---
title: "Test Implementation: AdapterRegistry.get() Exception Handling (Issue #601)"
by: "khive-implementer"
created: "2025-04-22"
updated: "2025-04-22"
version: "1.0"
doc_type: "TI"
output_subdir: "tis"
description: "Test Implementation Plan for verifying the change in AdapterRegistry.get() to raise MissingAdapterError."
date: "2025-04-22"
---

# Guidance

**Purpose** Document the planned and actual test implementation. Clarify unit,
integration, performance, mocking details, and test data.

**When to Use**

- Before/during writing tests, especially if it’s a large feature or
  microservice.
- As a blueprint to ensure coverage is complete.

**Best Practices**

- Keep tests short and focused.
- Use mocking for external calls.
- Outline coverage goals.

---

# Test Implementation Plan: AdapterRegistry.get() Exception Handling (Issue #601)

## 1. Overview

### 1.1 Component Under Test

The primary component under test is the `AdapterRegistry` class, specifically
its `get()` method.

### 1.2 Test Approach

This implementation focuses on **Unit Tests** to verify the specific behavior
change in `AdapterRegistry.get()`. Existing integration tests will implicitly
verify that downstream call-sites handle the new exception correctly.

### 1.3 Key Testing Goals

- Verify that `AdapterRegistry.get()` raises a `MissingAdapterError` when an
  unknown adapter key is provided.
- Ensure that the existing functionality of `AdapterRegistry.get()` for
  retrieving registered adapters remains unchanged.

## 2. Test Environment

### 2.1 Test Framework

```
pytest
pytest-asyncio
pytest-mock
pytest-cov
```

### 2.2 Mock Framework

```
unittest.mock
pytest-mock
```

### 2.3 Test Database

Not applicable for this issue.

## 3. Unit Tests

### 3.1 Test Suite: AdapterRegistry

#### 3.1.1 Test Case: get() - Unknown Key Raises MissingAdapterError

**Purpose:** To verify that calling `AdapterRegistry.get()` with a key that has
not been registered results in a `MissingAdapterError` being raised, as
specified in Issue #601.

**Setup:**

Import necessary modules: `pytest`, `AdapterRegistry`, `MissingAdapterError`.
Instantiate an empty `AdapterRegistry`.

**Test Implementation:**

```python
import pytest
from lionagi._class_registry import AdapterRegistry
from lionagi._errors import MissingAdapterError # This import will be added

def test_get_raises_missingadaptererror_for_unknown_key():
    """
    Test that AdapterRegistry.get() raises MissingAdapterError for an unknown key.
    """
    registry = AdapterRegistry()
    with pytest.raises(MissingAdapterError) as excinfo:
        registry.get("bogus_key")
    # Assert that the correct exception type is raised
    assert excinfo.type is MissingAdapterError
    # Optionally, assert the content of the exception message
    assert "Adapter for key 'bogus_key' not found" in str(excinfo.value)
```

_Note: The specific path for `MissingAdapterError` will be confirmed when
creating the exception file._

#### 3.1.2 Test Case: get() - Known Key Returns Adapter

**Purpose:** To ensure that the change to `get()` does not break the existing
functionality of retrieving registered adapters.

**Setup:** Import necessary modules. Instantiate an `AdapterRegistry`. Register
a mock adapter with a known key.

**Test Implementation:**

```python
from unittest.mock import Mock
from lionagi._class_registry import AdapterRegistry
# from lionagi._errors import MissingAdapterError # Not needed for this specific test

def test_get_returns_registered_adapter():
    """
    Test that AdapterRegistry.get() returns the correct adapter for a known key.
    """
    registry = AdapterRegistry()
    mock_adapter = Mock()
    registry.register("test_adapter", mock_adapter)

    # Act
    retrieved_adapter = registry.get("test_adapter")

    # Assert
    assert retrieved_adapter is mock_adapter
```

### 3.2 Test Suite: Existing Call-Sites

No new tests are explicitly written for this. Existing unit and integration
tests that call `AdapterRegistry.get()` will be run to ensure they either handle
the new exception correctly or that the scenario they test does not involve an
unknown key lookup.

## 4. Integration Tests

Existing integration tests will be used to verify the correct
handling/propagation of `MissingAdapterError` at call-sites. No new integration
tests are added specifically for this issue.

## 5. API Tests

Not applicable for this issue.

## 6. Error Handling Tests

See Unit Test Case 3.1.1. This test specifically covers the new error handling
behavior.

## 7. Performance Tests

Not applicable for this issue.

## 8. Mock Implementation Details

A simple `unittest.mock.Mock` object is sufficient for testing the
`AdapterRegistry`'s behavior. No complex mock implementations are required.

## 9. Test Data

Simple string keys and mock adapter objects are sufficient for testing
`AdapterRegistry`.

```python
# Example Test Data
unknown_key = "bogus_key"
known_key = "test_adapter"
mock_adapter_instance = Mock()
```

## 10. Helper Functions

No new helper functions are required for these tests.

## 11. Test Coverage Targets

- **Line Coverage Target:** Ensure lines modified in `AdapterRegistry.get()` and
  the new exception class are covered.
- **Branch Coverage Target:** Ensure the new conditional logic (if any) in
  `get()` is covered.
- **Critical Modules:** `lionagi._class_registry.py` and `lionagi._errors.py`
  should maintain high coverage.

## 12. Continuous Integration

The standard CI workflow (`khive ci`) will be used to run these tests and verify
coverage targets before merging.

```yaml
# ... (standard CI workflow from IP)
name: Test
on: [push, pull_request]
jobs:
  tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install & Test
        run: |
          uv pip install -e .[dev] # Ensure test dependencies are installed
          pytest --cov=lionagi tests/ --cov-report=xml # Adjust cov report path if needed
      - name: Upload coverage
        uses: codecov/codecov-action@v3
```

_Note: The command `uv pip install -e .[dev]` is commonly used for installing
development dependencies, which include testing frameworks._

## 13. Notes and Caveats

### 13.1 Known Limitations

None currently identified for this specific change.

### 13.2 Future Improvements

None directly related to this exception handling change.
