Improve test coverage

xonvanetta · Mar 20, 2023 · fe2ec07 · fe2ec07
1 parent 6327e1c
commit fe2ec07
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Showing 5 changed files with 176 additions and 17 deletions.
diff --git a/collectors/collector_manager_test.go b/collectors/collector_manager_test.go
@@ -7,6 +7,15 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+func TestNewCollectorManager(t *testing.T) {
+	mockEndpoint := "http://localhost:9600"
+	cm := NewCollectorManager(mockEndpoint)
+
+	if cm == nil {
+		t.Error("Expected collector manager to be initialized")
+	}
+}
+
 type mockCollector struct{}
 
 func (m *mockCollector) Collect(ctx context.Context, ch chan<- prometheus.Metric) error {

diff --git a/config/env_helper_test.go b/config/env_helper_test.go
@@ -24,3 +24,12 @@ func TestGetEnvWithDefault(t *testing.T) {
 		}
 	})
 }
+
+func TestInitializeEnv(t *testing.T) {
+	t.Run("should throw an error if .env file is not found", func(t *testing.T) {
+		err := InitializeEnv()
+		if err == nil {
+			t.Errorf("expected error but got nil")
+		}
+	})
+}
diff --git a/fetcher/logstash_client/client_test.go b/fetcher/logstash_client/client_test.go
@@ -1,9 +1,19 @@
 package logstash_client
 
 import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
 	"testing"
+	"time"
 )
 
+type TestResponse struct {
+	Foo string `json:"foo"`
+}
+
 func TestNewClient(t *testing.T) {
 	t.Run("should return a new client for the default endpoint", func(t *testing.T) {
 		client := NewClient("")
@@ -22,3 +32,110 @@ func TestNewClient(t *testing.T) {
 		}
 	})
 }
+
+func TestGetMetrics(t *testing.T) {
+	t.Run("should return a valid response", func(t *testing.T) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"foo": "bar"}`))
+		}))
+		defer server.Close()
+
+		httpClient := &http.Client{}
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+
+		result, err := getMetrics[TestResponse](ctx, httpClient, server.URL)
+		if err != nil {
+			t.Errorf("expected no error, got %s", err)
+		}
+
+		if result.Foo != "bar" {
+			t.Errorf("expected foo to be bar, got %s", result.Foo)
+		}
+	})
+
+	t.Run("should return an error if the response is invalid", func(t *testing.T) {
+		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"foo": "bar"`))
+		}))
+		defer server.Close()
+
+		httpClient := &http.Client{}
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+
+		result, err := getMetrics[TestResponse](ctx, httpClient, server.URL)
+		if err == nil {
+			t.Errorf("expected error, got nil")
+		}
+
+		if result != nil {
+			t.Errorf("expected result to be nil, got %v", result)
+		}
+	})
+
+	t.Run("should return an error if the request fails", func(t *testing.T) {
+		httpClient := &http.Client{}
+		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+
+		result, err := getMetrics[TestResponse](ctx, httpClient, "http://localhost:96010")
+		if err == nil {
+			t.Errorf("expected error, got nil")
+		}
+
+		if result != nil {
+			t.Errorf("expected result to be nil, got %v", result)
+		}
+	})
+
+	t.Run("should return an error if the context is cancelled", func(t *testing.T) {
+		httpClient := &http.Client{}
+		ctx, cancel := context.WithCancel(context.Background())
+		cancel()
+
+		result, err := getMetrics[TestResponse](ctx, httpClient, "http://localhost:96010")
+		if err == nil {
+			t.Errorf("expected error, got nil")
+		}
+
+		if result != nil {
+			t.Errorf("expected result to be nil, got %v", result)
+		}
+	})
+}
+
+func TestDeserializeHttpResponse(t *testing.T) {
+
+	t.Run("should properly deserialize a valid response", func(t *testing.T) {
+		httpResponseMock := &http.Response{
+			Body: io.NopCloser(strings.NewReader(`{"foo": "bar"}`)),
+		}
+
+		result, err := deserializeHttpResponse[TestResponse](httpResponseMock)
+		if err != nil {
+			t.Errorf("expected no error, got %s", err)
+		}
+
+		if result.Foo != "bar" {
+			t.Errorf("expected foo to be bar, got %s", result.Foo)
+		}
+	})
+
+	t.Run("should return an error if the response is invalid", func(t *testing.T) {
+		httpResponseMock := &http.Response{
+			Body: io.NopCloser(strings.NewReader(`{"foo": "bar"`)),
+		}
+
+		result, err := deserializeHttpResponse[TestResponse](httpResponseMock)
+		if err == nil {
+			t.Errorf("expected error, got nil")
+		}
+
+		if result != nil {
+			t.Errorf("expected result to be nil, got %v", result)
+		}
+	})
+}
diff --git a/prometheus_helper/prometheus_helper_test.go b/prometheus_helper/prometheus_helper_test.go
@@ -31,27 +31,36 @@ func TestSimpleDescHelper(t *testing.T) {
 }
 
