1 files changed, 127 insertions, 0 deletions
diff --git a/clangd/unittests/TraceTests.cpp b/clangd/unittests/TraceTests.cpp
new file mode 100644
index 00000000..1871e6ac
--- /dev/null
+++ b/clangd/unittests/TraceTests.cpp
@@ -0,0 +1,127 @@
+//===-- TraceTests.cpp - Tracing unit 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 "Trace.h"
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/Threading.h"
+#include "llvm/Support/YAMLParser.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace clangd {
+namespace {
+
+MATCHER_P(StringNode, Val, "") {
+  if (arg->getType() != llvm::yaml::Node::NK_Scalar) {
+    *result_listener << "is a " << arg->getVerbatimTag();
+    return false;
+  }
+  llvm::SmallString<32> S;
+  return Val == static_cast<llvm::yaml::ScalarNode *>(arg)->getValue(S);
+}
+
+// Checks that N is a Mapping (JS object) with the expected scalar properties.
+// The object must have all the Expected properties, but may have others.
+bool VerifyObject(llvm::yaml::Node &N,
+                  std::map<std::string, std::string> Expected) {
+  auto *M = llvm::dyn_cast<llvm::yaml::MappingNode>(&N);
+  if (!M) {
+    ADD_FAILURE() << "Not an object";
+    return false;
+  }
+  bool Match = true;
+  llvm::SmallString<32> Tmp;
+  for (auto &Prop : *M) {
+    auto *K = llvm::dyn_cast_or_null<llvm::yaml::ScalarNode>(Prop.getKey());
+    if (!K)
+      continue;
+    std::string KS = K->getValue(Tmp).str();
+    auto I = Expected.find(KS);
+    if (I == Expected.end())
+      continue; // Ignore properties with no assertion.
+
+    auto *V = llvm::dyn_cast_or_null<llvm::yaml::ScalarNode>(Prop.getValue());
+    if (!V) {
+      ADD_FAILURE() << KS << " is not a string";
+      Match = false;
+    }
+    std::string VS = V->getValue(Tmp).str();
+    if (VS != I->second) {
+      ADD_FAILURE() << KS << " expected " << I->second << " but actual " << VS;
+      Match = false;
+    }
+    Expected.erase(I);
+  }
+  for (const auto &P : Expected) {
+    ADD_FAILURE() << P.first << " missing, expected " << P.second;
+    Match = false;
+  }
+  return Match;
+}
+
+TEST(TraceTest, SmokeTest) {
+  // Capture some events.
+  std::string JSON;
+  {
+    llvm::raw_string_ostream OS(JSON);
+    auto JSONTracer = trace::createJSONTracer(OS);
+    trace::Session Session(*JSONTracer);
+    {
+      trace::Span Tracer("A");
+      trace::log("B");
+    }
+  }
+
+  // Get the root JSON object using the YAML parser.
+  llvm::SourceMgr SM;
+  llvm::yaml::Stream Stream(JSON, SM);
+  auto Doc = Stream.begin();
+  ASSERT_NE(Doc, Stream.end());
+  auto *Root = llvm::dyn_cast_or_null<llvm::yaml::MappingNode>(Doc->getRoot());
+  ASSERT_NE(Root, nullptr) << "Root should be an object";
+
+  // Check whether we expect thread name events on this platform.
+  llvm::SmallString<32> ThreadName;
+  get_thread_name(ThreadName);
+  bool ThreadsHaveNames = !ThreadName.empty();
+
+  // We expect in order:
+  //   displayTimeUnit: "ns"
+  //   traceEvents: [process name, thread name, start span, log, end span]
+  // (The order doesn't matter, but the YAML parser is awkward to use otherwise)
+  auto Prop = Root->begin();
+  ASSERT_NE(Prop, Root->end()) << "Expected displayTimeUnit property";
+  ASSERT_THAT(Prop->getKey(), StringNode("displayTimeUnit"));
+  EXPECT_THAT(Prop->getValue(), StringNode("ns"));
+  ASSERT_NE(++Prop, Root->end()) << "Expected traceEvents property";
+  EXPECT_THAT(Prop->getKey(), StringNode("traceEvents"));
+  auto *Events =
+      llvm::dyn_cast_or_null<llvm::yaml::SequenceNode>(Prop->getValue());
+  ASSERT_NE(Events, nullptr) << "traceEvents should be an array";
+  auto Event = Events->begin();
+  ASSERT_NE(Event, Events->end()) << "Expected process name";
+  EXPECT_TRUE(VerifyObject(*Event, {{"ph", "M"}, {"name", "process_name"}}));
+  if (ThreadsHaveNames) {
+    ASSERT_NE(++Event, Events->end()) << "Expected thread name";
+    EXPECT_TRUE(VerifyObject(*Event, {{"ph", "M"}, {"name", "thread_name"}}));
+  }
+  ASSERT_NE(++Event, Events->end()) << "Expected log message";
+  EXPECT_TRUE(VerifyObject(*Event, {{"ph", "i"}, {"name", "Log"}}));
+  ASSERT_NE(++Event, Events->end()) << "Expected span end";
+  EXPECT_TRUE(VerifyObject(*Event, {{"ph", "X"}, {"name", "A"}}));
+  ASSERT_EQ(++Event, Events->end());
+  ASSERT_EQ(++Prop, Root->end());
+}
+
+} // namespace
+} // namespace clangd
+} // namespace clang