Add VLOG and friends

These are methods for configurable verbose logging

PiperOrigin-RevId: 588059727
Change-Id: Ib3703edd2493050a5da8b30e88b21adc643b1f7f

1 files changed, 175 insertions, 0 deletions

diff --git a/absl/log/vlog_is_on_test.cc b/absl/log/vlog_is_on_test.cc
new file mode 100644
index 00000000..28a2eea1
--- /dev/null
+++ b/absl/log/vlog_is_on_test.cc
@@ -0,0 +1,175 @@
+// Copyright 2023 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/log/vlog_is_on.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/log_severity.h"
+#include "absl/flags/flag.h"
+#include "absl/log/flags.h"
+#include "absl/log/log.h"
+#include "absl/log/scoped_mock_log.h"
+#include "absl/types/optional.h"
+
+namespace {
+
+using ::testing::_;
+
+absl::optional<int> MaxLogVerbosity() {
+#ifdef ABSL_MAX_VLOG_VERBOSITY
+  return ABSL_MAX_VLOG_VERBOSITY;
+#else
+  return absl::nullopt;
+#endif
+}
+
+absl::optional<int> MinLogLevel() {
+#ifdef ABSL_MIN_LOG_LEVEL
+  return static_cast<int>(ABSL_MIN_LOG_LEVEL);
+#else
+  return absl::nullopt;
+#endif
+}
+
+TEST(VLogIsOn, GlobalWorksWithoutMaxVerbosityAndMinLogLevel) {
+  if (MaxLogVerbosity().has_value() || MinLogLevel().has_value()) {
+    GTEST_SKIP();
+  }
+
+  absl::SetGlobalVLogLevel(3);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "important"));
+
+  log.StartCapturingLogs();
+  VLOG(3) << "important";
+  VLOG(4) << "spam";
+}
+
+TEST(VLogIsOn, FileWorksWithoutMaxVerbosityAndMinLogLevel) {
+  if (MaxLogVerbosity().has_value() || MinLogLevel().has_value()) {
+    GTEST_SKIP();
+  }
+
+  absl::SetVLogLevel("vlog_is_on_test", 3);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "important"));
+
+  log.StartCapturingLogs();
+  VLOG(3) << "important";
+  VLOG(4) << "spam";
+}
+
+TEST(VLogIsOn, PatternWorksWithoutMaxVerbosityAndMinLogLevel) {
+  if (MaxLogVerbosity().has_value() || MinLogLevel().has_value()) {
+    GTEST_SKIP();
+  }
+
+  absl::SetVLogLevel("vlog_is_on*", 3);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "important"));
+
+  log.StartCapturingLogs();
+  VLOG(3) << "important";
+  VLOG(4) << "spam";
+}
+
+TEST(VLogIsOn, GlobalDoesNotFilterBelowMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() < 2) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetGlobalVLogLevel(1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "asdf"));
+
+  log.StartCapturingLogs();
+  VLOG(2) << "asdf";
+}
+
+TEST(VLogIsOn, FileDoesNotFilterBelowMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() < 2) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetVLogLevel("vlog_is_on_test", 1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "asdf"));
+
+  log.StartCapturingLogs();
+  VLOG(2) << "asdf";
+}
+
+TEST(VLogIsOn, PatternDoesNotFilterBelowMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() < 2) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetVLogLevel("vlog_is_on*", 1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  EXPECT_CALL(log, Log(absl::LogSeverity::kInfo, _, "asdf"));
+
+  log.StartCapturingLogs();
+  VLOG(2) << "asdf";
+}
+
+TEST(VLogIsOn, GlobalFiltersAboveMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() >= 4) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetGlobalVLogLevel(1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  log.StartCapturingLogs();
+  VLOG(4) << "dfgh";
+}
+
+TEST(VLogIsOn, FileFiltersAboveMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() >= 4) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetVLogLevel("vlog_is_on_test", 1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  log.StartCapturingLogs();
+  VLOG(4) << "dfgh";
+}
+
+TEST(VLogIsOn, PatternFiltersAboveMaxVerbosity) {
+  if (!MaxLogVerbosity().has_value() || *MaxLogVerbosity() >= 4) {
+    GTEST_SKIP();
+  }
+
+  // Set an arbitrary high value to avoid filtering VLOGs in tests by default.
+  absl::SetVLogLevel("vlog_is_on*", 1000);
+  absl::ScopedMockLog log(absl::MockLogDefault::kDisallowUnexpected);
+
+  log.StartCapturingLogs();
+  VLOG(4) << "dfgh";
+}
+
+}  // namespace