Files
MujicaUI/snapshot_test.go
T

75 lines
1.8 KiB
Go

package mujica
import (
"bytes"
"flag"
"image"
"image/png"
"os"
"path/filepath"
"runtime"
"strings"
"testing"
"github.com/egoist/mygo/ui"
)
var update = flag.Bool("update", false, "rewrite snapshots")
// snapshot compares view in both themes with testdata/snapshots/<os>/<name>-<mode>.png.
func snapshot(t *testing.T, name string, w, h int, view func(c *ui.Context)) {
t.Helper()
snapshotAfter(t, name, w, h, view, nil)
}
// snapshotAfter is snapshot with drive sending input before the capture.
func snapshotAfter(t *testing.T, name string, w, h int, view func(c *ui.Context), drive func(tt *ui.Tester)) {
t.Helper()
for _, m := range []Mode{Light, Dark} {
ready := false
tt := ui.NewTester(func(c *ui.Context) {
Use(c, Settings{Mode: m})
if ready {
view(c)
}
}, w, h)
// Animations must not paint before ReduceMotion applies.
tt.SetPreferences(ui.Preferences{ReduceMotion: true, TextScale: 1})
ready = true
tt.Frame()
if drive != nil {
drive(tt)
}
got := encode(t, tt.Image())
path := filepath.Join("testdata", "snapshots", runtime.GOOS, name+"-"+strings.ToLower(m.String())+".png")
if *update {
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
t.Fatal(err)
}
if err := os.WriteFile(path, got, 0o644); err != nil {
t.Fatal(err)
}
continue
}
want, err := os.ReadFile(path)
if err != nil {
t.Fatalf("%v (run go test -update)", err)
}
if !bytes.Equal(got, want) {
if err := os.WriteFile(path+".got.png", got, 0o644); err != nil {
t.Fatal(err)
}
t.Errorf("%s differs; see %s.got.png", path, path)
}
}
}
func encode(t *testing.T, img image.Image) []byte {
t.Helper()
var b bytes.Buffer
if err := png.Encode(&b, img); err != nil {
t.Fatal(err)
}
return b.Bytes()
}