Fix s2geo documentation and code to reflect current plugin name

plugins/processors/s2geo/s2geo_test.go

@@ -0,0 +1,55 @@
+package geo
+
+import (
+	"testing"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGeo(t *testing.T) {
+	plugin := &Geo{
+		LatField:  "lat",
+		LonField:  "lon",
+		TagKey:    "s2_cell_id",
+		CellLevel: 11,
+	}
+
+	pluginMostlyDefault := &Geo{
+		CellLevel: 11,
+	}
+
+	err := plugin.Init()
+	require.NoError(t, err)
+
+	metric := testutil.MustMetric(
+		"mta",
+		map[string]string{},
+		map[string]interface{}{
+			"lat": 40.878738,
+			"lon": -72.517572,
+		},
+		time.Unix(1578603600, 0),
+	)
+
+	expected := []telegraf.Metric{
+		testutil.MustMetric(
+			"mta",
+			map[string]string{
+				"s2_cell_id": "89e8ed4",
+			},
+			map[string]interface{}{
+				"lat": 40.878738,
+				"lon": -72.517572,
+			},
+			time.Unix(1578603600, 0),
+		),
+	}
+
+	actual := plugin.Apply(metric)
+	testutil.RequireMetricsEqual(t, expected, actual)
+	actual = pluginMostlyDefault.Apply(metric)
+	testutil.RequireMetricsEqual(t, expected, actual)
+}