test(plugin): improve test coverage for pprof (#7473)

Add tests for Startup/Shutdown methods and HTTP endpoints.
Enhance setup tests with edge cases. Increases test coverage
from 58% to 100%.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

plugin/pprof/pprof_test.go

@@ -0,0 +1,163 @@
+package pprof
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestHandlerStartup(t *testing.T) {
+	h := &handler{
+		addr:     ":0", // Use available port
+		rateBloc: 5,
+	}
+
+	err := h.Startup()
+	if err != nil {
+		t.Fatalf("Expected no error, got: %v", err)
+	}
+	defer h.Shutdown()
+
+	if h.ln == nil {
+		t.Fatal("Expected listener to be set")
+	}
+
+	if h.mux == nil {
+		t.Fatal("Expected mux to be set")
+	}
+
+	// Verify the server is actually listening
+	addr := h.ln.Addr().String()
+	if addr == "" {
+		t.Fatal("Expected non-empty address")
+	}
+}
+
+func TestHandlerShutdown(t *testing.T) {
+	h := &handler{
+		addr:     ":0",
+		rateBloc: 1,
+	}
+
+	// Start the handler
+	err := h.Startup()
+	if err != nil {
+		t.Fatalf("Expected no error during startup, got: %v", err)
+	}
+
+	// Verify listener exists
+	if h.ln == nil {
+		t.Fatal("Expected listener to be set after startup")
+	}
+
+	// Shutdown and verify no error
+	err = h.Shutdown()
+	if err != nil {
+		t.Errorf("Expected no error during shutdown, got: %v", err)
+	}
+}
+
+func TestHandlerShutdownWithoutStartup(t *testing.T) {
+	h := &handler{}
+
+	// Shutdown without startup should not error
+	err := h.Shutdown()
+	if err != nil {
+		t.Errorf("Expected no error when shutting down without startup, got: %v", err)
+	}
+}
+
+func TestHandlerPprofEndpoints(t *testing.T) {
+	h := &handler{
+		addr:     ":0",
+		rateBloc: 1,
+	}
+
+	err := h.Startup()
+	if err != nil {
+		t.Fatalf("Expected no error during startup, got: %v", err)
+	}
+	defer h.Shutdown()
+
+	// Wait a bit for the server to fully start
+	time.Sleep(100 * time.Millisecond)
+
+	baseURL := fmt.Sprintf("http://%s", h.ln.Addr().String())
+
+	testCases := []struct {
+		path           string
+		expectedStatus int
+	}{
+		{"/debug/pprof/", http.StatusOK},        // Index page
+		{"/debug/pprof/cmdline", http.StatusOK}, // Cmdline
+		{"/debug/pprof/symbol", http.StatusOK},  // Symbol
+	}
+
+	for _, tc := range testCases {
+		url := baseURL + tc.path
+		resp, err := http.Get(url)
+		if err != nil {
+			t.Errorf("Error making request to %s: %v", url, err)
+			continue
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode != tc.expectedStatus {
+			t.Errorf("Expected status %d for %s, got %d", tc.expectedStatus, tc.path, resp.StatusCode)
+		}
+	}
+}
+
+func TestHandlerPprofRedirect(t *testing.T) {
+	h := &handler{
+		addr:     ":0",
+		rateBloc: 1,
+	}
+
+	err := h.Startup()
+	if err != nil {
+		t.Fatalf("Expected no error during startup, got: %v", err)
+	}
+	defer h.Shutdown()
+
+	// Wait a bit for the server to fully start
+	time.Sleep(100 * time.Millisecond)
+
+	// Create a client that doesn't follow redirects
+	client := &http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
+
+	url := fmt.Sprintf("http://%s/debug/pprof", h.ln.Addr().String())
+	resp, err := client.Get(url)
+	if err != nil {
+		t.Fatalf("Error making request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusFound {
+		t.Errorf("Expected status %d, got %d", http.StatusFound, resp.StatusCode)
+	}
+
+	location := resp.Header.Get("Location")
+	if !strings.HasSuffix(location, "/debug/pprof/") {
+		t.Errorf("Expected redirect to end with '/debug/pprof/', got: %s", location)
+	}
+}
+
+func TestHandlerStartupInvalidAddress(t *testing.T) {
+	h := &handler{
+		addr:     "invalid-address-format",
+		rateBloc: 1,
+	}
+
+	err := h.Startup()
+	if err == nil {
+		t.Fatal("Expected error for invalid address format")
+		defer h.Shutdown()
+	}
+}

plugin/pprof/setup_test.go

@@ -29,6 +29,12 @@ func TestPProf(t *testing.T) {
 		{`pprof {
                    block 20 30
                 }`, true},
+		{`pprof {
+                   block invalid
+                }`, true},
+		{`pprof {
+                   unknown_property
+                }`, true},
 		{`pprof
           pprof`, true},
 	}