Add US unit support for weather observations and forecasts

internal/core/payload_test.go

@@ -0,0 +1,119 @@
+package core
+
+import (
+	"math"
+	"testing"
+	"time"
+
+	"gitea.maximumdirect.net/ejr/weatherfeeder/model"
+)
+
+func TestObservationPayloadUS(t *testing.T) {
+	obs := &model.WeatherObservation{
+		StationID:               "KSTL",
+		Timestamp:               time.Date(2026, 3, 20, 0, 0, 0, 0, time.UTC),
+		ConditionCode:           2,
+		TemperatureC:            float64Ptr(20),
+		DewpointC:               float64Ptr(10),
+		WindSpeedKmh:            float64Ptr(100),
+		WindGustKmh:             float64Ptr(80),
+		BarometricPressurePa:    float64Ptr(101325),
+		VisibilityMeters:        float64Ptr(1609.344),
+		ApparentTemperatureC:    float64Ptr(25),
+		RelativeHumidityPercent: float64Ptr(50),
+	}
+
+	payload := ObservationPayload(obs, UnitsUS)
+	converted, ok := payload.(WeatherObservationUS)
+	if !ok {
+		t.Fatalf("expected WeatherObservationUS payload, got %T", payload)
+	}
+
+	assertApprox(t, converted.TemperatureF, 68.0, 0.0001)
+	assertApprox(t, converted.WindSpeedMph, 62.1371192237, 0.0001)
+	assertApprox(t, converted.BarometricPressureInHg, 29.9212524019, 0.0001)
+	assertApprox(t, converted.VisibilityMiles, 1.0, 0.0001)
+
+	if converted.TemperatureF == nil || converted.DewpointF == nil || converted.ApparentTemperatureF == nil {
+		t.Fatalf("expected converted Fahrenheit fields to be populated")
+	}
+}
+
+func TestForecastPayloadUS(t *testing.T) {
+	issuedAt := time.Date(2026, 3, 20, 12, 0, 0, 0, time.UTC)
+	updatedAt := issuedAt.Add(1 * time.Hour)
+	run := &model.WeatherForecastRun{
+		LocationID:      "stl",
+		IssuedAt:        issuedAt,
+		UpdatedAt:       &updatedAt,
+		Product:         model.ForecastProductHourly,
+		ElevationMeters: float64Ptr(1000),
+		Periods: []model.WeatherForecastPeriod{
+			{
+				StartTime:             issuedAt,
+				EndTime:               issuedAt.Add(1 * time.Hour),
+				ConditionCode:         63,
+				TemperatureC:          float64Ptr(0),
+				TemperatureCMin:       float64Ptr(-5),
+				TemperatureCMax:       float64Ptr(5),
+				WindSpeedKmh:          float64Ptr(64.37376),
+				PrecipitationAmountMm: float64Ptr(25.4),
+				SnowfallDepthMM:       float64Ptr(50.8),
+			},
+		},
+	}
+
+	payload := ForecastPayload(run, UnitsUS)
+	converted, ok := payload.(WeatherForecastRunUS)
+	if !ok {
+		t.Fatalf("expected WeatherForecastRunUS payload, got %T", payload)
+	}
+
+	assertApprox(t, converted.ElevationFeet, 3280.839895, 0.0001)
+	if len(converted.Periods) != 1 {
+		t.Fatalf("expected 1 period, got %d", len(converted.Periods))
+	}
+	period := converted.Periods[0]
+	assertApprox(t, period.TemperatureF, 32.0, 0.0001)
+	assertApprox(t, period.TemperatureFMin, 23.0, 0.0001)
+	assertApprox(t, period.TemperatureFMax, 41.0, 0.0001)
+	assertApprox(t, period.WindSpeedMph, 40.0, 0.0001)
+	assertApprox(t, period.PrecipitationAmountIn, 1.0, 0.0001)
+	assertApprox(t, period.SnowfallDepthIn, 2.0, 0.0001)
+}
+
+func TestMetricPassthroughAndNilHandling(t *testing.T) {
+	obs := &model.WeatherObservation{}
+	metric := ObservationPayload(obs, UnitsMetric)
+	metricObs, ok := metric.(*model.WeatherObservation)
+	if !ok {
+		t.Fatalf("expected metric payload to remain model type, got %T", metric)
+	}
+	if metricObs != obs {
+		t.Fatalf("expected metric payload to be original pointer")
+	}
+
+	if ObservationPayload(nil, UnitsUS) != nil {
+		t.Fatalf("expected nil observation input to return nil payload")
+	}
+	if ForecastPayload(nil, UnitsUS) != nil {
+		t.Fatalf("expected nil forecast input to return nil payload")
+	}
+	if AlertsPayload(nil, UnitsUS) != nil {
+		t.Fatalf("expected nil alerts input to return nil payload")
+	}
+}
+
+func float64Ptr(v float64) *float64 {
+	return &v
+}
+
+func assertApprox(t *testing.T, got *float64, want, eps float64) {
+	t.Helper()
+	if got == nil {
+		t.Fatalf("expected value near %f, got nil", want)
+	}
+	if math.Abs(*got-want) > eps {
+		t.Fatalf("expected %f +/- %f, got %f", want, eps, *got)
+	}
+}