selfupdate: report progress events; reports carry update stage, percent and log

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

selfupdate/selfupdate_test.go

@@ -152,3 +152,46 @@ func TestCheckReportsWithoutInstalling(t *testing.T) {
 		}
 	}
 }
+
+func TestReportsProgressThroughTheWholeUpdate(t *testing.T) {
+	cfg, _, _ := setup(t, fakeGitea(t, "v0.2.0", false, false), "v0.1.0")
+	var events []Event
+	cfg.Progress = func(e Event) { events = append(events, e) }
+	if _, err := CheckOnce(context.Background(), cfg); err != nil {
+		t.Fatal(err)
+	}
+	var stages []string
+	last, lines := 0, ""
+	for _, e := range events {
+		if len(stages) == 0 || stages[len(stages)-1] != e.Stage {
+			stages = append(stages, e.Stage)
+		}
+		if e.Pct >= 0 {
+			if e.Pct < last {
+				t.Errorf("progress went backwards: %d after %d (%+v)", e.Pct, last, e)
+			}
+			last = e.Pct
+		}
+		lines += e.Line + "\n"
+	}
+	if got := strings.Join(stages, ","); got != "checking,downloading,verifying,installing,restarting" {
+		t.Errorf("stages: %s", got)
+	}
+	if last != 100 || !strings.Contains(lines, "v0.2.0 is available") || !strings.Contains(lines, "checksum matches") {
+		t.Errorf("progress ended at %d with log:\n%s", last, lines)
+	}
+}
+
+func TestProgressReportsFailureAndNothingToDo(t *testing.T) {
+	cfg, _, _ := setup(t, fakeGitea(t, "v0.2.0", false, true), "v0.1.0")
+	var last Event
+	cfg.Progress = func(e Event) { last = e }
+	if _, err := CheckOnce(context.Background(), cfg); err == nil || last.Stage != "failed" || !strings.Contains(last.Line, "checksum") {
+		t.Errorf("err=%v last=%+v", err, last)
+	}
+	cfg, _, _ = setup(t, fakeGitea(t, "v0.2.0", false, false), "v0.2.0")
+	cfg.Progress = func(e Event) { last = e }
+	if tag, err := CheckOnce(context.Background(), cfg); err != nil || tag != "" || last.Stage != "done" || last.Pct != 100 {
+		t.Errorf("tag=%q err=%v last=%+v", tag, err, last)
+	}
+}