stuff

main_test.go

@@ -31,6 +31,23 @@ func TestHandleIndexRendersWatts(t *testing.T) {
 	}
 }
 
+func TestFormatGermanNumber(t *testing.T) {
+	tests := map[int]string{
+		0:       "0",
+		12:      "12",
+		999:     "999",
+		1000:    "1.000",
+		10000:   "10.000",
+		1234567: "1.234.567",
+		-1000:   "-1.000",
+	}
+	for input, want := range tests {
+		if got := formatGermanNumber(input); got != want {
+			t.Fatalf("formatGermanNumber(%d) = %q, want %q", input, got, want)
+		}
+	}
+}
+
 func TestHandleWriteRequiresSecret(t *testing.T) {
 	srv := &server{secret: "secret", store: &store{}}
 	req := httptest.NewRequest(http.MethodPost, "/write", bytes.NewBufferString(`{"watts":456}`))
@@ -116,7 +133,7 @@ func TestBuildHistoryChartRendersPolyline(t *testing.T) {
 func TestBuildHistoryChartUsesConfiguredMax(t *testing.T) {
 	history := []sample{{at: time.Date(2026, 4, 20, 12, 0, 0, 0, time.UTC), value: 250}}
 	chart := buildHistoryChart(history, 1000)
-	if !strings.Contains(string(chart), "1000 W") {
+	if !strings.Contains(string(chart), "1.000 W") {
 		t.Fatalf("chart did not include configured max: %s", string(chart))
 	}
 	if strings.Contains(string(chart), "250 W") {