 func TestExtractFqdnName(t *testing.T) {
-	helper := &SimpleDescHelper{
-		Namespace: "logstash_exporter",
-		Subsystem: "test",
-	}
+	t.Run("should properly extract fqdn from valid metric description", func(t *testing.T) {
+		helper := &SimpleDescHelper{
+			Namespace: "logstash_exporter",
+			Subsystem: "test",
+		}
 
-	metricSubname := "fqdn_metric"
+		metricSubname := "fqdn_metric"
 
-	descriptors := []*prometheus.Desc{
-		helper.NewDesc(metricSubname),
-		helper.NewDescWithHelp(metricSubname, "help"),
-		helper.NewDescWithHelpAndLabel(metricSubname, "help", "label"),
-	}
+		descriptors := []*prometheus.Desc{
+			helper.NewDesc(metricSubname),
+			helper.NewDescWithHelp(metricSubname, "help"),
+			helper.NewDescWithHelpAndLabel(metricSubname, "help", "label"),
+		}
+
+		for _, desc := range descriptors {
+			fqdn, err := ExtractFqName(desc.String())
+			if err != nil {
+				t.Errorf("failed to extract fqName from metric %s", desc)
+			}
 
-	for _, desc := range descriptors {
-		fqdn, err := ExtractFqName(desc.String())
-		if err != nil {
-			t.Errorf("failed to extract fqName from metric %s", desc)
+			if fqdn != fmt.Sprintf("logstash_exporter_test_%s", metricSubname) {
+				t.Errorf("incorrect fqdn, expected %s but got %s", "logstash_exporter_test_"+metricSubname, fqdn)
+			}
 		}
+	})
 
-		if fqdn != fmt.Sprintf("logstash_exporter_test_%s", metricSubname) {
-			t.Errorf("incorrect fqdn, expected %s but got %s", "logstash_exporter_test_"+metricSubname, fqdn)
+	t.Run("should return error if metric description is invalid", func(t *testing.T) {
+		_, err := ExtractFqName("invalid metric description")
+		if err == nil {
+			t.Errorf("expected error but got nil")
 		}
-	}
+	})
 }
diff --git a/server/healthcheck_test.go b/server/healthcheck_test.go
@@ -38,4 +38,19 @@ func TestHealthCheck(t *testing.T) {
 	t.Run("404 status", func(t *testing.T) {
 		runTest(http.StatusNotFound, http.StatusInternalServerError)
 	})
+
+	t.Run("no response", func(t *testing.T) {
+		handler := getHealthCheck("http://localhost:12345")
+		req, err := http.NewRequest(http.MethodGet, "/", nil)
+		if err != nil {
+			t.Fatalf("Error creating request: %v", err)
+		}
+		rr := httptest.NewRecorder()
+
+		handler(rr, req)
+
+		if status := rr.Code; status != http.StatusInternalServerError {
+			t.Errorf("Handler returned wrong status code: got %v want %v", status, http.StatusInternalServerError)
+		}
+	})
 }