable → string
  • Union types → first option
  • Approximation → underlying type

• 🔄 Multiple Type Parameters: Handles functions like Pair[T, U any]

📊 Test Coverage

• ✅ 97.5% main package coverage
• ✅ 83.5% overall project coverage
• ✅ 100% coverage on all new parser functions
• ✅ 8 comprehensive generic test patterns

🔧 Technical Improvements

Parser Enhancements:

• New parseTypeDecls() extracts type parameters from type declarations
• New parseTypeParams() parses AST field lists
• New extractBaseTypeName() handles receiver types

Template Functions:

• TypeArgs - generates concrete type arguments for calls
• FieldType - substitutes type parameters in field declarations
• ReceiverType - substitutes type parameters in receiver instantiations

Model Updates:

• New TypeParam struct
• Added TypeParams field to Function
• Helper methods: IsGeneric(), HasGenericReceiver()

📚 Documentation

Added comprehensive "Go Generics Support" section to README with:

• Example: Generic function test generation
• Example: Methods on generic types
• Type constraint mapping reference

🐛 Fixes

Closes #165

📦 Installation

go install github.com/cweill/gotests/[email protected]

🙏 Credits

🤖 Developed with assistance from Claude Code

Full Changelog: v1.7.0...v1.8.0

What's New in v1.7.4

This release fixes two important bugs that improve test correctness and restore broken functionality.

Bug Fixes

🐛 Fixed wantErr Test Logic (PR #169)

When a test expects an error (tt.wantErr == true), gotests now correctly skips result validation instead of checking potentially undefined return values.

Before:

if (err != nil) != tt.wantErr {
    t.Errorf("Foo() error = %v, wantErr %v", err, tt.wantErr)
    continue
}
// Bug: Still checks results even when error is expected!
if got != tt.want {
    t.Errorf("Foo() = %v, want %v", got, tt.want)
}

After:

if (err != nil) != tt.wantErr {
    t.Errorf("Foo() error = %v, wantErr %v", err, tt.wantErr)
    continue
}
if tt.wantErr {
    return  // ← Fixed: Skip result checks when error expected
}
if got != tt.want {
    t.Errorf("Foo() = %v, want %v", got, tt.want)
}

This prevents false test failures and ensures tests behave correctly when expecting errors.

Thanks to @arifmahmudrana for identifying this issue!

🐛 Fixed -template_params Flag (Issue #149)

The -template_params flag was defined but never actually used due to a bug from PR #90. This flag now works correctly!

Usage:

# Pass template parameters as JSON string
$ gotests -template_params '{"key":"value"}' -all file.go

# Or use a file (takes precedence)
$ gotests -template_params_file params.json -all file.go

This is useful when calling gotests from other tools with custom templates.

Thanks to @butuzov for identifying this bug and @cweill for the fix suggestion!

Installation

go install github.com/cweill/gotests/[email protected]

Full Changelog: v1.7.3...v1.7.4

What's New in v1.7.3

This is a security update that addresses multiple CVEs by updating dependencies.

Security Fixes

🔒 Updated golang.org/x/tools to fix CVEs

Updated golang.org/x/tools from v0.0.0-20191109212701 (November 2019) to v0.38.0 (latest) to address multiple security vulnerabilities:

• CVE-2021-38561 - Fixed
• CVE-2019-9512 - Fixed
• CVE-2020-29652 - Fixed

Changes

• Updated golang.org/x/tools from 2019 version to v0.38.0
• Updated Go directive to 1.24.0 (with toolchain go1.24.5)
• Added indirect dependencies: golang.org/x/mod v0.29.0, golang.org/x/sync v0.17.0
• Fixed test code compatibility with stricter format string checking in newer x/tools

All tests pass with the updated dependencies.

Installation

go install github.com/cweill/gotests/[email protected]

Important Note

We recommend all users update to this version to ensure you have the latest security fixes.

Full Changelog: v1.7.2...v1.7.3

Thanks to @testwill for identifying these security vulnerabilities!

What's New in v1.7.2

This is a small cleanup release with code quality improvements and documentation updates.

Improvements

🧹 Code Cleanup

• Remove unnecessary type conversion (#170) - Simplified code in generateTest() by removing redundant type conversion. Thanks to @fengxuway!

