add more case for filterProfile method

pkg/cover/client_test.go

@@ -36,7 +36,7 @@ func TestClientAction(t *testing.T) {
 	profileMockResponse := []byte("mode: count\nmockService/main.go:30.13,48.33 13 1\nb/b.go:30.13,48.33 13 1")
 	profileSuccessMockSvr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
-		w.Write(profileMockResponse)
+		_, _ = w.Write(profileMockResponse)
 	}))
 	defer profileSuccessMockSvr.Close()
 

pkg/cover/server_test.go

@@ -287,6 +287,16 @@ func TestFilterProfile(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:    "with invalid regular expression",
+			pattern: []string{"(?!a)"},
+			input: []*cover.Profile{
+				{
+					FileName: "some/fancy/gopath/a.go",
+				},
+			},
+			expectErr: true,
+		},
 	}
 
 	for _, tc := range tcs {