Index: clang/unittests/Rewrite/RewriterTest.cpp
===================================================================
--- clang/unittests/Rewrite/RewriterTest.cpp
+++ clang/unittests/Rewrite/RewriterTest.cpp
@@ -75,6 +75,21 @@
   EXPECT_EQ(T.Rewrite.getRewrittenText(T.makeCharRange(42, 47)), "bar;");
   T.Rewrite.ReplaceText(T.SRange, "0");
   EXPECT_EQ(T.Rewrite.getRewrittenText(T.makeCharRange(42, 47)), "0;");
+
+TEST(Rewriter, RangeSize) {
+  StringRef Code = "void foo(){ }";
+
+  RangeTypeTest T(Code, 0, 13);
+  const auto Len = T.Rewrite.getRangeSize(T.makeCharRange(5, 8).getAsRange(), Rewriter::RewriteOptions{});
+  EXPECT_EQ(Len, 3);
+}
+
+TEST(Rewriter, RewriteRegression) {
+  StringRef Code = "void foo(){ }";
+
+  RangeTypeTest T(Code, 0, 13);
+  T.Rewrite.ReplaceText(T.makeCharRange(5, 8).getAsRange(), "bar");
+  EXPECT_EQ(T.Rewrite.getRewrittenText(T.makeCharRange(0, 13)), "void bar(){ }");
 }
 
 } // anonymous namespace