BAML Source Files

This directory contains the BAML source files used by all integration tests. It defines the clients, generators, and test cases that are used across all language implementations.

Directory Structure

baml_src/
├── clients.baml         # Main client definitions
├── generators.baml      # Generator functions
├── test-files/         # Test-specific BAML files
│   ├── providers/      # Provider-specific tests
│   ├── testing_pipeline/ # Pipeline test cases
│   └── ...
├── formatter/          # Formatter-specific tests
└── fiddle-examples/    # Example BAML files for testing

Adding New Tests

1. Client Tests

Add new client tests in clients.baml:

baml

client<llm> TestGPT {
  provider openai
  retry_policy TestRetry
  options {
    model gpt-4
    api_key env.OPENAI_API_KEY
  }
}

retry_policy TestRetry {
  max_retries 3
  strategy {
    type exponential_backoff
  }
}

2. Provider Tests

Add provider-specific tests in test-files/providers/:

baml

// 1. First, define your client
client<llm> TestAnthropic {
  provider anthropic
  options {
    model claude-3-haiku-20240307
    api_key env.ANTHROPIC_API_KEY
    max_tokens 1000
  }
}

// 2. Create a function that uses the client
function TestAnthropicCompletion(input: string) -> string {
  client TestAnthropic
  prompt #"""
    Respond to this input with a simple response.

    Input: {{input}}
  """#
}

// 3. Create a test for the function
test TestAnthropicCompletion {
  functions [TestAnthropicCompletion]
  args {
    input #"What is the capital of France?"#
  }
  assert response == "Paris"
}

// You can also test error cases
function TestAnthropicError(input: string) -> string {
  client TestAnthropic
  prompt #"""
    This is a test for error handling.
    {{input}}
  """#
}

test TestAnthropicError {
  functions [TestAnthropicError]
  args {
    input #"Test input"#
  }
  expect_error true
}

Using Generators

Generators in generators.baml are used to define language-specific output:

baml

generator lang_typescript {
  output_type typescript
  output_dir "../typescript"
  version "0.72.0"
}

generator lang_python {
  output_type python/pydantic
  output_dir "../python"
  version "0.72.0"
}

generator lang_ruby {
  output_type ruby/sorbet
  output_dir "../ruby"
  version "0.72.0"
}

Test Categories

Provider Tests
- Located in test-files/providers/
- Test specific provider implementations (OpenAI, Anthropic, etc.)
- Each provider has its own BAML file
Pipeline Tests
- Located in test-files/testing_pipeline/
- Test BAML pipeline functionality
- Include chain tests, fallback tests, etc.
Formatter Tests
- Located in formatter/
- Test BAML's formatting capabilities
- Include structured output tests

Best Practices

Organizing Tests
- Group related tests in the same file
- Use descriptive names for test functions
- Add comments explaining test purpose
Writing Test Cases
- Test both success and failure cases
- Include validation rules
- Test edge cases and error handling
Using Generators
- Define output types for each language
- Specify correct output directories
- Maintain version consistency
Adding New Providers
- Create new file in test-files/providers/
- Test provider-specific features
- Include authentication tests

Common Patterns

Fallback Testing

baml

client<llm> Resilient {
  provider baml-fallback
  options {
    strategy [
      GPT4
      GPT35
      Claude
    ]
  }
}

Round-Robin Testing

baml

client<llm> RoundRobin {
  provider baml-round-robin
  options {
    start 0
    strategy [
      GPT35
      Claude
    ]
  }
}

Retry Policies

baml

retry_policy TestRetry {
  max_retries 3
  strategy {
    type exponential_backoff
  }
}

client<llm> RetryTest {
  provider openai
  retry_policy TestRetry
  options {
    model gpt-4
    api_key env.OPENAI_API_KEY
  }
}