Go - code quality assurance - Automated Testing - fmt, Sprintf

開発環境

Head First Go、 Jay McGavren(著)、O’Reilly Media)の Chapter 14(code quality assurance - Automated Testing)、p.416(Code Magnets)の解答を求めてみる。

コード

compare/larger.go

package compare

func Larger(a int, b int) int {
	if a < b {
		return a
	}
	return b
}

コード

campare/larger_test.go

package compare

import (
	"fmt"
	"testing"
)

func TestFirstLarger(t *testing.T) {
	want := 2
	got := Larger(2, 1)
	if got != want {
		t.Error(errorString(2, 1, got, want))
	}
}
func TestSecondLarger(t *testing.T) {
	want := 8
	got := Larger(4, 8)
	if got != want {
		t.Error(errorString(4, 3, got, want))
	}
}
func errorString(a int, b int, got int, want int) string {
	return fmt.Sprintf("Larger(%d, %d) = %d, want %d", a, b, got, want)
}

入出力結果(Terminal, Zsh)

% go test
--- FAIL: TestFirstLarger (0.00s)
    larger_test.go:12: Larger(2, 1) = 1, want 2
--- FAIL: TestSecondLarger (0.00s)
    larger_test.go:19: Larger(4, 3) = 4, want 8
FAIL
exit status 1
FAIL	compare	0.282s
% cat go.md
cat: go.md: No such file or directory
% cat go.mod
module compare

go 1.23.4
%