Add unit tests for NATS JetStream scaler (#3521)

Signed-off-by: Deepak <[email protected]>

pkg/scalers/nats_jetstream_scaler_test.go

@@ -0,0 +1,77 @@
+package scalers
+
+import (
+	"context"
+	"net/http"
+	"testing"
+)
+
+type parseNATSJetStreamMetadataTestData struct {
+	metadata   map[string]string
+	authParams map[string]string
+	isError    bool
+}
+
+type natsJetStreamMetricIdentifier struct {
+	metadataTestData *parseNATSJetStreamMetadataTestData
+	scalerIndex      int
+	name             string
+}
+
+var testNATSJetStreamMetadata = []parseNATSJetStreamMetadataTestData{
+	// nothing passed
+	{map[string]string{}, map[string]string{}, true},
+	// Missing account name, should fail
+	{map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222", "stream": "mystream", "consumer": "pull_consumer"}, map[string]string{}, true},
+	// Missing stream name, should fail
+	{map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222", "account": "$G", "consumer": "pull_consumer"}, map[string]string{}, true},
+	// Missing consumer name should fail
+	{map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222", "account": "$G", "stream": "mystream"}, map[string]string{}, true},
+	// Missing nats server monitoring endpoint, should fail
+	{map[string]string{"account": "$G", "stream": "mystream"}, map[string]string{}, true},
+	// All good.
+	{map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222", "account": "$G", "stream": "mystream", "consumer": "pull_consumer"}, map[string]string{}, false},
+	// All good + activationLagThreshold
+	{map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222", "account": "$G", "stream": "mystream", "consumer": "pull_consumer", "activationLagThreshold": "10"}, map[string]string{}, false},
+	// natsServerMonitoringEndpoint is defined in authParams
+	{map[string]string{"account": "$G", "stream": "mystream", "consumer": "pull_consumer"}, map[string]string{"natsServerMonitoringEndpoint": "nats.nats:8222"}, false},
+	// Missing nats server monitoring endpoint , should fail
+	{map[string]string{"account": "$G", "stream": "mystream", "consumer": "pull_consumer"}, map[string]string{"natsServerMonitoringEndpoint": ""}, true},
+}
+
+var natsJetStreamMetricIdentifiers = []natsJetStreamMetricIdentifier{
+	{&testNATSJetStreamMetadata[5], 0, "s0-nats-jetstream-mystream"},
+	{&testNATSJetStreamMetadata[5], 1, "s1-nats-jetstream-mystream"},
+}
+
+func TestNATSJetStreamParseMetadata(t *testing.T) {
+	for _, testData := range testNATSJetStreamMetadata {
+		_, err := parseNATSJetStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadata, AuthParams: testData.authParams})
+		if err != nil && !testData.isError {
+			t.Error("Expected success but got error", err)
+		} else if testData.isError && err == nil {
+			t.Error("Expected error but got success")
+		}
+	}
+}
+
+func TestNATSJetStreamGetMetricSpecForScaling(t *testing.T) {
+	for _, testData := range natsJetStreamMetricIdentifiers {
+		ctx := context.Background()
+		meta, err := parseNATSJetStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ScalerIndex: testData.scalerIndex})
+		if err != nil {
+			t.Fatal("Could not parse metadata:", err)
+		}
+		mockStanScaler := natsJetStreamScaler{
+			stream:     nil,
+			metadata:   meta,
+			httpClient: http.DefaultClient,
+		}
+
+		metricSpec := mockStanScaler.GetMetricSpecForScaling(ctx)
+		metricName := metricSpec[0].External.Metric.Name
+		if metricName != testData.name {
+			t.Error("Wrong External metric source name:", metricName)
+		}
+	}
+}