Regression testing for agent changes in Agentic AI

Introduction

Regression testing helps make sure that when you change an AI agent, it still works well and does not break old features.

After updating the AI agent's code or logic

When adding new skills or tasks to the agent

Before releasing a new version of the agent

To check if bug fixes did not cause new problems

When changing the environment or data the agent uses

Syntax

Agentic AI

def regression_test(agent, test_cases):
    results = {}
    for name, input_data, expected_output in test_cases:
        output = agent.run(input_data)
        results[name] = (output == expected_output)
    return results

This function runs a list of test cases on the agent and checks if outputs match expected results.

Each test case has a name, input, and expected output to compare.

Examples

This example tests if the agent responds correctly to greetings and farewells.

Agentic AI

test_cases = [
    ('greet_test', 'Hello', 'Hi! How can I help?'),
    ('farewell_test', 'Bye', 'Goodbye!')
]
results = regression_test(agent, test_cases)

Here, the agent is tested on math and weather questions to check consistency.

Agentic AI

test_cases = [
    ('math_test', '2 + 2', '4'),
    ('weather_test', 'Weather today?', 'Sunny')
]
results = regression_test(agent, test_cases)

Sample Model

This program defines a simple agent and runs regression tests to check if it responds correctly to different inputs.

Agentic AI

class SimpleAgent:
    def run(self, input_text):
        if input_text == 'Hello':
            return 'Hi! How can I help?'
        elif input_text == 'Bye':
            return 'Goodbye!'
        else:
            return 'I do not understand.'

def regression_test(agent, test_cases):
    results = {}
    for name, input_data, expected_output in test_cases:
        output = agent.run(input_data)
        results[name] = (output == expected_output)
    return results

agent = SimpleAgent()
test_cases = [
    ('greet_test', 'Hello', 'Hi! How can I help?'),
    ('farewell_test', 'Bye', 'Goodbye!'),
    ('unknown_test', 'What?', 'I do not understand.')
]
results = regression_test(agent, test_cases)
print(results)

Important Notes

Always keep your test cases updated when you add new features.

Regression tests help catch bugs early before users see them.

Automate regression testing to save time and avoid mistakes.

Summary

Regression testing checks if agent changes break old behavior.

Use test cases with inputs and expected outputs to verify the agent.

Run regression tests regularly to keep your agent reliable.