package accumulate import ( "fmt" "strings" "testing" ) func echo(c string) string { return c } func capitalize(word string) string { return strings.Title(word) } var tests = []struct { expected []string given []string converter func(string) string description string }{ {[]string{}, []string{}, echo, "echo"}, {[]string{"echo", "echo", "echo", "echo"}, []string{"echo", "echo", "echo", "echo"}, echo, "echo"}, {[]string{"First", "Letter", "Only"}, []string{"first", "letter", "only"}, capitalize, "capitalize"}, {[]string{"HELLO", "WORLD"}, []string{"hello", "world"}, strings.ToUpper, "strings.ToUpper"}, } func TestAccumulate(t *testing.T) { for _, test := range tests { actual := Accumulate(test.given, test.converter) if fmt.Sprintf("%q", actual) != fmt.Sprintf("%q", test.expected) { t.Fatalf("Accumulate(%q, %q): expected %q, actual %q", test.given, test.description, test.expected, actual) } } } func BenchmarkAccumulate(b *testing.B) { for i := 0; i < b.N; i++ { for _, test := range tests { Accumulate(test.given, test.converter) } } }