Go - code quality assurance - Automated Testing - testingパッケージ、T struct、Errorfメソッド、helper関数

Head First Go
楽天ブックス 紀伊國屋書店

開発環境

• macOS Mojave - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Go (プログラミング言語)

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

コード

larger_test.go

package compare

import (
 "fmt"
 "testing"
)

func TestFirstLarger(t *testing.T) {
 want := 2
 got := Larger(2, 1)
 if got != want {
  t.Errorf(errorString(2, 1, got, want))
 }
}

func TestSecondLarger(t *testing.T) {
 want := 8
 got := Larger(4, 8)
 if got != want {
  t.Errorf(errorString(4, 8, got, want))
 }
}

func errorString(a, b, got, want int) string {
 return fmt.Sprintf("Larger(%d, %d) = %d, want %d", a, b, got, want)
}

larger.go

package compare

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

入出力結果(Bash、cmd.exe(コマンドプロンプト)、Terminal)

$ go test
--- FAIL: TestFirstLarger (0.00s)
    larger_test.go:12: Larger(2, 1) = 1, want 2
--- FAIL: TestSecondLarger (0.00s)
    larger_test.go:20: Larger(4, 8) = 4, want 8
FAIL
exit status 1
FAIL headfirstgo/compare 0.005s
$