network_diagnostics: Expand util functions

Add new util functions needed by HttpsLatency routine.

BUG=chromium:956783
TEST=unit_tests --gtest_filter=NetworkDiagnosticsUtilTest*

Change-Id: Ieae113b0df25f6b55658d701fd4b39b81948bd91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2442329
Commit-Queue: Kartik Hegde <khegde@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812891}

chrome/browser/chromeos/net/network_diagnostics/network_diagnostics_util.cc

@@ -18,6 +18,8 @@ namespace network_diagnostics {
 
 namespace util {
 
+const char kGenerate204Path[] = "/generate_204";
+
 namespace {
 
 // Returns |num_prefixes| prefixes of size |length|, where no two entries are
@@ -78,6 +80,27 @@ std::vector<std::string> GetRandomHostsWithFixedHosts(int num_random_hosts,
   return hosts;
 }
 
+std::vector<std::string> GetRandomHostsWithScheme(int num_hosts,
+                                                  int prefix_length,
+                                                  std::string scheme) {
+  std::vector<std::string> hosts = GetRandomHosts(num_hosts, prefix_length);
+  for (auto& host : hosts) {
+    host = scheme + host;
+  }
+  return hosts;
+}
+
+std::vector<std::string> GetRandomHostsWithSchemeAndGenerate204Path(
+    int num_hosts,
+    int prefix_length,
+    std::string scheme) {
+  std::vector<std::string> hosts = GetRandomHosts(num_hosts, prefix_length);
+  for (auto& host : hosts) {
+    host = scheme + host + kGenerate204Path;
+  }
+  return hosts;
+}
+
 Profile* GetUserProfile() {
   return ProfileManager::GetPrimaryUserProfile();
 }

chrome/browser/chromeos/net/network_diagnostics/network_diagnostics_util.h

@@ -15,6 +15,9 @@ namespace network_diagnostics {
 
 namespace util {
 
+// Generate 204 path.
+extern const char kGenerate204Path[];
+
 // Returns the Gstatic host suffix. Network diagnostic routines attach a random
 // prefix to |kGstaticHostSuffix| to get a complete hostname.
 const char* GetGstaticHostSuffix();
@@ -35,6 +38,17 @@ std::vector<std::string> GetRandomHosts(int num_hosts, int prefix_length);
 std::vector<std::string> GetRandomHostsWithFixedHosts(int num_random_hosts,
                                                       int prefix_length);
 
+// Similar to GetRandomHosts, but with a |scheme| prepended to the hosts.
+std::vector<std::string> GetRandomHostsWithScheme(int num_hosts,
+                                                  int prefix_length,
+                                                  std::string scheme);
+
+// Similar to GetRandomHostsWithScheme, but with the 204 path appended to hosts.
+std::vector<std::string> GetRandomHostsWithSchemeAndGenerate204Path(
+    int num_hosts,
+    int prefix_length,
+    std::string scheme);
+
 // Returns the profile associated with this account.
 Profile* GetUserProfile();
 

chrome/browser/chromeos/net/network_diagnostics/network_diagnostics_util_unittest.cc

@@ -7,19 +7,26 @@
 #include <string>
 #include <vector>
 
+#include "base/strings/string_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace chromeos {
 namespace network_diagnostics {
 
+namespace {
+
+const char kHttpsScheme[] = "https://";
+
+}  // namespace
+
 TEST(NetworkDiagnosticsUtilTest, TestGetRandomString) {
   int length = 8;
   auto random_string = util::GetRandomString(length);
   // Ensure that the length equals |length| and all characters are in between
   // 'a'-'z', inclusive.
-  ASSERT_EQ(length, random_string.size());
+  EXPECT_EQ(length, random_string.size());
   for (char const& c : random_string) {
-    ASSERT_TRUE(c >= 'a' && c <= 'z');
+    EXPECT_TRUE(c >= 'a' && c <= 'z');
   }
 }
 
@@ -30,8 +37,43 @@ TEST(NetworkDiagnosticsUtilTest, TestGetRandomHosts) {
       util::GetRandomHosts(num_hosts, prefix_length);
   // Ensure |random_hosts| has unique entries.
   std::sort(random_hosts.begin(), random_hosts.end());
-  ASSERT_TRUE(std::adjacent_find(random_hosts.begin(), random_hosts.end()) ==
+  EXPECT_TRUE(std::adjacent_find(random_hosts.begin(), random_hosts.end()) ==
+              random_hosts.end());
+}
+
+TEST(NetworkDiagnosticsUtilTest, TestGetRandomHostsWithScheme) {
+  int num_hosts = 10;
+  int prefix_length = 8;
+  std::vector<std::string> random_hosts =
+      util::GetRandomHostsWithScheme(num_hosts, prefix_length, kHttpsScheme);
+  // Ensure |random_hosts| has unique entries.
+  std::sort(random_hosts.begin(), random_hosts.end());
+  EXPECT_TRUE(std::adjacent_find(random_hosts.begin(), random_hosts.end()) ==
               random_hosts.end());
+  // Ensure hosts in |random_hosts| start with |kHttpsScheme|.
+  for (const auto& host : random_hosts) {
+    EXPECT_TRUE(host.rfind(kHttpsScheme, 0) == 0);
+  }
+}
+
+TEST(NetworkDiagnosticsUtilTest,
+     TestGetRandomHostsWithSchemeAndGenerate204Path) {
+  int num_hosts = 10;
+  int prefix_length = 8;
+  std::vector<std::string> random_hosts =
+      util::GetRandomHostsWithSchemeAndGenerate204Path(num_hosts, prefix_length,
+                                                       kHttpsScheme);
+  // Ensure |random_hosts| has unique entries.
+  std::sort(random_hosts.begin(), random_hosts.end());
+  EXPECT_TRUE(std::adjacent_find(random_hosts.begin(), random_hosts.end()) ==
+              random_hosts.end());
+  // Ensure:
+  // (1) hosts in |random_hosts| start with |kHttpsScheme|.
+  // (2) hosts in |random_hosts| end with |kGenerate204Path|.
+  for (const auto& host : random_hosts) {
+    EXPECT_TRUE(host.rfind(kHttpsScheme, 0) == 0);
+    EXPECT_TRUE(base::EndsWith(host, util::kGenerate204Path));
+  }
 }
 
 }  // namespace network_diagnostics