Adds `AbslStringify` to `absl::Status` for completeness.

This also adds a test for `operator<<`.

PiperOrigin-RevId: 568590367
Change-Id: Ia0ad39cb582e7d24e6c4131827818d8c4b10dfd9

absl/status/BUILD.bazel

@@ -70,6 +70,7 @@ cc_test(
         ":status",
         "//absl/strings",
         "//absl/strings:cord",
+        "//absl/strings:str_format",
         "@com_google_googletest//:gtest_main",
     ],
 )

absl/status/CMakeLists.txt

@@ -56,6 +56,7 @@ absl_cc_test(
     ${ABSL_TEST_COPTS}
   DEPS
     absl::status
+    absl::str_format
     absl::strings
     GTest::gmock_main
 )

absl/status/status.h

@@ -64,7 +64,6 @@
 #include "absl/functional/function_ref.h"
 #include "absl/status/internal/status_internal.h"
 #include "absl/strings/cord.h"
-#include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 
@@ -523,6 +522,12 @@ class Status final {
   std::string ToString(
       StatusToStringMode mode = StatusToStringMode::kDefault) const;
 
+  // Support `absl::StrCat`, `absl::StrFormat`, etc.
+  template <typename Sink>
+  friend void AbslStringify(Sink& sink, const Status& status) {
+    sink.Append(status.ToString(StatusToStringMode::kWithEverything));
+  }
+
   // Status::IgnoreError()
   //
   // Ignores any errors. This method does nothing except potentially suppress

absl/status/status_test.cc

@@ -25,6 +25,7 @@
 #include "gtest/gtest.h"
 #include "absl/strings/cord.h"
 #include "absl/strings/str_cat.h"
+#include "absl/strings/str_format.h"
 
 namespace {
 
@@ -305,37 +306,77 @@ TEST(Status, TestForEachPayload) {
 }
 
 TEST(Status, ToString) {
-  absl::Status s(absl::StatusCode::kInternal, "fail");
-  EXPECT_EQ("INTERNAL: fail", s.ToString());
-  s.SetPayload("foo", absl::Cord("bar"));
-  EXPECT_EQ("INTERNAL: fail [foo='bar']", s.ToString());
-  s.SetPayload("bar", absl::Cord("\377"));
-  EXPECT_THAT(s.ToString(),
+  absl::Status status(absl::StatusCode::kInternal, "fail");
+  EXPECT_EQ("INTERNAL: fail", status.ToString());
+  status.SetPayload("foo", absl::Cord("bar"));
+  EXPECT_EQ("INTERNAL: fail [foo='bar']", status.ToString());
+  status.SetPayload("bar", absl::Cord("\377"));
+  EXPECT_THAT(status.ToString(),
               AllOf(HasSubstr("INTERNAL: fail"), HasSubstr("[foo='bar']"),
                     HasSubstr("[bar='\\xff']")));
 }
 
 TEST(Status, ToStringMode) {
-  absl::Status s(absl::StatusCode::kInternal, "fail");
-  s.SetPayload("foo", absl::Cord("bar"));
-  s.SetPayload("bar", absl::Cord("\377"));
+  absl::Status status(absl::StatusCode::kInternal, "fail");
+  status.SetPayload("foo", absl::Cord("bar"));
+  status.SetPayload("bar", absl::Cord("\377"));
 
   EXPECT_EQ("INTERNAL: fail",
-            s.ToString(absl::StatusToStringMode::kWithNoExtraData));
+            status.ToString(absl::StatusToStringMode::kWithNoExtraData));
 
-  EXPECT_THAT(s.ToString(absl::StatusToStringMode::kWithPayload),
+  EXPECT_THAT(status.ToString(absl::StatusToStringMode::kWithPayload),
               AllOf(HasSubstr("INTERNAL: fail"), HasSubstr("[foo='bar']"),
                     HasSubstr("[bar='\\xff']")));
 
-  EXPECT_THAT(s.ToString(absl::StatusToStringMode::kWithEverything),
+  EXPECT_THAT(status.ToString(absl::StatusToStringMode::kWithEverything),
               AllOf(HasSubstr("INTERNAL: fail"), HasSubstr("[foo='bar']"),
                     HasSubstr("[bar='\\xff']")));
 
-  EXPECT_THAT(s.ToString(~absl::StatusToStringMode::kWithPayload),
+  EXPECT_THAT(status.ToString(~absl::StatusToStringMode::kWithPayload),
               AllOf(HasSubstr("INTERNAL: fail"), Not(HasSubstr("[foo='bar']")),
                     Not(HasSubstr("[bar='\\xff']"))));
 }
 
+TEST(Status, OstreamOperator) {
+  absl::Status status(absl::StatusCode::kInternal, "fail");
+  { std::stringstream stream;
+    stream << status;
+    EXPECT_EQ("INTERNAL: fail", stream.str());
+  }
+  status.SetPayload("foo", absl::Cord("bar"));
+  { std::stringstream stream;
+    stream << status;
+    EXPECT_EQ("INTERNAL: fail [foo='bar']", stream.str());
+  }
+  status.SetPayload("bar", absl::Cord("\377"));
+  { std::stringstream stream;
+    stream << status;
+    EXPECT_THAT(stream.str(),
+                AllOf(HasSubstr("INTERNAL: fail"), HasSubstr("[foo='bar']"),
+                      HasSubstr("[bar='\\xff']")));
+  }
+}
+
+TEST(Status, AbslStringify) {
+  absl::Status status(absl::StatusCode::kInternal, "fail");
+  EXPECT_EQ("INTERNAL: fail", absl::StrCat(status));
+  EXPECT_EQ("INTERNAL: fail", absl::StrFormat("%v", status));
+  status.SetPayload("foo", absl::Cord("bar"));
+  EXPECT_EQ("INTERNAL: fail [foo='bar']", absl::StrCat(status));
+  status.SetPayload("bar", absl::Cord("\377"));
+  EXPECT_THAT(absl::StrCat(status),
+              AllOf(HasSubstr("INTERNAL: fail"), HasSubstr("[foo='bar']"),
+                    HasSubstr("[bar='\\xff']")));
+}
+
+TEST(Status, OstreamEqStringify) {
+  absl::Status status(absl::StatusCode::kUnknown, "fail");
+  status.SetPayload("foo", absl::Cord("bar"));
+  std::stringstream stream;
+  stream << status;
+  EXPECT_EQ(stream.str(), absl::StrCat(status));
+}
+
 absl::Status EraseAndReturn(const absl::Status& base) {
   absl::Status copy = base;
   EXPECT_TRUE(copy.ErasePayload(kUrl1));