[Startup Tracing] The TraceConfig class [STALE]

base/trace_event/trace_config_unittest.cc

Index: base/trace_event/trace_config_unittest.cc
diff --git a/base/trace_event/trace_config_unittest.cc b/base/trace_event/trace_config_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fc347217cbededcaaab01dd7be0e3270f356d8dc
--- /dev/null
+++ b/base/trace_event/trace_config_unittest.cc
@@ -0,0 +1,530 @@
+// Copyright (c) 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/trace_event/trace_config.h"
+#include "base/trace_event/trace_event.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace trace_event {
+
+namespace {
+
+const char kDefaultTraceConfigString[] =
+  "{"
+    "\"enable_sampling\":false,"
+    "\"enable_systrace\":false,"
+    "\"excluded_categories\":[\"*Debug\",\"*Test\"],"
+    "\"record_mode\":\"record-until-full\""
+  "}";
+
+}  // namespace
+
+TEST(TraceConfigTest, TraceConfigFromValidLegacyStrings) {
+  // From trace options strings
+  TraceConfig config("", "record-until-full");
+  EXPECT_EQ(RECORD_UNTIL_FULL, config.record_mode_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_STREQ("record-until-full", config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("", "record-continuously");
+  EXPECT_EQ(RECORD_CONTINUOUSLY, config.record_mode_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_STREQ("record-continuously", config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("", "trace-to-console");
+  EXPECT_EQ(ECHO_TO_CONSOLE, config.record_mode_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_STREQ("trace-to-console", config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("", "record-as-much-as-possible");
+  EXPECT_EQ(RECORD_AS_MUCH_AS_POSSIBLE, config.record_mode_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_STREQ("record-as-much-as-possible",
+               config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("", "record-until-full, enable-sampling");
+  EXPECT_EQ(RECORD_UNTIL_FULL, config.record_mode_);
+  EXPECT_TRUE(config.enable_sampling_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_STREQ("record-until-full,enable-sampling",
+               config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("", "enable-systrace, record-continuously");
+  EXPECT_EQ(RECORD_CONTINUOUSLY, config.record_mode_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_TRUE(config.enable_systrace_);
+  EXPECT_STREQ("record-continuously,enable-systrace",
+               config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("",
+                       "enable-systrace, trace-to-console, enable-sampling");
+  EXPECT_EQ(ECHO_TO_CONSOLE, config.record_mode_);
+  EXPECT_TRUE(config.enable_sampling_);
+  EXPECT_TRUE(config.enable_systrace_);
+  EXPECT_STREQ("trace-to-console,enable-sampling,enable-systrace",
+               config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig(
+    "", "record-continuously, record-until-full, trace-to-console");
+  EXPECT_EQ(ECHO_TO_CONSOLE, config.record_mode_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_STREQ("trace-to-console", config.ToTraceOptionsString().c_str());
+
+  // From category filter strings
+  config = TraceConfig("-*Debug,-*Test", "");
+  EXPECT_STREQ("-*Debug,-*Test", config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("included,-excluded,inc_pattern*,-exc_pattern*", "");
+  EXPECT_STREQ("included,inc_pattern*,-excluded,-exc_pattern*",
+               config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("only_inc_cat", "");
+  EXPECT_STREQ("only_inc_cat", config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("-only_exc_cat", "");
+  EXPECT_STREQ("-only_exc_cat", config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("disabled-by-default-cc,-excluded", "");
+  EXPECT_STREQ("disabled-by-default-cc,-excluded",
+               config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("disabled-by-default-cc,included", "");
+  EXPECT_STREQ("included,disabled-by-default-cc",
+               config.ToCategoryFilterString().c_str());
+
+  config = TraceConfig("DELAY(test.Delay1;16),included", "");
+  EXPECT_STREQ("included,DELAY(test.Delay1;16)",
+               config.ToCategoryFilterString().c_str());
+
+  // From both trace options and category filter strings
+  config = TraceConfig("", "");
+  EXPECT_EQ(RECORD_UNTIL_FULL, config.record_mode_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_STREQ("", config.ToCategoryFilterString().c_str());
+  EXPECT_STREQ("record-until-full", config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("included,-excluded,inc_pattern*,-exc_pattern*",
+                       "enable-systrace, trace-to-console, enable-sampling");
+  EXPECT_STREQ("included,inc_pattern*,-excluded,-exc_pattern*",
+               config.ToCategoryFilterString().c_str());
+  EXPECT_STREQ("trace-to-console,enable-sampling,enable-systrace",
+               config.ToTraceOptionsString().c_str());
+
+  // From both trace options and category filter strings with spaces.
