Fix test.

format-test.cc

@@ -281,34 +281,40 @@ TEST(UtilTest, SystemError) {
   EXPECT_EQ(42, e.error_code());
 }
 
-#ifndef _WIN32
-const int TEST_ERROR = EDOM;
-std::string GetTestErrorMessage() { return strerror(TEST_ERROR); }
-#else
-const int TEST_ERROR = ERROR_FILE_EXISTS;
-std::string GetTestErrorMessage() {
-  LPWSTR message = 0;
-  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
-      ERROR_FILE_EXISTS, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-      reinterpret_cast<LPWSTR>(&message), 0, 0);
-  fmt::internal::UTF16ToUTF8 utf8_message(message);
-  LocalFree(message);
-  return fmt::str(utf8_message);
+TEST(UtilTest, ThrowSystemError) {
+  const int TEST_ERROR = EDOM;
+  fmt::SystemError error("", 0);
+  try {
+    fmt::ThrowSystemError(TEST_ERROR, "test {}") << "error";
+  } catch (const fmt::SystemError &e) {
+    error = e;
+  }
+  EXPECT_EQ(str(fmt::Format("test error: {}") << strerror(TEST_ERROR)),
+      error.what());
+  EXPECT_EQ(TEST_ERROR, error.error_code());
 }
-#endif
 
-TEST(UtilTest, ThrowSystemError) {
+#ifdef _WIN32
+TEST(UtilTest, ThrowWinError) {
+  const int TEST_ERROR = ERROR_FILE_EXISTS;
   fmt::SystemError error("", 0);
   try {
     fmt::ThrowSystemError(TEST_ERROR, "test {}") << "error";
   } catch (const fmt::SystemError &e) {
     error = e;
   }
-  EXPECT_EQ(str(fmt::Format("test error: {}") << GetTestErrorMessage()),
+  LPWSTR message = 0;
+  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
+      ERROR_FILE_EXISTS, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+      reinterpret_cast<LPWSTR>(&message), 0, 0);
+  fmt::internal::UTF16ToUTF8 utf8_message(message);
+  LocalFree(message);
+  EXPECT_EQ(str(fmt::Format("test error: {}") << fmt::str(utf8_message)),
       error.what());
   EXPECT_EQ(TEST_ERROR, error.error_code());
 }
+#endif
 
 class TestString {
  private: