1 files changed, 93 insertions, 0 deletions
diff --git a/clang/unittests/Tooling/RefactoringTest.cpp b/clang/unittests/Tooling/RefactoringTest.cpp
index 6c2c16b484d..d9a87a5690f 100644
--- a/clang/unittests/Tooling/RefactoringTest.cpp
+++ b/clang/unittests/Tooling/RefactoringTest.cpp
@@ -489,5 +489,98 @@ TEST(DeduplicateTest, detectsConflicts) {
   }
 }
 
+class MergeReplacementsTest : public ::testing::Test {
+protected:
+  void mergeAndTestRewrite(StringRef Code, StringRef Intermediate,
+                           StringRef Result, const Replacements &First,
+                           const Replacements &Second) {
+    // These are mainly to verify the test itself and make it easier to read.
+    std::string AfterFirst = applyAllReplacements(Code, First);
+    std::string InSequenceRewrite = applyAllReplacements(AfterFirst, Second);
+    EXPECT_EQ(Intermediate, AfterFirst);
+    EXPECT_EQ(Result, InSequenceRewrite);
+
+    tooling::Replacements Merged = mergeReplacements(First, Second);
+    std::string MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
+    if (InSequenceRewrite != MergedRewrite)
+      for (tooling::Replacement M : Merged)
+        llvm::errs() << M.getOffset() << " " << M.getLength() << " "
+                     << M.getReplacementText() << "\n";
+  }
+  void mergeAndTestRewrite(StringRef Code, const Replacements &First,
+                           const Replacements &Second) {
+    std::string InSequenceRewrite =
+        applyAllReplacements(applyAllReplacements(Code, First), Second);
+    tooling::Replacements Merged = mergeReplacements(First, Second);
+    std::string MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
+    if (InSequenceRewrite != MergedRewrite)
+      for (tooling::Replacement M : Merged)
+        llvm::errs() << M.getOffset() << " " << M.getLength() << " "
+                     << M.getReplacementText() << "\n";
+  }
+};
+
+TEST_F(MergeReplacementsTest, Offsets) {
+  mergeAndTestRewrite("aaa", "aabab", "cacabab",
+                      {{"", 2, 0, "b"}, {"", 3, 0, "b"}},
+                      {{"", 0, 0, "c"}, {"", 1, 0, "c"}});
+  mergeAndTestRewrite("aaa", "babaa", "babacac",
+                      {{"", 0, 0, "b"}, {"", 1, 0, "b"}},
+                      {{"", 4, 0, "c"}, {"", 5, 0, "c"}});
+  mergeAndTestRewrite("aaaa", "aaa", "aac", {{"", 1, 1, ""}},
+                      {{"", 2, 1, "c"}});
+
+  mergeAndTestRewrite("aa", "bbabba", "bbabcba",
+                      {{"", 0, 0, "bb"}, {"", 1, 0, "bb"}}, {{"", 4, 0, "c"}});
+}
+
+TEST_F(MergeReplacementsTest, Concatenations) {
+  // Basic concatenations. It is important to merge these into a single
+  // replacement to ensure the correct order.
+  EXPECT_EQ((Replacements{{"", 0, 0, "ab"}}),
+            mergeReplacements({{"", 0, 0, "a"}}, {{"", 1, 0, "b"}}));
+  EXPECT_EQ((Replacements{{"", 0, 0, "ba"}}),
+            mergeReplacements({{"", 0, 0, "a"}}, {{"", 0, 0, "b"}}));
+  mergeAndTestRewrite("", "a", "ab", {{"", 0, 0, "a"}}, {{"", 1, 0, "b"}});
+  mergeAndTestRewrite("", "a", "ba", {{"", 0, 0, "a"}}, {{"", 0, 0, "b"}});
+}
+
+TEST_F(MergeReplacementsTest, NotChangingLengths) {
+  mergeAndTestRewrite("aaaa", "abba", "acca", {{"", 1, 2, "bb"}},
+                      {{"", 1, 2, "cc"}});
+  mergeAndTestRewrite("aaaa", "abba", "abcc", {{"", 1, 2, "bb"}},
+                      {{"", 2, 2, "cc"}});
+  mergeAndTestRewrite("aaaa", "abba", "ccba", {{"", 1, 2, "bb"}},
+                      {{"", 0, 2, "cc"}});
+  mergeAndTestRewrite("aaaaaa", "abbdda", "abccda",
+                      {{"", 1, 2, "bb"}, {"", 3, 2, "dd"}}, {{"", 2, 2, "cc"}});
+}
+
+TEST_F(MergeReplacementsTest, OverlappingRanges) {
+  mergeAndTestRewrite("aaa", "bbd", "bcbcd",
+                      {{"", 0, 1, "bb"}, {"", 1, 2, "d"}},
+                      {{"", 1, 0, "c"}, {"", 2, 0, "c"}});
+
+  mergeAndTestRewrite("aaaa", "aabbaa", "acccca", {{"", 2, 0, "bb"}},
+                      {{"", 1, 4, "cccc"}});
+  mergeAndTestRewrite("aaaa", "aababa", "acccca",
+                      {{"", 2, 0, "b"}, {"", 3, 0, "b"}}, {{"", 1, 4, "cccc"}});
+  mergeAndTestRewrite("aaaaaa", "abbbba", "abba", {{"", 1, 4, "bbbb"}},
+                      {{"", 2, 2, ""}});
+  mergeAndTestRewrite("aaaa", "aa", "cc", {{"", 1, 1, ""}, {"", 2, 1, ""}},
+                      {{"", 0, 2, "cc"}});
+  mergeAndTestRewrite("aa", "abbba", "abcbcba", {{"", 1, 0, "bbb"}},
+                      {{"", 2, 0, "c"}, {"", 3, 0, "c"}});
+
+  mergeAndTestRewrite("aaa", "abbab", "ccdd",
+                      {{"", 0, 1, ""}, {"", 2, 0, "bb"}, {"", 3, 0, "b"}},
+                      {{"", 0, 2, "cc"}, {"", 2, 3, "dd"}});
+  mergeAndTestRewrite("aa", "babbab", "ccdd",
+                      {{"", 0, 0, "b"}, {"", 1, 0, "bb"}, {"", 2, 0, "b"}},
+                      {{"", 0, 3, "cc"}, {"", 3, 3, "dd"}});
+}
+
 } // end namespace tooling
 } // end namespace clang