[clang-format] Ignore case and stable sort using-declarations

Summary:
This ignores case while sorting using-declarations, fixing a case where `_` would appear between lowercase and uppercase characters.
It also applies stable sort, so that replacements for the exact same using declarations are not generated.

Reviewers: klimek, alexfh

Reviewed By: alexfh

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D37263

llvm-svn: 313963

1 files changed, 71 insertions, 0 deletions

diff --git a/clang/unittests/Format/UsingDeclarationsSorterTest.cpp b/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
index 858a62c2d79..219d0302a42 100644
--- a/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
+++ b/clang/unittests/Format/UsingDeclarationsSorterTest.cpp
@@ -86,6 +86,77 @@ TEST_F(UsingDeclarationsSorterTest, SwapsTwoConsecutiveUsingDeclarations) {
                                   "using a, b;"));
 }
 
+TEST_F(UsingDeclarationsSorterTest, SortsCaseInsensitively) {
+  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;"));
+  EXPECT_EQ("using a;\n"
+            "using B;",
+            sortUsingDeclarations("using B;\n"
+                                  "using a;"));
+  EXPECT_EQ("using _;\n"
+            "using a;",
+            sortUsingDeclarations("using a;\n"
+                                  "using _;"));
+  EXPECT_EQ("using a::_;\n"
+            "using a::a;",
+            sortUsingDeclarations("using a::a;\n"
+                                  "using a::_;"));
+
+  EXPECT_EQ("using ::testing::_;\n"
+            "using ::testing::Aardvark;\n"
+            "using ::testing::apple::Honeycrisp;\n"
+            "using ::testing::Xylophone;\n"
+            "using ::testing::zebra::Stripes;",
+            sortUsingDeclarations("using ::testing::Aardvark;\n"
+                                  "using ::testing::Xylophone;\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"