implement FileExists BIF and tests

src/main/java/ortus/boxlang/runtime/bifs/global/io/FileExists.java

@@ -0,0 +1,52 @@
+
+package ortus.boxlang.runtime.bifs.global.io;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import ortus.boxlang.runtime.bifs.BIF;
+import ortus.boxlang.runtime.bifs.BoxBIF;
+import ortus.boxlang.runtime.context.IBoxContext;
+import ortus.boxlang.runtime.scopes.ArgumentsScope;
+import ortus.boxlang.runtime.scopes.Key;
+import ortus.boxlang.runtime.types.Argument;
+import ortus.boxlang.runtime.types.exceptions.BoxRuntimeException;
+import ortus.boxlang.runtime.util.FileSystemUtil;
+
+@BoxBIF
+
+public class FileExists extends BIF {
+
+	/**
+	 * Constructor
+	 */
+	public FileExists() {
+		super();
+		declaredArguments = new Argument[] {
+		    new Argument( true, "string", Key.source ),
+		    new Argument( true, "boolean", Key.allowRealPath, true )
+		};
+	}
+
+	/**
+	 * Describe what the invocation of your bif function does
+	 *
+	 * @param context   The context in which the BIF is being invoked.
+	 * @param arguments Argument scope for the BIF.
+	 *
+	 * @argument.foo Describe any expected arguments
+	 */
+	public Object invoke( IBoxContext context, ArgumentsScope arguments ) {
+		String	filePath		= arguments.getAsString( Key.source );
+		Boolean	allowRealPath	= arguments.getAsBoolean( Key.allowRealPath );
+
+		if ( !allowRealPath && Path.of( filePath ).isAbsolute() ) {
+			throw new BoxRuntimeException(
+			    "The file or path argument [" + filePath + "] is an absolute path. This is disallowed when the allowRealPath argument is set to false."
+			);
+		}
+
+		return ( Boolean ) FileSystemUtil.exists( filePath ) && !Files.isDirectory( Path.of( filePath ) );
+	}
+
+}

src/main/java/ortus/boxlang/runtime/scopes/Key.java

@@ -94,6 +94,8 @@ public class Key {
 	public static final Key	charset				= Key.of( "charset" );
 	public static final Key	buffersize			= Key.of( "buffersize" );
 	public static final Key	charsetOrBufferSize	= Key.of( "charsetOrBufferSize" );
+	public static final Key	source				= Key.of( "source" );
+	public static final Key	allowRealPath		= Key.of( "allowRealPath" );
 
 	// DateTime Common Argument Keys
 	public static final Key	date				= Key.of( "date" );

src/test/java/ortus/boxlang/runtime/bifs/global/io/FileExistsTest.java

@@ -0,0 +1,110 @@
+
+/**
+ * [BoxLang]
+ *
+ * Copyright [2023] [Ortus Solutions, Corp]
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ortus.boxlang.runtime.bifs.global.io;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.IOException;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import ortus.boxlang.runtime.BoxRuntime;
+import ortus.boxlang.runtime.context.IBoxContext;
+import ortus.boxlang.runtime.context.ScriptingBoxContext;
+import ortus.boxlang.runtime.scopes.IScope;
+import ortus.boxlang.runtime.scopes.Key;
+import ortus.boxlang.runtime.scopes.VariablesScope;
+import ortus.boxlang.runtime.util.FileSystemUtil;
+
+public class FileExistsTest {
+
+	static BoxRuntime	instance;
+	static IBoxContext	context;
+	static IScope		variables;
+	static Key			result	= new Key( "result" );
+
+	@BeforeAll
+	public static void setUp() {
+		instance	= BoxRuntime.getInstance( true );
+		context		= new ScriptingBoxContext( instance.getRuntimeContext() );
+		variables	= context.getScopeNearby( VariablesScope.name );
+	}
+
+	@AfterAll
+	public static void teardown() {
+		instance.shutdown();
+	}
+
+	@BeforeEach
+	public void setupEach() {
+		variables.clear();
+	}
+
+	@DisplayName( "It tests the BIF FileExists on an existing file" )
+	@Test
+	public void testFileExists() throws IOException {
+		String testFile = "src/test/resources/tmp/exists.txt";
+		variables.put( Key.of( "testFile" ), Path.of( testFile ).toAbsolutePath().toString() );
+		FileSystemUtil.write( testFile, "file exists test!".getBytes( "UTF-8" ), true );
+		assertTrue( FileSystemUtil.exists( testFile ) );
+		instance.executeSource(
+		    """
+		    result = fileExists( variables.testFile );
+		    """,
+		    context );
+		Boolean result = ( Boolean ) variables.get( Key.of( "result" ) );
+		assertTrue( result );
+	}
+
+	@DisplayName( "It tests the BIF FileExists on a non-existent file" )
+	@Test
+	public void testFileNotExists() throws IOException {
+		String testFile = "src/test/resources/tmp/not-exists.txt";
+		variables.put( Key.of( "testFile" ), Path.of( testFile ).toAbsolutePath().toString() );
+		instance.executeSource(
+		    """
+		    result = fileExists( variables.testFile );
+		    """,
+		    context );
+		Boolean result = ( Boolean ) variables.get( Key.of( "result" ) );
+		assertFalse( result );
+	}
+
+	@DisplayName( "It tests the BIF FileExists on a directory" )
+	@Test
+	public void testDirectoryNotExists() throws IOException {
+		String testFile = "src/test/resources/tmp";
+		variables.put( Key.of( "testFile" ), Path.of( testFile ).toAbsolutePath().toString() );
+		instance.executeSource(
+		    """
+		    result = fileExists( variables.testFile );
+		    """,
+		    context );
+		Boolean result = ( Boolean ) variables.get( Key.of( "result" ) );
+		assertFalse( result );
+	}
+
+}