Adding RTCErrorOr class to be used by ORTC APIs.

webrtc/api/rtcerror_unittest.cc

Index: webrtc/api/rtcerror_unittest.cc
diff --git a/webrtc/api/rtcerror_unittest.cc b/webrtc/api/rtcerror_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..32b03add075187eea2353d3dac2053a6dbb998b9
--- /dev/null
+++ b/webrtc/api/rtcerror_unittest.cc
@@ -0,0 +1,241 @@
+/*
+ *  Copyright 2017 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <utility>
+
+#include "webrtc/api/rtcerror.h"
+#include "webrtc/test/gtest.h"
+
+namespace {
+
+const int kDefaultMoveOnlyIntValue = 0xbadf00d;
+
+// Class that has no copy constructor, ensuring that RTCErrorOr can
+struct MoveOnlyInt {
+  MoveOnlyInt() {}
+  explicit MoveOnlyInt(int value) : value(value) {}
+  MoveOnlyInt(const MoveOnlyInt& other) = delete;
+  MoveOnlyInt(MoveOnlyInt&& other) = default;
+  MoveOnlyInt& operator=(MoveOnlyInt&& other) = default;
+
+  int value = kDefaultMoveOnlyIntValue;
+};
+
+// Same as above. Used to test conversion from RTCErrorOr<A> to RTCErrorOr<B>
+// when A can be converted to B.
+struct MoveOnlyInt2 {
+  MoveOnlyInt2() {}
+  explicit MoveOnlyInt2(int value) : value(value) {}
+  MoveOnlyInt2(const MoveOnlyInt2& other) = delete;
+  MoveOnlyInt2(MoveOnlyInt2&& other) = default;
+  MoveOnlyInt2& operator=(MoveOnlyInt2&& other) = default;
+
+  explicit MoveOnlyInt2(MoveOnlyInt&& other) : value(other.value) {}
+  MoveOnlyInt2& operator=(MoveOnlyInt&& other) {
+    value = other.value;
+    return *this;
+  }
+
+  int value = kDefaultMoveOnlyIntValue;
+};
+
+}  // namespace
+
+namespace webrtc {
+
+// Simple test for ostream operator for RTCErrorType.
+TEST(RTCErrorTypeTest, OstreamOperator) {
+  std::ostringstream oss;
+  oss << webrtc::RTCErrorType::NONE << ' '
+      << webrtc::RTCErrorType::INVALID_PARAMETER << ' '
+      << webrtc::RTCErrorType::INTERNAL_ERROR;
+  EXPECT_EQ("NONE INVALID_PARAMETER INTERNAL_ERROR", oss.str());
+}
+
+// Test that the default constructor creates a "no error" error.
+TEST(RTCErrorTest, DefaultConstructor) {
+  RTCError e;
+  EXPECT_EQ(RTCErrorType::NONE, e.type());
+  EXPECT_EQ(std::string(), e.message());
+  EXPECT_TRUE(e.ok());
+}
+
+TEST(RTCErrorTest, NormalConstructors) {
+  RTCError a(RTCErrorType::INVALID_PARAMETER);
+  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER, a.type());
+  EXPECT_EQ(std::string(), a.message());
+
+  // Constructor that takes const char* message.
+  RTCError b(RTCErrorType::UNSUPPORTED_PARAMETER, "foobar");
+  EXPECT_EQ(RTCErrorType::UNSUPPORTED_PARAMETER, b.type());
+  EXPECT_EQ(std::string("foobar"), b.message());
+
+  // Constructor that takes std::string message.
+  RTCError c(RTCErrorType::INVALID_RANGE, std::string("new"));
+  EXPECT_EQ(RTCErrorType::INVALID_RANGE, c.type());
+  EXPECT_EQ(std::string("new"), c.message());
+}
+
+TEST(RTCErrorTest, MoveConstructor) {
+  // Static string.
+  RTCError a(RTCErrorType::INVALID_PARAMETER, "foo");
+  RTCError b(std::move(a));
+  EXPECT_EQ(RTCErrorType::INVALID_PARAMETER, b.type());
+  EXPECT_EQ(std::string("foo"), b.message());
+
+  // Non-static string.
+  RTCError c(RTCErrorType::UNSUPPORTED_PARAMETER, std::string("bar"));
+  RTCError d(std::move(c));
+  EXPECT_EQ(RTCErrorType::UNSUPPORTED_PARAMETER, d.type());
+  EXPECT_EQ(std::string("bar"), d.message());
+}
+
+TEST(RTCErrorTest, MoveAssignment) {
+  // Try all combinations of "is static string"/"is non-static string" moves.
+  RTCError e(RTCErrorType::INVALID_PARAMETER, "foo");
+
+  e = RTCError(RTCErrorType::UNSUPPORTED_PARAMETER, "bar");
+  EXPECT_EQ(RTCErrorType::UNSUPPORTED_PARAMETER, e.type());
+  EXPECT_EQ(std::string("bar"), e.message());
+
+  e = RTCError(RTCErrorType::SYNTAX_ERROR, std::string("baz"));
+  EXPECT_EQ(std::string("baz"), e.message());
+
+  e = RTCError(RTCErrorType::SYNTAX_ERROR, std::string("another"));
+  EXPECT_EQ(std::string("another"), e.message());
+
+  e = RTCError(RTCErrorType::SYNTAX_ERROR, "last");
+  EXPECT_EQ(std::string("last"), e.message());
+}
+
+// Test that the error returned by RTCError::OK() is a "no error" error.
