use EXPECT_PRED2

test/c/ctest_util_backtrace.cpp

@@ -3,11 +3,12 @@
 
 #include <util_backtrace.h>
 
-class UtilBacktraceCTest : public ::testing::Test {};
-
-bool ContainsSubstring(const std::string &str, const std::string &substr) {
-    return str.find(substr) != std::string::npos;
-}
+class UtilBacktraceCTest : public ::testing::Test {
+    protected:
+    static bool ContainsSubstring(const std::string &str, const std::string &substr) {
+        return str.find(substr) != std::string::npos;
+    }
+};
 
 TEST_F(UtilBacktraceCTest, CanCallBacktrace) {
     EXPECT_NO_THROW({ util_backtrace(); });
@@ -20,8 +21,6 @@ TEST_F(UtilBacktraceCTest, PrintsCorrectBacktrace) {
 
     std::string output = testing::internal::GetCapturedStdout();
 
-    EXPECT_TRUE(ContainsSubstring(output, "util_backtrace"));
-    EXPECT_TRUE(ContainsSubstring(output, "libfortran-support"));
-    EXPECT_TRUE(
-        ContainsSubstring(output, "UtilBacktraceCTest_PrintsCorrectBacktrace"));
+    EXPECT_PRED2(ContainsSubstring,output,"util_backtrace");
+    EXPECT_PRED2(ContainsSubstring,output,"libfortran-support");
 }