+  config = TraceConfig(" included , -excluded, inc_pattern*, ,-exc_pattern*   ",
+                       "enable-systrace, ,trace-to-console, enable-sampling  ");
+  EXPECT_STREQ("included,inc_pattern*,-excluded,-exc_pattern*",
+               config.ToCategoryFilterString().c_str());
+  EXPECT_STREQ("trace-to-console,enable-sampling,enable-systrace",
+               config.ToTraceOptionsString().c_str());
+}
+
+TEST(TraceConfigTest, TraceConfigFromInvalidLegacyStrings) {
+  TraceConfig config("", "foo-bar-baz");
+  EXPECT_EQ(RECORD_UNTIL_FULL, config.record_mode_);
+  EXPECT_FALSE(config.enable_systrace_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_STREQ("", config.ToCategoryFilterString().c_str());
+  EXPECT_STREQ("record-until-full", config.ToTraceOptionsString().c_str());
+
+  config = TraceConfig("arbitrary-category", "foo-bar-baz, enable-systrace");
+  EXPECT_EQ(RECORD_UNTIL_FULL, config.record_mode_);
+  EXPECT_TRUE(config.enable_systrace_);
+  EXPECT_FALSE(config.enable_sampling_);
+  EXPECT_STREQ("arbitrary-category", config.ToCategoryFilterString().c_str());
+  EXPECT_STREQ("record-until-full,enable-systrace",
+               config.ToTraceOptionsString().c_str());
+
+  const char* const configs[] = {
+    "",
+    "DELAY(",
+    "DELAY(;",
+    "DELAY(;)",
+    "DELAY(test.Delay)",
+    "DELAY(test.Delay;)"
+  };
+  for (size_t i = 0; i < arraysize(configs); i++) {
+    TraceConfig tc(configs[i], "");
+    EXPECT_EQ(0u, tc.GetSyntheticDelayValues().size());
+  }
+}
+
+TEST(TraceConfigTest, ConstructDefaultTraceConfig) {
+  // Make sure that upon an empty string, we fall back to the default config.
+  TraceConfig tc;
+  EXPECT_STREQ(kDefaultTraceConfigString, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-*Debug,-*Test", tc.ToCategoryFilterString().c_str());
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("CategoryDebug"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("CategoryTest"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("CategoryDebug,CategoryTest"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("Category1,CategoryDebug"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("CategoryDebug,Category1"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("CategoryTest,Category2"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("not-excluded-category"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("disabled-by-default-cc"));
+}
+
+TEST(TraceConfigTest, TraceConfigFromValidString) {
+  // Using some non-empty config string.
+  const char config_string[] =
+    "{"
+      "\"enable_sampling\":true,"
+      "\"enable_systrace\":true,"
+      "\"excluded_categories\":[\"excluded\",\"exc_pattern*\"],"
+      "\"included_categories\":[\"included\",\"inc_pattern*\"],"
+      "\"record_mode\":\"record-continuously\","
+      "\"synthetic_delays\":[\"test.Delay1;16\",\"test.Delay2;32\"]"
+    "}";
+  TraceConfig tc(config_string);
+  EXPECT_STREQ(config_string, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_CONTINUOUSLY);
+  EXPECT_TRUE(tc.enable_sampling_);
+  EXPECT_TRUE(tc.enable_systrace_);
+  EXPECT_STREQ("included,inc_pattern*,-excluded,-exc_pattern*,"
+               "DELAY(test.Delay1;16),DELAY(test.Delay2;32)",
+               tc.ToCategoryFilterString().c_str());
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("included"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("included,excluded"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("inc_pattern_category"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("exc_pattern_category"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("excluded"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("not-excluded-nor-included"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("Category1,CategoryDebug"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("CategoryDebug,Category1"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("CategoryTest,Category2"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("included,DELAY(test.Delay1;16)"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("DELAY(test.Delay1;16)"));
+  EXPECT_EQ(2u, tc.GetSyntheticDelayValues().size());
+  EXPECT_STREQ("test.Delay1;16", tc.GetSyntheticDelayValues()[0].c_str());
+  EXPECT_STREQ("test.Delay2;32", tc.GetSyntheticDelayValues()[1].c_str());
+
+  // Clear
+  tc.Clear();
+  EXPECT_STREQ(tc.ToString().c_str(),
+               "{"
+                 "\"enable_sampling\":false,"
+                 "\"enable_systrace\":false,"
+                 "\"record_mode\":\"record-until-full\""
+               "}");
+}
+
+TEST(TraceConfigTest, TraceConfigFromInvalidString) {
+  // The config string needs to be a dictionary correctly formatted as a JSON
+  // string. Otherwise, it will fall back to the default initialization.
