Fix bug causing process to hang upon quitting a REPL

Author: kgryte

lib/node_modules/@stdlib/repl/presentation/bin/cli

@@ -24,7 +24,8 @@
 
 var resolve = require( 'path' ).resolve;
 var ReadStream = require( 'tty' ).ReadStream;
-var open = require( '@stdlib/fs/open' ); // eslint-disable-line stdlib/no-redeclare
+var openSync = require( '@stdlib/fs/open' ).sync;
+var closeSync = require( '@stdlib/fs/close' ).sync;
 var readFileSync = require( '@stdlib/fs/read-file' ).sync;
 var CLI = require( '@stdlib/tools/cli' );
 var stdin = require( '@stdlib/process/read-stdin' );
@@ -176,30 +177,35 @@ function main() {
 	* @returns {void}
 	*/
 	function onRead( error, text ) {
+		var repl;
+		var pres;
+		var fd;
 		if ( error ) {
 			return cli.error( error );
 		}
 		// Because we received input over `stdin`, we need to create a new TTY `stdin` read stream for receiving interactive user input...
-		open( '/dev/tty', 'r', onOpen );
+		fd = openSync( '/dev/tty', 'r' );
+		if ( fd instanceof Error ) {
+			return cli.error( error );
+		}
+		opts1.input = new ReadStream( fd ); // note: instance of net.Socket
+
+		// Create a new REPL instance:
+		repl = new REPL( opts1 );
+		repl.once( 'exit', onExit );
+
+		// Create a new REPL presentation:
+		pres = new Presentation( text.toString(), repl, opts2 );
+		pres.show();
 
 		/**
-		* Callback invoked upon opening a file.
+		* Callback invoked upon exiting a REPL.
 		*
 		* @private
-		* @param {(Error|null)} error - error object
-		* @param {integer} fd - file descriptor
-		* @returns {void}
 		*/
-		function onOpen( error, fd ) {
-			var repl;
-			var pres;
-			if ( error ) {
-				return cli.error( error );
-			}
-			opts1.input = new ReadStream( fd );
-			repl = new REPL( opts1 );
-			pres = new Presentation( text.toString(), repl, opts2 );
-			pres.show();
+		function onExit() {
+			opts1.input.end(); // close socket to prevent the process from hanging (see https://github.com/nodejs/node-v0.x-archive/issues/7101)
+			closeSync( fd );
 		}
 	}
 }