How to Write Table-Driven Tests Idiomatically in Go

Testing
2026-04-17T12:05:42+00:00
Write Go table-driven tests by defining a slice of test cases with inputs and expected outputs, then looping over them in a test function to verify behavior.

Write a table-driven test by defining a slice of structs containing inputs and expected outputs, then loop over that slice in your test function to verify behavior for each case.

func TestMyFunction(t *testing.T) {
	tests := []struct {
		name     string
		input    int
		expected int
	}{
		{"positive", 1, 2},
		{"negative", -1, 0},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := MyFunction(tt.input); got != tt.expected {
				t.Errorf("MyFunction(%v) = %v, want %v", tt.input, got, tt.expected)
			}
		})
	}
}

This pattern keeps test logic DRY, makes adding new cases trivial, and provides clear failure messages via t.Run subtests.