+  TraceConfig tc("");
+  EXPECT_STREQ(kDefaultTraceConfigString, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-*Debug,-*Test", tc.ToCategoryFilterString().c_str());
+
+  tc = TraceConfig("This is an invalid config string.");
+  EXPECT_STREQ(kDefaultTraceConfigString, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-*Debug,-*Test", tc.ToCategoryFilterString().c_str());
+
+  tc = TraceConfig("[\"This\", \"is\", \"not\", \"a\", \"dictionary\"]");
+  EXPECT_STREQ(kDefaultTraceConfigString, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-*Debug,-*Test", tc.ToCategoryFilterString().c_str());
+
+  tc = TraceConfig("{\"record_mode\": invalid-value-needs-double-quote}");
+  EXPECT_STREQ(kDefaultTraceConfigString, tc.ToString().c_str());
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-*Debug,-*Test", tc.ToCategoryFilterString().c_str());
+
+  // If the config string a dictionary formatted as a JSON string, it will
+  // initialize TraceConfig with best effort.
+  tc = TraceConfig("{}");
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("", tc.ToCategoryFilterString().c_str());
+
+  tc = TraceConfig("{\"arbitrary-key\":\"arbitrary-value\"}");
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("", tc.ToCategoryFilterString().c_str());
+
+  const char invalid_config_string[] =
+    "{"
+      "\"enable_sampling\":\"true\","
+      "\"enable_systrace\":1,"
+      "\"excluded_categories\":[\"excluded\"],"
+      "\"included_categories\":\"not a list\","
+      "\"record_mode\":\"arbitrary-mode\","
+      "\"synthetic_delays\":[\"test.Delay1;16\","
+                            "\"invalid-delay\","
+                            "\"test.Delay2;32\"]"
+    "}";
+  tc = TraceConfig(invalid_config_string);
+  EXPECT_TRUE(tc.record_mode_ == RECORD_UNTIL_FULL);
+  EXPECT_FALSE(tc.enable_sampling_);
+  EXPECT_FALSE(tc.enable_systrace_);
+  EXPECT_STREQ("-excluded,DELAY(test.Delay1;16),DELAY(test.Delay2;32)",
+               tc.ToCategoryFilterString().c_str());
+}
+
+TEST(TraceConfigTest, MergingTraceConfigs) {
+  // Merge
+  TraceConfig tc;
+  TraceConfig tc2("included,-excluded,inc_pattern*,-exc_pattern*", "");
+  tc.Merge(tc2);
+  EXPECT_STREQ("{"
+                 "\"enable_sampling\":false,"
+                 "\"enable_systrace\":false,"
+                 "\"excluded_categories\":["
+                   "\"*Debug\",\"*Test\",\"excluded\",\"exc_pattern*\""
+                 "],"
+                 "\"record_mode\":\"record-until-full\""
+               "}",
+               tc.ToString().c_str());
+
+  tc = TraceConfig("DELAY(test.Delay1;16)", "");
+  tc2 = TraceConfig("DELAY(test.Delay2;32)", "");
+  tc.Merge(tc2);
+  EXPECT_EQ(2u, tc.GetSyntheticDelayValues().size());
+  EXPECT_STREQ("test.Delay1;16", tc.GetSyntheticDelayValues()[0].c_str());
+  EXPECT_STREQ("test.Delay2;32", tc.GetSyntheticDelayValues()[1].c_str());
+}
+
+TEST(TraceConfigTest, IsCategoryGroupEnabled) {
+  // Enabling a disabled- category does not require all categories to be traced
+  // to be included.
+  TraceConfig tc("disabled-by-default-cc,-excluded", "");
+  EXPECT_STREQ("disabled-by-default-cc,-excluded",
+               tc.ToCategoryFilterString().c_str());
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("disabled-by-default-cc"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("some_other_group"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("excluded"));
+
+  // Enabled a disabled- category and also including makes all categories to
+  // be traced require including.
+  tc = TraceConfig("disabled-by-default-cc,included", "");
+  EXPECT_STREQ("included,disabled-by-default-cc",
+               tc.ToCategoryFilterString().c_str());
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("disabled-by-default-cc"));
+  EXPECT_TRUE(tc.IsCategoryGroupEnabled("included"));
+  EXPECT_FALSE(tc.IsCategoryGroupEnabled("other_included"));
+}
+
+TEST(TraceConfigTest, IsEmptyOrContainsLeadingOrTrailingWhitespace) {
+  // Test that IsEmptyOrContainsLeadingOrTrailingWhitespace actually catches
+  // categories that are explicitly forbidden.
