Add Candidate::type_name()

Candidate::type() is currently how the name of the type is fetched,
but that getter returns a non-standard type name.

Instead, I'm adding a new getter, type_name(), will follow up with
updating dependent code that needs the string, to use type_name (and
adapt to potential dependency on "local" or "stun") and then switch
type() to be enum based.

Also adding a test file for Candidate with a couple of basic tests to
start with.

Bug: webrtc:15846
Change-Id: I9b78b2405a9f962a3c07eaa8e72a79854c6f5ceb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/339660
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41740}

api/BUILD.gn

@@ -1430,6 +1430,7 @@ if (rtc_include_tests) {
 
     sources = [
       "array_view_unittest.cc",
+      "candidate_unittest.cc",
       "field_trials_unittest.cc",
       "function_view_unittest.cc",
       "rtc_error_unittest.cc",
@@ -1445,6 +1446,7 @@ if (rtc_include_tests) {
 
     deps = [
       ":array_view",
+      ":candidate",
       ":create_time_controller",
       ":field_trials",
       ":field_trials_view",
@@ -1458,12 +1460,14 @@ if (rtc_include_tests) {
       ":scoped_refptr",
       ":sequence_checker",
       ":time_controller",
+      "../p2p:rtc_p2p",
       "../rtc_base:buffer",
       "../rtc_base:checks",
       "../rtc_base:gunit_helpers",
       "../rtc_base:platform_thread",
       "../rtc_base:rtc_event",
       "../rtc_base:rtc_task_queue",
+      "../rtc_base:ssl",
       "../rtc_base:task_queue_for_test",
       "../rtc_base/containers:flat_set",
       "../rtc_base/task_utils:repeating_task",

api/candidate.cc

@@ -27,6 +27,7 @@ Candidate::Candidate()
     : id_(rtc::CreateRandomString(8)),
       component_(0),
       priority_(0),
+      type_(LOCAL_PORT_TYPE),
       network_type_(rtc::ADAPTER_TYPE_UNKNOWN),
       underlying_type_for_vpn_(rtc::ADAPTER_TYPE_UNKNOWN),
       generation_(0),
@@ -76,6 +77,17 @@ bool Candidate::is_relay() const {
   return type_ == RELAY_PORT_TYPE;
 }
 
+absl::string_view Candidate::type_name() const {
+  // The LOCAL_PORT_TYPE and STUN_PORT_TYPE constants are not the standard type
+  // names, so check for those specifically. For other types, `type_` will have
+  // the correct name.
+  if (is_local())
+    return "host";
+  if (is_stun())
+    return "srflx";
+  return type_;
+}
+
 bool Candidate::IsEquivalent(const Candidate& c) const {
   // We ignore the network name, since that is just debug information, and
   // the priority and the network cost, since they should be the same if the

api/candidate.h

@@ -93,6 +93,10 @@ class RTC_EXPORT Candidate {
 
   const std::string& type() const { return type_; }
 
+  // Returns the name of the candidate type as specified in
+  // https://datatracker.ietf.org/doc/html/rfc5245#section-15.1
+  absl::string_view type_name() const;
+
   // Setting the type requires a constant string (e.g.
   // cricket::LOCAL_PORT_TYPE). The type should really be an enum rather than a
   // string, but until we make that change the lifetime attribute helps us lock

api/candidate_unittest.cc

@@ -0,0 +1,54 @@
+/*
+ *  Copyright 2024 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 "api/candidate.h"
+
+#include <string>
+
+#include "p2p/base/p2p_constants.h"
+#include "rtc_base/gunit.h"
+
+namespace cricket {
+
+TEST(CandidateTest, Id) {
+  Candidate c;
+  EXPECT_EQ(c.id().size(), 8u);
+  std::string new_id = "12345678";
+  c.set_id(new_id);
+  EXPECT_EQ(new_id, c.id());
+}
+
+TEST(CandidateTest, Component) {
+  Candidate c;
+  EXPECT_EQ(c.component(), 0);
+  c.set_component(ICE_CANDIDATE_COMPONENT_DEFAULT);
+  EXPECT_EQ(c.component(), ICE_CANDIDATE_COMPONENT_DEFAULT);
+}
+
+TEST(CandidateTest, TypeName) {
+  Candidate c;
+  // The `type_name()` property defaults to "host".
+  EXPECT_EQ(c.type_name(), "host");
+  EXPECT_EQ(c.type(), LOCAL_PORT_TYPE);
+
+  c.set_type(STUN_PORT_TYPE);
+  EXPECT_EQ(c.type_name(), "srflx");
+  EXPECT_EQ(c.type(), STUN_PORT_TYPE);
+
+  c.set_type(PRFLX_PORT_TYPE);
+  EXPECT_EQ(c.type_name(), "prflx");
+  EXPECT_EQ(c.type(), PRFLX_PORT_TYPE);
+
+  c.set_type(RELAY_PORT_TYPE);
+  EXPECT_EQ(c.type_name(), "relay");
+  EXPECT_EQ(c.type(), RELAY_PORT_TYPE);
+}
+
+}  // namespace cricket