+TEST(RTCErrorTest, OKConstant) {
+  RTCError ok = RTCError::OK();
+  EXPECT_EQ(RTCErrorType::NONE, ok.type());
+  EXPECT_EQ(std::string(), ok.message());
+  EXPECT_TRUE(ok.ok());
+}
+
+// Test that "error.ok()" behaves as expected.
+TEST(RTCErrorTest, OkMethod) {
+  RTCError success;
+  RTCError failure(RTCErrorType::INTERNAL_ERROR);
+  EXPECT_TRUE(success.ok());
+  EXPECT_FALSE(failure.ok());
+}
+
+// Test that a message can be set using either static const strings or
+// std::strings.
+TEST(RTCErrorTest, SetMessage) {
+  RTCError e;
+  // Try all combinations of "is static string"/"is non-static string" calls.
+  e.set_message("foo");
+  EXPECT_EQ(std::string("foo"), e.message());
+
+  e.set_message("bar");
+  EXPECT_EQ(std::string("bar"), e.message());
+
+  e.set_message(std::string("string"));
+  EXPECT_EQ(std::string("string"), e.message());
+
+  e.set_message(std::string("more"));
+  EXPECT_EQ(std::string("more"), e.message());
+
+  e.set_message("love to test");
+  EXPECT_EQ(std::string("love to test"), e.message());
+}
+
+// Test that the default constructor creates an "INTERNAL_ERROR".
+TEST(RTCErrorOrTest, DefaultConstructor) {
+  RTCErrorOr<MoveOnlyInt> e;
+  EXPECT_EQ(RTCErrorType::INTERNAL_ERROR, e.error().type());
+}
+
+// Test that an RTCErrorOr can be implicitly constructed from a value.
+TEST(RTCErrorOrTest, ImplicitValueConstructor) {
+  RTCErrorOr<MoveOnlyInt> e = [] { return MoveOnlyInt(100); }();
+  EXPECT_EQ(100, e.value().value);
+}
+
+// Test that an RTCErrorOr can be implicitly constructed from an RTCError.
+TEST(RTCErrorOrTest, ImplicitErrorConstructor) {
+  RTCErrorOr<MoveOnlyInt> e = [] {
+    return RTCError(RTCErrorType::SYNTAX_ERROR);
+  }();
+  EXPECT_EQ(RTCErrorType::SYNTAX_ERROR, e.error().type());
+}
+
+TEST(RTCErrorOrTest, MoveConstructor) {
+  RTCErrorOr<MoveOnlyInt> a(MoveOnlyInt(5));
+  RTCErrorOr<MoveOnlyInt> b(std::move(a));
+  EXPECT_EQ(5, b.value().value);
+}
+
+TEST(RTCErrorOrTest, MoveAssignment) {
+  RTCErrorOr<MoveOnlyInt> a(MoveOnlyInt(5));
+  RTCErrorOr<MoveOnlyInt> b(MoveOnlyInt(10));
+  a = std::move(b);
+  EXPECT_EQ(10, a.value().value);
+}
+
+TEST(RTCErrorOrTest, ConversionConstructor) {
+  RTCErrorOr<MoveOnlyInt> a(MoveOnlyInt(1));
+  RTCErrorOr<MoveOnlyInt2> b(std::move(a));
+}
+
+TEST(RTCErrorOrTest, ConversionAssignment) {
+  RTCErrorOr<MoveOnlyInt> a(MoveOnlyInt(5));
+  RTCErrorOr<MoveOnlyInt2> b(MoveOnlyInt2(10));
+  b = std::move(a);
+  EXPECT_EQ(5, b.value().value);
+}
+
+TEST(RTCErrorOrTest, OkMethod) {
+  RTCErrorOr<int> success(1337);
+  RTCErrorOr<int> error = RTCError(RTCErrorType::INTERNAL_ERROR);
+  EXPECT_TRUE(success.ok());
+  EXPECT_FALSE(error.ok());
+}
+
+TEST(RTCErrorOrTest, MoveError) {
+  RTCErrorOr<int> e({RTCErrorType::SYNTAX_ERROR, "message"});
+  RTCError err = e.MoveError();
+  EXPECT_EQ(RTCErrorType::SYNTAX_ERROR, err.type());
+  EXPECT_EQ(std::string("message"), err.message());
+}
+
+TEST(RTCErrorOrTest, MoveValue) {
+  RTCErrorOr<MoveOnlyInt> e(MoveOnlyInt(88));
+  MoveOnlyInt value = e.MoveValue();
+  EXPECT_EQ(88, value.value);
+}
+
+// Death tests.
+// Disabled on Android because death tests misbehave on Android, see
+// base/test/gtest_util.h.
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+TEST(RTCErrorOrDeathTest, ConstructWithOkError) {
+  EXPECT_DEATH(RTCErrorOr<int> err = RTCError::OK(), "");
+}
+
+TEST(RTCErrorOrDeathTest, DereferenceErrorValue) {
+  RTCErrorOr<int> error = RTCError(RTCErrorType::INTERNAL_ERROR);
+  EXPECT_DEATH(error.value(), "");
+}
+
+TEST(RTCErrorOrDeathTest, MoveErrorValue) {
+  RTCErrorOr<int> error = RTCError(RTCErrorType::INTERNAL_ERROR);
+  EXPECT_DEATH(error.MoveValue(), "");
+}
+
+#endif  // RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+}  // namespace webrtc