function onCommand( fpath ) {
		var err;
		if ( !isString( fpath ) ) {
			err = new TypeError( format( 'invalid argument. Must provide a string. Value: `%s`.', fpath ) );
			debug( 'Error: %s', err.message );
			repl._ostream.write( 'Error: '+err.message+'\n' );
			return;
		}
		repl.once( 'drain', onDrain );

		/**
		* Callback invoked upon a 'drain' event.
		*
		* @private
		*/
		function onDrain() {
			debug( 'Loading a file...' );
			repl.load( fpath, clbk );
		}

		/**
		* Callback invoked upon loading a file.
		*
		* @private
		* @param {Error} [error] - error object
		*/
		function clbk( error ) {
			var pos;
			if ( error ) {
				// NOTE: we can assume that the error pertains to actually reading the file (e.g., loading from disk) and NOT the line-by-line evaluation, where error handling should be handled separately...
				debug( 'Error: %s', error.message );

				// Infer the current cursor column position based on the length of the command prompt string:
				pos = repl._prompt().length; // FIXME: how to address multi-column characters?

				// FIXME: handle non-TTY output streams!

				/*
				* Print the error message on the previous line and generate the expected display prompt and cursor position.
				*
				* [ANSI escape sequences][1]:
				*
				* -   `\u001b`: ESC, the escape character
				* -   `[1A`: move cursor up one line
				* -   `[nD`: move cursor back (to the left) `n` columns (cells)
				* -   `[0J`: clear the screen beginning from the current cursor position to the end of the screen
				*
				* [1]: https://en.wikipedia.org/wiki/ANSI_escape_code
				*/
				repl._ostream.write( '\u001b[1A\u001b['+pos+'DError: '+error.message+'\u001b[0J\n' );

				// Show a new display prompt:
				repl._displayPrompt();
				return;
			}
			debug( 'Successfully loaded file.' );
		}
	}
Loads and evaluates a JavaScript file line-by-line.

@private
@param {string} fpath - file path
@returns {void}