Test improvements:

- Update files with \r\n newlines.
- Require clang 4.0.0 for running tests.

src/indexer.cc

@@ -1868,3 +1868,7 @@ void ClangSanityCheck() {
   clang_disposeTranslationUnit(tu);
   clang_disposeIndex(index);
 }
+
+std::string GetClangVersion() {
+  return ToString(clang_getClangVersion());
+}

src/indexer.h

@@ -559,3 +559,5 @@ std::vector<std::unique_ptr<IndexFile>> ParseWithTu(
 void IndexInit();
 
 void ClangSanityCheck();
+
+std::string GetClangVersion();

src/test.cc

@@ -19,7 +19,8 @@ std::string ToString(const rapidjson::Document& document) {
 
   buffer.Clear();
   document.Accept(writer);
-  return buffer.GetString();
+  std::string output = buffer.GetString();
+  return UpdateToRnNewlines(output);
 }
 
 void DiffDocuments(std::string path,
@@ -110,7 +111,16 @@ IndexFile* FindDbForPathEnding(
 void RunIndexTests(const std::string& filter_path) {
   SetTestOutputMode();
 
-  // TODO: Assert that we need to be on clang >= 3.9.1
+  // Index tests change based on the version of clang used.
+  static constexpr const char* kRequiredClangVersion =
+      "clang version 4.0.0 (tags/RELEASE_400/final)";
+  if (GetClangVersion() != kRequiredClangVersion) {
+    std::cerr << "Index tests must be run using clang version \""
+              << kRequiredClangVersion << "\" (cquery is running with \""
+              << GetClangVersion() << "\")" << std::endl;
+    exit(1);
+  }
+
   bool update_all = false;
   ClangIndex index;
 
@@ -230,8 +240,9 @@ void RunIndexTests(const std::string& filter_path) {
             update_all = true;
 
           if (update_all || c == 'u') {
-            UpdateTestExpectation(path, expected_output,
+            // Note: we use |entry.second| instead of |expected_output| because
-                                  ToString(actual) + "\n");
+            // |expected_output| has had text replacements applied.
+            UpdateTestExpectation(path, entry.second, ToString(actual) + "\n");
           }
         }
       }

src/utils.cc

@@ -502,6 +502,28 @@ std::string GetDefaultResourceDirectory() {
   return NormalizePath(result);
 }
 
+std::string UpdateToRnNewlines(std::string output) {
+  size_t idx = 0;
+  while (true) {
+    idx = output.find('\n', idx);
+
+    // No more matches.
+    if (idx == std::string::npos)
+      break;
+
+    // Skip an existing "\r\n" match.
+    if (idx > 0 && output[idx - 1] == '\r') {
+      ++idx;
+      continue;
+    }
+
+    // Replace "\n" with "\r|n".
+    output.replace(output.begin() + idx, output.begin() + idx + 1, "\r\n");
+  }
+
+  return output;
+};
+
 TEST_SUITE("ParseTestExpectation") {
   TEST_CASE("Parse TEXT_REPLACE") {
     // clang-format off
@@ -552,3 +574,15 @@ TEST_SUITE("ParseTestExpectation") {
     REQUIRE(replacer.Apply("foofoobar0123") == "barbarbar22456");
   }
 }
+
+TEST_SUITE("Update \\n to \\r\\n") {
+  TEST_CASE("all") {
+    REQUIRE(UpdateToRnNewlines("\n") == "\r\n");
+    REQUIRE(UpdateToRnNewlines("\n\n") == "\r\n\r\n");
+    REQUIRE(UpdateToRnNewlines("\r\n\n") == "\r\n\r\n");
+    REQUIRE(UpdateToRnNewlines("\n\r\n") == "\r\n\r\n");
+    REQUIRE(UpdateToRnNewlines("\r\n\r\n") == "\r\n\r\n");
+    REQUIRE(UpdateToRnNewlines("f1\nfo2\nfoo3") == "f1\r\nfo2\r\nfoo3");
+    REQUIRE(UpdateToRnNewlines("f1\r\nfo2\r\nfoo3") == "f1\r\nfo2\r\nfoo3");
+  }
+}

src/utils.h

@@ -181,3 +181,6 @@ float GetProcessMemoryUsedInMb();
 std::string FormatMicroseconds(long long microseconds);
 
 std::string GetDefaultResourceDirectory();
+
+// Makes sure all newlines in |output| are in \r\n format.
+std::string UpdateToRnNewlines(std::string output);