feat(pprof): add pprof HTTP server (#807)

- `PPROF_ENABLED=no`
- `PPROF_BLOCK_PROFILE_RATE=0`
- `PPROF_MUTEX_PROFILE_RATE=0`
- `PPROF_HTTP_SERVER_ADDRESS=":6060"`

internal/httpserver/server_test.go

@@ -0,0 +1,67 @@
+package httpserver
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+//go:generate mockgen -destination=logger_mock_test.go -package $GOPACKAGE . Logger
+
+func Test_New(t *testing.T) {
+	t.Parallel()
+
+	someHandler := http.NewServeMux()
+	someLogger := &testLogger{}
+
+	testCases := map[string]struct {
+		settings   Settings
+		expected   *Server
+		errWrapped error
+		errMessage string
+	}{
+		"empty settings": {
+			errWrapped: ErrHandlerIsNotSet,
+			errMessage: "http server settings validation failed: HTTP handler cannot be left unset",
+		},
+		"filled settings": {
+			settings: Settings{
+				Name:            stringPtr("name"),
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
+			},
+			expected: &Server{
+				name:            "name",
+				address:         ":8001",
+				handler:         someHandler,
+				logger:          someLogger,
+				shutdownTimeout: time.Second,
+			},
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			server, err := New(testCase.settings)
+			assert.ErrorIs(t, err, testCase.errWrapped)
+			if testCase.errWrapped != nil {
+				require.EqualError(t, err, testCase.errMessage)
+			}
+
+			if server != nil {
+				assert.NotNil(t, server.addressSet)
+				server.addressSet = nil
+			}
+
+			assert.Equal(t, testCase.expected, server)
+		})
+	}
+}