Comprehensive unit testing

Prioritize unit tests over integration tests. Test state transitions, edge cases, serialization round-trips. Every implementation MUST include a corresponding test file. UI tests are fragile — prefer testing component logic as unit tests.

Testing

Every change MUST have tests. Every bug fix MUST have a regression test. Unit tests SHOULD be prioritized over integration tests. Test state transitions, edge cases, and serialization round-trips. UI tests are fragile — prefer testing component logic as unit tests.

TypeScript

Use Playwright for end-to-end and visual regression testing. Screenshot comparison for snapshot tests. Use Storybook for component catalog and visual tests where applicable.

C#

1. xUnit with [Fact] for single tests and [Theory]/[InlineData] for parameterized tests.
2. FluentAssertions for readable assertions.
3. NSubstitute for mocking.
4. Every change needs tests. Every bug fix needs a regression test.
5. Prioritize unit tests over integration tests.

[Fact]
public void ParseOrder_WithValidInput_ReturnsOrder()
{
    var result = OrderParser.Parse(validJson);
    result.Should().NotBeNull();
    result.OrderId.Should().Be("ORD-123");
}

[Theory]
[InlineData("", false)]
[InlineData("valid@email.com", true)]
[InlineData("no-at-sign", false)]
public void IsValidEmail_ReturnsExpected(string input, bool expected)
{
    EmailValidator.IsValid(input).Should().Be(expected);
}

Python

1. Use pytest for all tests.
2. Every change needs tests. Every bug fix needs a regression test.
3. Prioritize unit tests over integration tests.
4. Production dashboard data MUST NOT be removed or modified during testing — use demo port 9888, not production port 8888.

Change History