Add better tests for the -h and -help accepted values.

It looks like this test was intended to add coverage for these option-like values that we accept as commands, but it did not actually test this.

RELNOTES: None.
PiperOrigin-RevId: 201380534

src/test/cpp/option_processor_test.cc

diff --git a/src/test/cpp/option_processor_test.cc b/src/test/cpp/option_processor_test.cc
index d963fbb..6048b80 100644
--- a/src/test/cpp/option_processor_test.cc
+++ b/src/test/cpp/option_processor_test.cc
@@ -78,6 +78,19 @@
     EXPECT_EQ(expected.command_args, result->command_args);
   }
 
+  void HelpArgIsInterpretedAsACommand(const std::string& arg) {
+    const std::vector<std::string> args = {"bazel", arg};
+    std::string error;
+    ASSERT_EQ(blaze_exit_code::SUCCESS,
+              option_processor_->ParseOptions(args, workspace_, cwd_, &error))
+        << error;
+    ASSERT_EQ("", error);
+
+    EXPECT_EQ(arg, option_processor_->GetCommand());
+    EXPECT_EQ(std::vector<std::string>({}),
+              option_processor_->GetExplicitCommandArguments());
+  }
+
   const std::string workspace_;
   const std::string cwd_;
   const std::unique_ptr<WorkspaceLayout> workspace_layout_;
@@ -108,7 +121,7 @@
             option_processor_->GetExplicitCommandArguments());
 }
 
-TEST_F(OptionProcessorTest, CanParseHelpArgs) {
+TEST_F(OptionProcessorTest, CanParseHelpCommandSurroundedByOtherArgs) {
   const std::vector<std::string> args =
       {"bazel",
        "--host_jvm_args=MyParam", "--nobatch",
@@ -132,6 +145,18 @@
             option_processor_->GetExplicitCommandArguments());
 }
 
+TEST_F(OptionProcessorTest, CanParseHelpCommand) {
+  HelpArgIsInterpretedAsACommand("help");
+}
+
+TEST_F(OptionProcessorTest, CanParseHelpShortFlag) {
+  HelpArgIsInterpretedAsACommand("-h");
+}
+
+TEST_F(OptionProcessorTest, CanParseHelpFlag) {
+  HelpArgIsInterpretedAsACommand("-help");
+}
+
 TEST_F(OptionProcessorTest, CanParseEmptyArgs) {
   const std::vector<std::string> args = {"bazel"};
   std::string error;