1 files changed, 61 insertions, 10 deletions
diff --git a/clang/unittests/Format/UsingDeclarationsSorterTest.cpp b/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
index 6ce96ed9620..e72076a8e31 100644
--- a/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
+++ b/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
@@ -50,8 +50,8 @@ TEST_F(UsingDeclarationsSorterTest, SwapsTwoConsecutiveUsingDeclarations) {
             "using aa;",
             sortUsingDeclarations("using aa;\n"
                                   "using a;"));
-  EXPECT_EQ("using ::a;\n"
-            "using a;",
+  EXPECT_EQ("using a;\n"
+            "using ::a;",
             sortUsingDeclarations("using a;\n"
                                   "using ::a;"));
 
@@ -86,21 +86,32 @@ TEST_F(UsingDeclarationsSorterTest, SwapsTwoConsecutiveUsingDeclarations) {
                                   "using a, b;"));
 }
 
-TEST_F(UsingDeclarationsSorterTest, SortsCaseSensitively) {
+TEST_F(UsingDeclarationsSorterTest, UsingDeclarationOrder) {
   EXPECT_EQ("using A;\n"
             "using a;",
             sortUsingDeclarations("using A;\n"
                                   "using a;"));
-  EXPECT_EQ("using A;\n"
-            "using a;",
+  EXPECT_EQ("using a;\n"
+            "using A;",
             sortUsingDeclarations("using a;\n"
                                   "using A;"));
-  EXPECT_EQ("using B;\n"
-            "using a;",
+  EXPECT_EQ("using a;\n"
+            "using B;",
             sortUsingDeclarations("using B;\n"
                                   "using a;"));
 
-  // Sorts '_' right before 'A'.
+  // Ignores leading '::'.
+  EXPECT_EQ("using ::a;\n"
+            "using A;",
+            sortUsingDeclarations("using ::a;\n"
+                                  "using A;"));
+
+  EXPECT_EQ("using ::A;\n"
+            "using a;",
+            sortUsingDeclarations("using ::A;\n"
+                                  "using a;"));
+
+  // Sorts '_' before 'a' and 'A'.
   EXPECT_EQ("using _;\n"
             "using A;",
             sortUsingDeclarations("using A;\n"
@@ -114,18 +125,58 @@ TEST_F(UsingDeclarationsSorterTest, SortsCaseSensitively) {
             sortUsingDeclarations("using a::a;\n"
                                   "using a::_;"));
 
+  // Sorts non-namespace names before namespace names at the same level.
   EXPECT_EQ("using ::testing::_;\n"
             "using ::testing::Aardvark;\n"
+            "using ::testing::kMax;\n"
             "using ::testing::Xylophone;\n"
             "using ::testing::apple::Honeycrisp;\n"
             "using ::testing::zebra::Stripes;",
             sortUsingDeclarations("using ::testing::Aardvark;\n"
                                   "using ::testing::Xylophone;\n"
+                                  "using ::testing::kMax;\n"
                                   "using ::testing::_;\n"
                                   "using ::testing::apple::Honeycrisp;\n"
                                   "using ::testing::zebra::Stripes;"));
 }
 
+TEST_F(UsingDeclarationsSorterTest, SortsStably) {
+  EXPECT_EQ("using a;\n"
+            "using a;\n"
+            "using A;\n"
+            "using a;\n"
+            "using A;\n"
+            "using a;\n"
+            "using A;\n"
+            "using a;\n"
+            "using B;\n"
+            "using b;\n"
+            "using b;\n"
+            "using B;\n"
+            "using b;\n"
+            "using b;\n"
+            "using b;\n"
+            "using B;\n"
+            "using b;",
+            sortUsingDeclarations("using a;\n"
+                                  "using B;\n"
+                                  "using a;\n"
+                                  "using b;\n"
+                                  "using A;\n"
+                                  "using a;\n"
+                                  "using b;\n"
+                                  "using B;\n"
+                                  "using b;\n"
+                                  "using A;\n"
+                                  "using a;\n"
+                                  "using b;\n"
+                                  "using b;\n"
+                                  "using B;\n"
+                                  "using b;\n"
+                                  "using A;\n"
+                                  "using a;"));
+}
+
 TEST_F(UsingDeclarationsSorterTest, SortsMultipleTopLevelDeclarations) {
   EXPECT_EQ("using a;\n"
             "using b;\n"
@@ -139,14 +190,14 @@ TEST_F(UsingDeclarationsSorterTest, SortsMultipleTopLevelDeclarations) {
                                   "using c;"));
 
   EXPECT_EQ("#include <iostream>\n"
-            "using ::std::endl;\n"
             "using std::cin;\n"
             "using std::cout;\n"
+            "using ::std::endl;\n"
             "int main();",
             sortUsingDeclarations("#include <iostream>\n"
                                   "using std::cout;\n"
-                                  "using std::cin;\n"
                                   "using ::std::endl;\n"
+                                  "using std::cin;\n"
                                   "int main();"));
 }