[clangd] Improve output of semantic highlighting tests in case of failures

[ilya-biryukov]

Summary

Instead of matching lists of highlightings, we annotate input code with
resulting highlightings and diff it against the expected annotated input.

In case of failures, this produces much nicer output in form of text-based
diffs.

[hokein]

nice, thanks.

clang-tools-extra/trunk/clangd/SemanticHighlighting.h

 // calls etc.).
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_SEMANTICHIGHLIGHTING_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_SEMANTICHIGHLIGHTING_H
 
 #include "Protocol.h"
+#include "llvm/Support/raw_ostream.h"
 
 namespace clang {
 namespace clangd {
 class ParsedAST;
 
 enum class HighlightingKind {
   Variable = 0,
   LocalVariable,
   Parameter,
   Function,
   Method,
   StaticMethod,
   Field,
   StaticField,
   Class,
   Enum,
   EnumConstant,
   Namespace,
   TemplateParameter,
   Primitive,
   Macro,
 
   NumKinds,
 };
+llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, HighlightingKind K);
 
 // Contains all information needed for the highlighting a token.
 struct HighlightingToken {
   HighlightingKind Kind;
   Range R;
 };
 
 bool operator==(const HighlightingToken &L, const HighlightingToken &R);

clang-tools-extra/trunk/clangd/SemanticHighlighting.cpp

takeLine(ArrayRef<HighlightingToken> AllTokens,
          ArrayRef<HighlightingToken>::iterator StartLineIt, int Line) {
   return ArrayRef<HighlightingToken>(StartLineIt, AllTokens.end())
       .take_while([Line](const HighlightingToken &Token) {
         return Token.R.start.line == Line;
       });
 }
 } // 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) {
   assert(std::is_sorted(New.begin(), New.end()) &&
          "New must be a sorted vector");
   assert(std::is_sorted(Old.begin(), Old.end()) &&
          "Old must be a sorted vector");
 

clang-tools-extra/trunk/clangd/unittests/SemanticHighlightingTests.cpp

 //==- SemanticHighlightingTests.cpp - SemanticHighlighting tests-*- C++ -* -==//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "Annotations.h"
 #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 {
 namespace {
 
 MATCHER_P(LineNumber, L, "") { return arg.Line == L; }
 MATCHER(EmptyHighlightings, "") { return arg.Tokens.empty(); }
 
for (const auto &KindString : KindToString) {
     std::vector<HighlightingToken> Toks = makeHighlightingTokens(
         Test.ranges(KindString.second), KindString.first);
     ExpectedTokens.insert(ExpectedTokens.end(), Toks.begin(), Toks.end());
   }
   llvm::sort(ExpectedTokens);
   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>>
                             AdditionalFiles = {}) {
   Annotations Test(Code);
   auto TU = TestTU::withCode(Test.code());
   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
 // HighlightingToken. The tokens are diffed against each other. Any lines where
 // the tokens should diff must be marked with a ^ somewhere on that line in
 // NewCode. If there are diffs that aren't marked with ^ the test fails. The
 // test also fails if there are lines marked with ^ that don't differ.
 void checkDiffedHighlights(llvm::StringRef OldCode, llvm::StringRef NewCode) {
EXPECT_THAT(ActualDiff,
               testing::UnorderedElementsAre(
                   testing::AllOf(LineNumber(3), EmptyHighlightings()),
                   testing::AllOf(LineNumber(4), EmptyHighlightings())));
 }
 
 } // namespace
 } // namespace clangd
 } // namespace clang
 No newline at end of file