What methods and approaches do you use to verify the functionality of your code?

To check the functionality of code in Go, I use several approaches:

• Unit testing with the testing package. I write tests for functions and methods, checking different cases.
• Logging and debugging — I add log outputs using log or fmt to track the state.
• Profiling and performance analysis — using pprof to identify bottlenecks.
• Integration tests — I verify the interaction of multiple components.
• Using static analysis — go vet, golint to find potential errors.

Example of a simple test:

func TestSum(t *testing.T) {
    got := Sum(2, 3)
    want := 5
    if got != want {
        t.Errorf("Sum(2, 3) = %d; want %d", got, want)
    }
}