Test Generation

Introduction

The Test Generation feature uses AI to analyze your code and generate appropriate test cases. It works with your existing test framework, follows your project's patterns, and covers happy paths, edge cases, and error handling.

Key Features

• Framework Detection — Automatically detects PHPUnit, Pest, Jest, pytest, and more
• Pattern Matching — Follows your existing test conventions
• Comprehensive Coverage — Happy path, edge cases, and error handling
• One-Click Apply — Apply generated tests directly to your codebase
• Multi-Platform — Available via slash command, CLI, and VS Code

Using the Slash Command

The quickest way to generate tests is via the /revio test slash command on a pull request.

Basic Usage

Comment on any PR to generate tests for the changed code:

@revio test

Jasper will analyze all changed files in the PR and generate appropriate tests.

Targeting Specific Code

You can focus test generation on specific files or functions:

@revio test UserController

@revio test src/Services/PaymentService.php

Generated Output

Jasper posts the generated tests as a comment with:

• Test file path
• List of generated test cases
• Full test code with syntax highlighting
• Apply button to commit the tests

CLI Usage

Generate tests locally using the Revio CLI.

Installation

npm install -g @revio/cli

Basic Commands

Command	Description
revio test	Generate tests for staged changes
revio test --all	Generate tests for all uncommitted changes
revio test --file path/to/file.php	Generate tests for a specific file
revio test --function methodName	Generate tests for a specific function

Options

Option	Description
--framework <name>	Override framework detection
--format <type>	Output format: table, json, markdown
--apply	Apply tests directly to filesystem
--dry-run	Preview without writing files
--include-patterns	Analyze existing tests for patterns

Example Output

$ revio test --file src/Services/UserService.php

Generated 8 tests

tests/Unit/Services/UserServiceTest.php (NEW)
+------------------------------------------+--------+----------+
| Test Case                                | Type   | Coverage |
+------------------------------------------+--------+----------+
| test_create_user_with_valid_data         | Happy  | create() |
| test_create_user_with_empty_email        | Edge   | create() |
| test_create_user_with_invalid_email      | Error  | create() |
| test_create_user_hashes_password         | Happy  | create() |
| test_find_user_by_id_returns_user        | Happy  | find()   |
| test_find_user_by_id_returns_null        | Edge   | find()   |
| test_update_user_validates_fields        | Error  | update() |
| test_delete_user_soft_deletes            | Happy  | delete() |
+------------------------------------------+--------+----------+

Framework: Pest (detected from composer.json)

Run with --apply to write test files

VS Code Integration

Generate tests directly from VS Code using the Revio extension.

Commands

Command	Keybinding	Description
Revio: Generate Tests	Cmd+Shift+T	Generate tests for current file
Revio: Generate Tests for Selection	—	Generate tests for selected code
Revio: Generate Tests for Function	—	Generate tests for function at cursor

Context Menu

Right-click in the editor to access test generation:

• Revio: Generate Tests for File
• Revio: Generate Tests for Function
• Revio: Generate Tests for Selection

Preview Panel

Generated tests appear in a preview panel where you can:

• Review individual test cases
• View the full test code
• Apply all tests to your workspace
• Copy code to clipboard

Supported Frameworks

Test generation supports major testing frameworks across popular languages:

Language	Framework	File Pattern
PHP	PHPUnit	tests/*Test.php
PHP	Pest	tests/*.php
JavaScript	Jest	*.test.js, __tests__/*.js
TypeScript	Jest/Vitest	*.test.ts, *.spec.ts
Python	pytest	test_*.py, *_test.py
Go	testing	*_test.go
Ruby	RSpec	*_spec.rb
Ruby	Minitest	*_test.rb

Test Coverage Types

Generated tests cover multiple scenarios:

Happy Path

Tests for normal, successful execution:

• Valid inputs produce expected outputs
• State changes occur correctly
• Return values match expectations

Edge Cases

Tests for boundary conditions:

• Empty inputs (empty strings, arrays, null)
• Boundary values (zero, max int, min int)
• Special characters and encoding
• Large inputs

Error Cases

Tests for error handling:

• Invalid input validation
• Exception throwing
• Error state handling
• Authorization failures

Mock Verification

Tests for dependency interactions:

• External service calls
• Database operations
• API interactions
• Event dispatching

Framework Detection

Jasper automatically detects your test framework by analyzing:

• composer.json for PHP (PHPUnit, Pest)
• package.json for JS/TS (Jest, Vitest, Mocha)
• requirements.txt for Python (pytest)
• go.mod for Go
• Gemfile for Ruby (RSpec, Minitest)
• Existing test file patterns in your project

Pattern Analysis

When generating tests, Jasper analyzes your existing tests to match:

• Naming Conventions — test_*, it_*, or descriptive names
• Structure — Class-based or function-based tests
• Assertions — Your preferred assertion style
• Setup/Teardown — Fixtures and before/after hooks
• Mocking — Mock library and patterns

Applying Generated Tests

Via Slash Command

Click the Apply button on the generated test comment. Jasper will commit the test files directly to your PR branch.

Via CLI

revio test --apply

This writes the test files to your local filesystem.

Via VS Code

Click Apply All Tests in the preview panel to write files to your workspace.

Configuration

Repository Settings

Configure test generation per repository in Repository Settings → Test Generation:

Setting	Description
Framework	Override auto-detected framework
Test Directory	Custom test directory path
Exclude Patterns	Files to skip during generation
Custom Instructions	Additional context for AI

VS Code Settings

{
  "revio.testGeneration.enabled": true,
  "revio.testGeneration.framework": "auto",
  "revio.testGeneration.includeEdgeCases": true,
  "revio.testGeneration.includeErrorCases": true,
  "revio.testGeneration.includeMocks": true,
  "revio.testGeneration.autoApply": false
}

Best Practices

• Review Generated Tests — Always review tests before committing; AI may miss domain-specific logic
• Run Tests Locally — Verify generated tests pass before pushing
• Use Existing Patterns — Enable pattern analysis for consistent test style
• Add Custom Instructions — Provide context about your domain or conventions
• Target Specific Code — Generate tests for specific files/functions for better results

Troubleshooting

Wrong Framework Detected

If the wrong framework is detected:

• Use --framework flag to override
• Configure framework in repository settings
• Ensure package files have correct dependencies

Tests Don't Match Project Style

• Enable --include-patterns for pattern analysis
• Add custom instructions in repository settings
• Provide more existing tests as examples

Tests Fail to Run

• Check imports and namespaces are correct
• Verify mock dependencies are available
• Ensure test directory is correct