fix: an asleep browser Lane is not a stalled one on the admin page (#110)

Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

backend/web_test.go

@@ -776,6 +776,37 @@ func TestAdminPageShowsLaneStatus(t *testing.T) {
 	}
 }
 
+// A browser Lane under both wake thresholds holds Chrome asleep (ADR-0005), so
+// Series due with none checked is the design working, not a stopped Lane. The
+// two must not render the same mark: "not checking" is the owner's cue to go
+// looking, and spending it on the commonest healthy browser-Lane state trains
+// them to ignore it.
+func TestAsleepBrowserLaneIsNotMarkedStalled(t *testing.T) {
+	lanes := fakeLanes{latest.Status{
+		Lanes: []latest.LaneState{
+			{Site: "kagane", Due: 1, LastRun: time.Now(), Gap: 10 * time.Second, Browser: true, Asleep: true},
+		},
+		BrowserConfigured: true,
+		BrowserReachable:  true,
+	}}
+	router, st, _ := oauthWebTestServer(t, lanes)
+
+	req := httptest.NewRequest(http.MethodGet, "/ui/admin/lanes", nil)
+	req.AddCookie(sessionCookie(t, st))
+	rr := httptest.NewRecorder()
+	router.ServeHTTP(rr, req)
+	body := rr.Body.String()
+	if strings.Contains(body, "not checking") {
+		t.Errorf("an asleep browser Lane is marked as stalled:\n%s", body)
+	}
+	if !strings.Contains(body, "browser asleep") {
+		t.Errorf("an asleep browser Lane says nothing about why it read nothing:\n%s", body)
+	}
+	if strings.Contains(body, `class="attention"`) {
+		t.Errorf("an asleep browser Lane is coloured as unhealthy:\n%s", body)
+	}
+}
+
 // A Lane whose pass never reached a figure must not have that figure drawn as
 // a zero: a refusing Lane still reports the due count and gap its last real
 // pass saw, and a Lane that has never reached one omits it entirely.