+  // This method is called in a DCHECK to assert that we don't have these types
+  // of strings as categories.
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      " bad_category "));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      " bad_category"));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "bad_category "));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "   bad_category"));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "bad_category   "));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "   bad_category   "));
+  EXPECT_TRUE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      ""));
+  EXPECT_FALSE(TraceConfig::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "good_category"));
+}
+
+TEST(TraceOptionsTest, TraceOptionsFromString) {
+  TraceOptions options;
+  EXPECT_TRUE(options.SetFromString("record-until-full"));
+  EXPECT_EQ(RECORD_UNTIL_FULL, options.record_mode);
+  EXPECT_FALSE(options.enable_sampling);
+  EXPECT_FALSE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString("record-continuously"));
+  EXPECT_EQ(RECORD_CONTINUOUSLY, options.record_mode);
+  EXPECT_FALSE(options.enable_sampling);
+  EXPECT_FALSE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString("trace-to-console"));
+  EXPECT_EQ(ECHO_TO_CONSOLE, options.record_mode);
+  EXPECT_FALSE(options.enable_sampling);
+  EXPECT_FALSE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString("record-as-much-as-possible"));
+  EXPECT_EQ(RECORD_AS_MUCH_AS_POSSIBLE, options.record_mode);
+  EXPECT_FALSE(options.enable_sampling);
+  EXPECT_FALSE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString("record-until-full, enable-sampling"));
+  EXPECT_EQ(RECORD_UNTIL_FULL, options.record_mode);
+  EXPECT_TRUE(options.enable_sampling);
+  EXPECT_FALSE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString("enable-systrace,record-continuously"));
+  EXPECT_EQ(RECORD_CONTINUOUSLY, options.record_mode);
+  EXPECT_FALSE(options.enable_sampling);
+  EXPECT_TRUE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString(
+      "enable-systrace, trace-to-console,enable-sampling"));
+  EXPECT_EQ(ECHO_TO_CONSOLE, options.record_mode);
+  EXPECT_TRUE(options.enable_sampling);
+  EXPECT_TRUE(options.enable_systrace);
+
+  EXPECT_TRUE(options.SetFromString(
+      "record-continuously,record-until-full,trace-to-console"));
+  EXPECT_EQ(ECHO_TO_CONSOLE, options.record_mode);
+  EXPECT_FALSE(options.enable_systrace);
+  EXPECT_FALSE(options.enable_sampling);
+
+  EXPECT_TRUE(options.SetFromString(""));
+  EXPECT_EQ(RECORD_UNTIL_FULL, options.record_mode);
+  EXPECT_FALSE(options.enable_systrace);
+  EXPECT_FALSE(options.enable_sampling);
+
+  EXPECT_FALSE(options.SetFromString("foo-bar-baz"));
+}
+
+TEST(TraceOptionsTest, TraceOptionsToString) {
+  // Test that we can intialize TraceOptions from a string got from
+  // TraceOptions.ToString() method to get a same TraceOptions.
+  TraceRecordMode modes[] = {RECORD_UNTIL_FULL,
+                             RECORD_CONTINUOUSLY,
+                             ECHO_TO_CONSOLE,
+                             RECORD_AS_MUCH_AS_POSSIBLE};
+  bool enable_sampling_options[] = {true, false};
+  bool enable_systrace_options[] = {true, false};
+
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 2; ++j) {
+      for (int k = 0; k < 2; ++k) {
+        TraceOptions original_option = TraceOptions(modes[i]);
+        original_option.enable_sampling = enable_sampling_options[j];
+        original_option.enable_systrace = enable_systrace_options[k];
+        TraceOptions new_options;
+        EXPECT_TRUE(new_options.SetFromString(original_option.ToString()));
+        EXPECT_EQ(original_option.record_mode, new_options.record_mode);
+        EXPECT_EQ(original_option.enable_sampling, new_options.enable_sampling);
+        EXPECT_EQ(original_option.enable_systrace, new_options.enable_systrace);
+      }
+    }
+  }
+}
+
+// Test the category filter.
+TEST(CategoryFilterTest, CategoryFilter) {
+  // Using the default filter.
