Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -16466,6 +16466,58 @@
                Style);
 }
 
+TEST_F(FormatTest, LLVMDefaultStyle) {
+  FormatStyle Style = getLLVMStyle();
+  verifyFormat("extern \"C\" {\n"
+               "int foo();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, GNUDefaultStyle) {
+  FormatStyle Style = getGNUStyle();
+  verifyFormat("extern \"C\"\n"
+               "{\n"
+               "  int foo ();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, MozillaDefaultStyle) {
+  FormatStyle Style = getMozillaStyle();
+  verifyFormat("extern \"C\"\n"
+               "{\n"
+               "  int foo();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, GoogleDefaultStyle) {
+  FormatStyle Style = getGoogleStyle();
+  verifyFormat("extern \"C\" {\n"
+               "int foo();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, ChromiumDefaultStyle) {
+  FormatStyle Style = getChromiumStyle(FormatStyle::LanguageKind::LK_Cpp);
+  verifyFormat("extern \"C\" {\n"
+               "int foo();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, MicrosoftDefaultStyle) {
+  FormatStyle Style = getMicrosoftStyle(FormatStyle::LanguageKind::LK_Cpp);
+  verifyFormat("extern \"C\"\n"
+               "{\n"
+               "    int foo();\n"
+               "}",
+               Style);
+}
+TEST_F(FormatTest, WebKitDefaultStyle) {
+  FormatStyle Style = getWebKitStyle();
+  verifyFormat("extern \"C\" {\n"
+               "int foo();\n"
+               "}",
+               Style);
+}
 } // namespace
 } // namespace format
 } // namespace clang