Fix async code handling

Author: kgryte

lib/node_modules/@stdlib/repl/presentation/lib/main.js

@@ -23,6 +23,7 @@
 // MODULES //
 
 var logger = require( 'debug' );
+var isFunction = require( '@stdlib/assert/is-function' );
 var setNonEnumerableReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
 var setNonEnumerableReadOnlyAccessor = require( '@stdlib/utils/define-nonenumerable-read-only-accessor' ); // eslint-disable-line id-length
 var setNonEnumerable = require( '@stdlib/utils/define-nonenumerable-property' );
@@ -395,24 +396,55 @@ setNonEnumerableReadOnly( Presentation.prototype, 'lastFragment', function lastF
 * @name run
 * @memberof Presentation.prototype
 * @type {Function}
-* @returns {Presentation} presentation instance
+* @param {Function} clbk - callback
+* @throws {TypeError} must provide a function
+* @returns {void}
 *
 * @example
 * // TODO
 */
-setNonEnumerableReadOnly( Presentation.prototype, 'run', function run() {
+setNonEnumerableReadOnly( Presentation.prototype, 'run', function run( clbk ) {
+	var self;
 	var code;
+	var len;
 	var i;
 
+	if ( !isFunction( clbk ) ) {
+		throw new TypeError( 'invalid argument. Must provide a function. Value: `' + clbk + '`.' );
+	}
+	self = this;
 	code = this._slides[ this._slideCursor ].code;
 	if ( code && code.length ) {
 		// Forward each line of code to the REPL readline interface in order to mimic user input...
-		for ( i = 0; i < code.length; i++ ) {
-			this._repl._rli.write( code[ i ]+'\n' );
-			this._repl._displayPrompt( false );
+		len = code.length;
+		i = -1;
+		return next();
+	}
+	// TODO: replace with polyfill
+	process.nextTick( clbk );
+
+	/**
+	* Callback invoked the REPL command queue drains.
+	*
+	* @private
+	* @param {string} cmd - command
+	* @param {boolean} success - boolean indicating whether the command successfully executed
+	*/
+	function next() {
+		i += 1;
+		if ( i < len ) {
+			if ( code[ i ] ) {
+				self._repl._rli.write( code[ i ]+'\n' );
+				self._repl.once( 'drain', next );
+			} else {
+				// TODO: replace with polyfill
+				process.nextTick( next );
+			}
+		} else {
+			// TODO: replace with polyfill
+			process.nextTick( clbk );
 		}
 	}
-	return this;
 });
 
 /**