+  CategoryFilter default_cf = CategoryFilter(
+      CategoryFilter::kDefaultCategoryFilterString);
+  std::string category_filter_str = default_cf.ToString();
+  EXPECT_STREQ("-*Debug,-*Test", category_filter_str.c_str());
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("not-excluded-category"));
+  EXPECT_FALSE(
+      default_cf.IsCategoryGroupEnabled("disabled-by-default-category"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("Category1,CategoryDebug"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("CategoryDebug,Category1"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("CategoryTest,Category2"));
+
+  // Make sure that upon an empty string, we fall back to the default filter.
+  default_cf = CategoryFilter();
+  category_filter_str = default_cf.ToString();
+  EXPECT_STREQ("-*Debug,-*Test", category_filter_str.c_str());
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("not-excluded-category"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("Category1,CategoryDebug"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("CategoryDebug,Category1"));
+  EXPECT_TRUE(default_cf.IsCategoryGroupEnabled("CategoryTest,Category2"));
+
+  // Using an arbitrary non-empty filter.
+  CategoryFilter cf("included,-excluded,inc_pattern*,-exc_pattern*");
+  category_filter_str = cf.ToString();
+  EXPECT_STREQ("included,inc_pattern*,-excluded,-exc_pattern*",
+               category_filter_str.c_str());
+  EXPECT_TRUE(cf.IsCategoryGroupEnabled("included"));
+  EXPECT_TRUE(cf.IsCategoryGroupEnabled("inc_pattern_category"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("exc_pattern_category"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("excluded"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("not-excluded-nor-included"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("Category1,CategoryDebug"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("CategoryDebug,Category1"));
+  EXPECT_FALSE(cf.IsCategoryGroupEnabled("CategoryTest,Category2"));
+
+  cf.Merge(default_cf);
+  category_filter_str = cf.ToString();
+  EXPECT_STREQ("-excluded,-exc_pattern*,-*Debug,-*Test",
+                category_filter_str.c_str());
+  cf.Clear();
+
+  CategoryFilter reconstructed_cf(category_filter_str);
+  category_filter_str = reconstructed_cf.ToString();
+  EXPECT_STREQ("-excluded,-exc_pattern*,-*Debug,-*Test",
+               category_filter_str.c_str());
+
+  // One included category.
+  CategoryFilter one_inc_cf("only_inc_cat");
+  category_filter_str = one_inc_cf.ToString();
+  EXPECT_STREQ("only_inc_cat", category_filter_str.c_str());
+
+  // One excluded category.
+  CategoryFilter one_exc_cf("-only_exc_cat");
+  category_filter_str = one_exc_cf.ToString();
+  EXPECT_STREQ("-only_exc_cat", category_filter_str.c_str());
+
+  // Enabling a disabled- category does not require all categories to be traced
+  // to be included.
+  CategoryFilter disabled_cat("disabled-by-default-cc,-excluded");
+  EXPECT_STREQ("disabled-by-default-cc,-excluded",
+               disabled_cat.ToString().c_str());
+  EXPECT_TRUE(disabled_cat.IsCategoryGroupEnabled("disabled-by-default-cc"));
+  EXPECT_TRUE(disabled_cat.IsCategoryGroupEnabled("some_other_group"));
+  EXPECT_FALSE(disabled_cat.IsCategoryGroupEnabled("excluded"));
+
+  // Enabled a disabled- category and also including makes all categories to
+  // be traced require including.
+  CategoryFilter disabled_inc_cat("disabled-by-default-cc,included");
+  EXPECT_STREQ("included,disabled-by-default-cc",
+               disabled_inc_cat.ToString().c_str());
+  EXPECT_TRUE(
+      disabled_inc_cat.IsCategoryGroupEnabled("disabled-by-default-cc"));
+  EXPECT_TRUE(disabled_inc_cat.IsCategoryGroupEnabled("included"));
+  EXPECT_FALSE(disabled_inc_cat.IsCategoryGroupEnabled("other_included"));
+
+  // Test that IsEmptyOrContainsLeadingOrTrailingWhitespace actually catches
+  // categories that are explicitly forbiden.
+  // This method is called in a DCHECK to assert that we don't have these types
+  // of strings as categories.
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      " bad_category "));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      " bad_category"));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "bad_category "));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "   bad_category"));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "bad_category   "));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "   bad_category   "));
+  EXPECT_TRUE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      ""));
+  EXPECT_FALSE(CategoryFilter::IsEmptyOrContainsLeadingOrTrailingWhitespace(
+      "good_category"));
+}
+
+}  // namespace trace_event
+}  // namespace base