Tests: one snapshot helper (snapshot, snapshotAfter) replaces three copies

overlay_snapshot_test.go

@@ -1,56 +1,11 @@
 package mujica
 
 import (
-	"bytes"
-	"os"
-	"path/filepath"
-	"runtime"
-	"strings"
-	"testing"
 	"time"
 
 	"github.com/egoist/mygo/ui"
 )
 
-// overlaySnapshot is snapshot, with drive opening the real component through input before the capture.
-func overlaySnapshot(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)
-		tt.SetPreferences(ui.Preferences{ReduceMotion: true, TextScale: 1})
-		ready = true
-		tt.Frame()
-		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)
-		}
-	}
-}
-
 // overlayUntil draws frames until cond holds, for at most 5 s of wall time.
 func overlayUntil(tt *ui.Tester, cond func() bool) bool {
 	end := time.Now().Add(5 * time.Second)