test(processors.filepath): Add unit-test for tracking metrics (#14776)

plugins/processors/filepath/filepath_test.go

@@ -3,10 +3,14 @@
 package filepath
 
 import (
+	"sync"
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/metric"
 	"github.com/influxdata/telegraf/testutil"
 )
 
@@ -68,3 +72,63 @@ func TestOptions_Apply(t *testing.T) {
 	}
 	runTestOptionsApply(t, tests)
 }
+
+func TestTracking(t *testing.T) {
+	inputRaw := []telegraf.Metric{
+		metric.New(
+			"test",
+			map[string]string{"sourcePath": samplePath},
+			map[string]interface{}{"sourcePath": samplePath},
+			time.Unix(0, 0),
+		),
+	}
+
+	expected := []telegraf.Metric{
+		metric.New(
+			"test",
+			map[string]string{"sourcePath": samplePath, "basePath": "file.log"},
+			map[string]interface{}{"sourcePath": samplePath, "basePath": "file.log"},
+			time.Unix(0, 0),
+		),
+	}
+
+	var mu sync.Mutex
+	delivered := make([]telegraf.DeliveryInfo, 0, len(inputRaw))
+	notify := func(di telegraf.DeliveryInfo) {
+		mu.Lock()
+		defer mu.Unlock()
+		delivered = append(delivered, di)
+	}
+
+	input := make([]telegraf.Metric, 0, len(inputRaw))
+	for _, m := range inputRaw {
+		tm, _ := metric.WithTracking(m, notify)
+		input = append(input, tm)
+	}
+
+	plugin := &Options{
+		BaseName: []BaseOpts{
+			{
+				Field: "sourcePath",
+				Tag:   "sourcePath",
+				Dest:  "basePath",
+			},
+		},
+	}
+
+	// Process expected metrics and compare with resulting metrics
+	actual := plugin.Apply(input...)
+	testutil.RequireMetricsEqual(t, expected, actual)
+
+	// Simulate output acknowledging delivery
+	for _, m := range actual {
+		m.Accept()
+	}
+
+	// Check delivery
+	require.Eventuallyf(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return len(expected) == len(delivered)
+	}, time.Second, 100*time.Millisecond, "%d delivered but %d expected", len(delivered), len(expected))
+}