prefer-table-driven-tests

Summary

Use table-driven tests to verify multiple test cases for a single function. Define a slice of structs containing inputs, expected outputs, and a test name, then iterate over them.

Rationale

• Compactness: Reduces boilerplate code by reusing the setup and assertion logic.
• Readability: Makes it easy to scan all test cases and see the variation in inputs/outputs.
• Extensibility: Adding a new test case is as simple as adding a new line to the slice.

Guidance

1. Anonymous Structs: Use an anonymous struct slice cases := []struct { ... } inside the test function.
2. Subtests: Use t.Run(tc.name, func(t *testing.T) { ... }) inside the loop to isolate failures.
3. Comprehensive Cases: Include edge cases, error cases, and happy paths in the table.

Examples