Added bool argument

src/main/java/com/mojang/brigadier/arguments/BoolArgumentType.java

@@ -0,0 +1,46 @@
+package com.mojang.brigadier.arguments;
+
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.context.CommandContext;
+import com.mojang.brigadier.context.CommandContextBuilder;
+import com.mojang.brigadier.context.FixedParsedArgument;
+import com.mojang.brigadier.context.ParsedArgument;
+import com.mojang.brigadier.exceptions.CommandException;
+import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
+
+public class BoolArgumentType implements ArgumentType<Boolean> {
+    public static final SimpleCommandExceptionType ERROR_INVALID = new SimpleCommandExceptionType("argument.bool.invalid", "Value must be true or false");
+
+    private BoolArgumentType() {
+    }
+
+    public static BoolArgumentType bool() {
+        return new BoolArgumentType();
+    }
+
+    public static boolean getBool(CommandContext<?> context, String name) {
+        return context.getArgument(name, Boolean.class);
+    }
+
+    @Override
+    public <S> ParsedArgument<S, Boolean> parse(String command, CommandContextBuilder<S> contextBuilder) throws CommandException {
+        int end = command.indexOf(CommandDispatcher.ARGUMENT_SEPARATOR);
+        String raw = command;
+        if (end > -1) {
+            raw = command.substring(0, end);
+        }
+
+        if (raw.equals("true")) {
+            return new FixedParsedArgument<>(raw, true);
+        } else if (raw.equals("false")) {
+            return new FixedParsedArgument<>(raw, false);
+        } else {
+            throw ERROR_INVALID.create();
+        }
+    }
+
+    @Override
+    public String getUsageText() {
+        return "bool";
+    }
+}

src/test/java/com/mojang/brigadier/arguments/BoolArgumentTypeTest.java

@@ -0,0 +1,90 @@
+package com.mojang.brigadier.arguments;
+
+import com.mojang.brigadier.context.CommandContextBuilder;
+import com.mojang.brigadier.context.ParsedArgument;
+import com.mojang.brigadier.exceptions.CommandException;
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.util.Collections;
+
+import static com.mojang.brigadier.arguments.BoolArgumentType.ERROR_INVALID;
+import static com.mojang.brigadier.arguments.BoolArgumentType.bool;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.*;
+
+@RunWith(MockitoJUnitRunner.class)
+public class BoolArgumentTypeTest {
+    private BoolArgumentType type;
+    @Mock
+    private Object source;
+    @Mock
+    private CommandContextBuilder<Object> context;
+
+    @Before
+    public void setUp() throws Exception {
+        type = bool();
+    }
+
+    @Test
+    public void parse_true() throws Exception {
+        ParsedArgument<Object, Boolean> parse = type.parse("true", context);
+        assertThat(parse.getResult(source), is(true));
+        assertThat(parse.getRaw(), equalTo("true"));
+    }
+
+    @Test
+    public void parse_false() throws Exception {
+        ParsedArgument<Object, Boolean> parse = type.parse("false", context);
+        assertThat(parse.getResult(source), is(false));
+        assertThat(parse.getRaw(), equalTo("false"));
+    }
+
+    @Test
+    public void parse_trailing() throws Exception {
+        ParsedArgument<Object, Boolean> parse = type.parse("false hello world", context);
+        assertThat(parse.getResult(source), is(false));
+        assertThat(parse.getRaw(), equalTo("false"));
+    }
+
+    @Test
+    public void parse_invalid() throws Exception {
+        try {
+            type.parse("tuesday", context);
+        } catch (CommandException ex) {
+            assertThat(ex.getType(), is(ERROR_INVALID));
+            assertThat(ex.getData(), equalTo(Collections.emptyMap()));
+        }
+    }
+
+    @Test
+    public void parse_empty() throws Exception {
+        try {
+            type.parse("", context);
+        } catch (CommandException ex) {
+            assertThat(ex.getType(), is(ERROR_INVALID));
+            assertThat(ex.getData(), equalTo(Collections.emptyMap()));
+        }
+    }
+
+    @Test
+    public void parse_empty_remaining() throws Exception {
+        try {
+            type.parse(" true", context);
+        } catch (CommandException ex) {
+            assertThat(ex.getType(), is(ERROR_INVALID));
+            assertThat(ex.getData(), equalTo(Collections.emptyMap()));
+        }
+    }
+
+    @Test
+    public void usageText() throws Exception {
+        assertThat(type.getUsageText(), equalTo("bool"));
+    }
+}