Tariff: base cache validity on update interval instead of rate coverage (#32168)

tariff/proxy_cache_test.go

@@ -0,0 +1,29 @@
+package tariff
+
+import (
+	"testing"
+	"time"
+
+	"github.com/evcc-io/evcc/api"
+	"github.com/evcc-io/evcc/server/db"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCacheInterval(t *testing.T) {
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+
+	p := &cachingProxy{key: "test", interval: time.Hour}
+	require.NoError(t, p.cachePut(api.TariffTypeSolar, api.Rates{
+		{Start: time.Now(), End: time.Now().Add(time.Hour), Value: 1},
+	}))
+
+	// within interval
+	res, err := p.cacheGet()
+	require.NoError(t, err)
+	require.Equal(t, api.TariffTypeSolar, res.Type)
+
+	// interval elapsed
+	p.cached.Updated = time.Now().Add(-2 * time.Hour)
+	_, err = p.cacheGet()
+	require.Error(t, err)
+}