Add builders to APDU command class

device/u2f/u2f_apdu_unittest.cc

Index: device/u2f/u2f_apdu_unittest.cc
diff --git a/device/u2f/u2f_apdu_unittest.cc b/device/u2f/u2f_apdu_unittest.cc
index a0435eb0d97ef560663e540fb9fd0d7262d97986..0526b2f55ba9439ee52c76ec949a42b45bd3bd7b 100644
--- a/device/u2f/u2f_apdu_unittest.cc
+++ b/device/u2f/u2f_apdu_unittest.cc
@@ -181,4 +181,31 @@ TEST_F(U2fApduTest, TestSerializeEdgeCases) {
                   U2fApduCommand::CreateFromMessage(cmd->GetEncodedCommand())
                       ->GetEncodedCommand()));
 }
+
+TEST_F(U2fApduTest, TestBuildApdu) {

[juanlang (chromium.org), 2017/01/28 00:08:39]

BuildGetVersionCommand and BuildGetLegacyVersionCommand need tests too, please.

[Reilly Grant (use Gerrit), 2017/01/28 00:29:29]

Put each one in its own test method.

[Casey Piper, 2017/01/30 21:51:41]

Done.

[Casey Piper, 2017/01/30 21:51:41]

Done.

+  std::vector<uint8_t> appid(U2fApduCommand::kAppIdDigestLen, 0x01);
+  std::vector<uint8_t> challenge(U2fApduCommand::kChallengeDigestLen, 0xff);
+  scoped_refptr<U2fApduCommand> cmd =
+      U2fApduCommand::BuildRegisterCommand(appid, challenge);
+  ASSERT_NE(nullptr, cmd);
+  EXPECT_THAT(U2fApduCommand::CreateFromMessage(cmd->GetEncodedCommand())
+                  ->GetEncodedCommand(),
+              testing::ContainerEq(cmd->GetEncodedCommand()));
+  // Expect null result with appid.size() > kAppIdDigestLen
+  appid.push_back(0xff);
+  cmd = U2fApduCommand::BuildRegisterCommand(appid, challenge);
+  EXPECT_EQ(nullptr, cmd);
+
+  appid.pop_back();
+  std::vector<uint8_t> key_handle(U2fApduCommand::kMaxKeyHandleLength);
+  cmd = U2fApduCommand::BuildSignCommand(appid, challenge, key_handle);
+  ASSERT_NE(nullptr, cmd);
+  EXPECT_THAT(U2fApduCommand::CreateFromMessage(cmd->GetEncodedCommand())
+                  ->GetEncodedCommand(),
+              testing::ContainerEq(cmd->GetEncodedCommand()));
+  // Expect null result with appid.size() > kMaxKeyHandleLength
+  key_handle.push_back(0x0f);
+  cmd = U2fApduCommand::BuildSignCommand(appid, challenge, key_handle);
+  EXPECT_EQ(nullptr, cmd);
+}
 }  // namespace device