adds tests

Signed-off-by: mattb18 <[email protected]>

prober/grpc_test.go

@@ -414,3 +414,34 @@ func TestGRPCHealthCheckUnimplemented(t *testing.T) {
 
 	checkRegistryResults(expectedResults, mfs, t)
 }
+
+func TestGRPCAbsentFailedTLS(t *testing.T) {
+	testCTX, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	registry := prometheus.NewRegistry()
+
+	// probe and invalid port to trigger TCP/TLS error
+	result := ProbeGRPC(testCTX, "localhost:0",
+		config.Module{Timeout: time.Second, GRPC: config.GRPCProbe{
+			IPProtocolFallback: false,
+			Service:            "NonExistingService",
+		},
+		}, registry, promslog.NewNopLogger())
+
+	if result {
+		t.Fatalf("GRPC probe succeeded, should have failed")
+	}
+
+	mfs, err := registry.Gather()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	absentMetrics := []string{
+		"probe_ssl_earliest_cert_expiry",
+		"probe_tls_version_info",
+		"probe_ssl_last_chain_info",
+	}
+
+	checkAbsentMetrics(absentMetrics, mfs, t)
+}

prober/utils_test.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"math/big"
 	"net"
+	"slices"
 	"testing"
 	"time"
 
@@ -249,3 +250,12 @@ func checkMetrics(expected map[string]map[string]map[string]struct{}, mfs []*dto
 		}
 	}
 }
+
+func checkAbsentMetrics(absent []string, mfs []*dto.MetricFamily, t *testing.T) {
+	for _, v := range mfs {
+		name := v.GetName()
+		if slices.Contains(absent, name) {
+			t.Fatalf("metric %s was found but should be absent", name)
+		}
+	}
+}