Index: clang-tools-extra/trunk/clangd/SemanticHighlighting.h
===================================================================
--- clang-tools-extra/trunk/clangd/SemanticHighlighting.h
+++ clang-tools-extra/trunk/clangd/SemanticHighlighting.h
@@ -18,6 +18,7 @@
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_SEMANTICHIGHLIGHTING_H
 
 #include "Protocol.h"
+#include "llvm/Support/raw_ostream.h"
 
 namespace clang {
 namespace clangd {
@@ -42,6 +43,7 @@
 
   NumKinds,
 };
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingKind K);
 
 // Contains all information needed for the highlighting a token.
 struct HighlightingToken {
Index: clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp
+++ clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp
@@ -351,6 +351,43 @@
 }
 } // namespace
 
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingKind K) {
+  switch (K) {
+  case HighlightingKind::Variable:
+    return OS << "Variable";
+  case HighlightingKind::LocalVariable:
+    return OS << "LocalVariable";
+  case HighlightingKind::Parameter:
+    return OS << "Parameter";
+  case HighlightingKind::Function:
+    return OS << "Function";
+  case HighlightingKind::Method:
+    return OS << "Method";
+  case HighlightingKind::StaticMethod:
+    return OS << "StaticMethod";
+  case HighlightingKind::Field:
+    return OS << "Field";
+  case HighlightingKind::StaticField:
+    return OS << "StaticField";
+  case HighlightingKind::Class:
+    return OS << "Class";
+  case HighlightingKind::Enum:
+    return OS << "Enum";
+  case HighlightingKind::EnumConstant:
+    return OS << "EnumConstant";
+  case HighlightingKind::Namespace:
+    return OS << "Namespace";
+  case HighlightingKind::TemplateParameter:
+    return OS << "TemplateParameter";
+  case HighlightingKind::Primitive:
+    return OS << "Primitive";
+  case HighlightingKind::Macro:
+    return OS << "Macro";
+  case HighlightingKind::NumKinds:
+    llvm_unreachable("NumKinds is not a valid HighlightingKind");
+  }
+}
+
 std::vector<LineHighlightings>
 diffHighlightings(ArrayRef<HighlightingToken> New,
                   ArrayRef<HighlightingToken> Old) {
Index: clang-tools-extra/trunk/clangd/unittests/SemanticHighlightingTests.cpp
===================================================================
--- clang-tools-extra/trunk/clangd/unittests/SemanticHighlightingTests.cpp
+++ clang-tools-extra/trunk/clangd/unittests/SemanticHighlightingTests.cpp
@@ -10,9 +10,14 @@
 #include "ClangdServer.h"
 #include "Protocol.h"
 #include "SemanticHighlighting.h"
+#include "SourceCode.h"
 #include "TestFS.h"
 #include "TestTU.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
 #include "gmock/gmock.h"
+#include <algorithm>
 
 namespace clang {
 namespace clangd {
@@ -59,6 +64,36 @@
   return ExpectedTokens;
 }
 
+/// Annotates the input code with provided semantic highlightings. Results look
+/// something like:
+///   class $Class[[X]] {
+///     $Primitive[[int]] $Field[[a]] = 0;
+///   };
+std::string annotate(llvm::StringRef Input,
+                     llvm::ArrayRef<HighlightingToken> Tokens) {
+  assert(std::is_sorted(
+      Tokens.begin(), Tokens.end(),
+      [](const HighlightingToken &L, const HighlightingToken &R) {
+        return L.R.start < R.R.start;
+      }));
+
+  std::string Result;
+  unsigned NextChar = 0;
+  for (auto &T : Tokens) {
+    unsigned StartOffset = llvm::cantFail(positionToOffset(Input, T.R.start));
+    unsigned EndOffset = llvm::cantFail(positionToOffset(Input, T.R.end));
+    assert(StartOffset <= EndOffset);
+    assert(NextChar <= StartOffset);
+
+    Result += Input.substr(NextChar, StartOffset - NextChar);
+    Result += llvm::formatv("${0}[[{1}]]", T.Kind,
+                            Input.substr(StartOffset, EndOffset - StartOffset));
+    NextChar = EndOffset;
+  }
+  Result += Input.substr(NextChar);
+  return Result;
+}
+
 void checkHighlightings(llvm::StringRef Code,
                         std::vector<std::pair</*FileName*/ llvm::StringRef,
                                               /*FileContent*/ llvm::StringRef>>
@@ -68,8 +103,8 @@
   for (auto File : AdditionalFiles)
     TU.AdditionalFiles.insert({File.first, File.second});
   auto AST = TU.build();
-  std::vector<HighlightingToken> ActualTokens = getSemanticHighlightings(AST);
-  EXPECT_THAT(ActualTokens, getExpectedTokens(Test)) << Code;
+
+  EXPECT_EQ(Code, annotate(Test.code(), getSemanticHighlightings(AST)));
 }
 
 // Any annotations in OldCode and NewCode are converted into their corresponding