writing-tests

The AAA pattern structures tests into three stages: Arrange (set up test data and mocks), Act (execute the code being tested), and Assert (verify the results). This pattern clarifies test intent and makes each test case independently readable and maintainable across React/TypeScript, Go, and Rust.

Yes, colocating tests with implementation in the same directory improves discoverability and maintenance. Language-specific naming patterns—such as `.test.ts` for React/TypeScript, `_test.go` for Go, and `#[cfg(test)]` modules for Rust—keep tests organized alongside their corresponding code.

Write test cases first using the AAA pattern, then implement React/TypeScript components to pass those tests. Use co-located test files with `.test.ts` naming, mock external dependencies, and test component behavior through unit and integration test workflows.

Structure backend tests with language-specific conventions: Go uses `_test.go` files with table-driven tests, while Rust uses `#[cfg(test)]` modules. Both enforce AAA pattern organization, co-location with source files, and separation of unit and integration test concerns.

Yes, mocking adapts to each language's testing framework. React/TypeScript uses Jest mocks, Go uses interfaces and test doubles, and Rust uses trait mocking. Each language applies consistent mocking workflow principles for isolating units under test and controlling external dependencies.

Apply the AAA pattern uniformly, maintain co-located test files with language-specific naming conventions, and follow reference guides for React/TypeScript, Go, and Rust. This standardized structure makes test organization predictable and coverage measurable across your entire codebase.