📚 Documentation

• Update VS Code link (#167) - Changed Visual Studio Code link to point directly to gotests-specific configuration documentation for easier setup. Thanks to @davidhsingyuchen!

Installation

go install github.com/cweill/gotests/[email protected]

Full Changelog: v1.7.1...v1.7.2

What's New in v1.7.1

This release adds two highly-requested features to improve the gotests experience.

New Features

🧪 go-cmp Support (-use_go_cmp)

Generate tests using google/go-cmp instead of reflect.DeepEqual for better test assertions and diff output.

$ gotests -use_go_cmp -all -w example.go

Generated tests will use cmp.Equal() for comparisons and cmp.Diff() in error messages, providing much clearer output when tests fail.

Example output:

if !cmp.Equal(tt.want, got) {
    t.Errorf("Foo() = %v, want %v\ndiff=%s", got, tt.want, cmp.Diff(tt.want, got))
}

Resolves #155 (thanks to @butuzov for the original PR!)

📋 Version Information (-version)

Check which version of gotests you're running:

$ gotests -version
gotests v1.7.1
Go version: go1.22.0
Git commit: 5252e0b...
Build time: 2025-10-21T02:15:00Z

This helps with troubleshooting and verifying you have the latest release.

Resolves #133

Housekeeping

• Closed superseded README PRs (#172, #166) that were already addressed in v1.7.0

Installation

go install github.com/cweill/gotests/[email protected]

Full Changelog: v1.7.0...v1.7.1

v1.7.0 - Major Modernization Release

After 5 years since v1.6.0, we're excited to release v1.7.0 with major improvements and modernizations! 🎉

✨ New Features

Recursive Directory Support

You can now generate tests for entire directory trees using the ... pattern:

gotests -all pkg/...

This will recursively generate tests for all Go files in the pkg directory and its subdirectories. Fixes #186.

Cleaner Generated Code

Generated tests now use Go 1.22+ loop variable scoping, eliminating the need for the tt := tt shadowing pattern. Tests are now cleaner and more readable.

Better Error Handling

Subtests with return values now use t.Fatalf() instead of t.Errorf() + return, providing clearer test failure semantics and preventing misleading output. Thanks to PR #184.

🔧 Improvements

BREAKING: Minimum Go Version

• Minimum Go version increased from 1.6 to 1.22
• Leverages modern Go features for cleaner generated code
• Aligns with Go's official support policy

Dependency Reduction

• Replaced third-party bindata tools with stdlib embed package (PR #181)
• Removed 834+ lines of generated code
• Simplified build process - no more go generate needed
• Better maintainability and reduced external dependencies

Bug Fixes

• Fixed import path bug when receiver types and methods are in different files (PR #179)
• Now correctly collects imports from all files in the package
• Prevents compilation errors in generated test files

Template Improvements

• Proper t.Parallel() placement at top-level test functions (fixes #188)
• Satisfies tparallel linter requirements
• Better parallel test execution

Documentation & Installation

• Updated README to use go install instead of deprecated go get (PR #180)
• Documented the -named flag for map-based table tests (PR #185)
• Added CHANGELOG.md for tracking changes
• Added CLAUDE.md for AI-assisted development

📦 CI/CD Updates

• Updated GitHub Actions to test Go 1.22.x, 1.23.x, 1.24.x, and 1.25.x
• Modernized actions: setup-go v2→v5, checkout v2→v4
• Simplified coverage reporting with coverallsapp/github-action@v2
• Fixed bot commit support for automated workflows

📊 Statistics

• 834+ lines of generated bindata code removed
• 5 PRs integrated
• 2 issues fixed
• 4 Go versions tested in CI (was 8, now focused on recent versions)

🙏 Thanks

Special thanks to the contributors whose PRs were integrated in this release:

• PR #184 (t.Fatalf improvement)
• PR #185 (documentation)
• PR #180 (go install)
• PR #181 (embed package)
• PR #179 (import fix)

And to everyone who reported issues and helped maintain this project!

📝 Installation

go install github.com/cweill/gotests/gotests@latest

🔗 Full Changelog

See CHANGELOG.md for complete details.