fix(repl): fix multiline editing and completer navigation with keybindings

lib/node_modules/@stdlib/repl/lib/editor_actions.js

@@ -92,6 +92,9 @@ function EditorActions( repl, ttyWrite ) {
 	// Cache a reference to the REPL keybindings:
 	this._keybindings = repl._keybindings;
 
+	// Cache a reference to the multiline handler:
+	this._multilineHandler = repl._multilineHandler;
+
 	return this;
 }
 
@@ -170,6 +173,9 @@ setNonEnumerableReadOnly( EditorActions.prototype, '_modifyNextWord', function m
 * @returns {void}
 */
 setNonEnumerableReadOnly( EditorActions.prototype, 'moveRight', function moveRight() {
+	if ( this._multilineHandler && this._multilineHandler.moveRight() ) {
+		return;
+	}
 	this._ttyWrite.call( this._rli, null, {
 		'name': 'right'
 	});
@@ -184,6 +190,9 @@ setNonEnumerableReadOnly( EditorActions.prototype, 'moveRight', function moveRig
 * @returns {void}
 */
 setNonEnumerableReadOnly( EditorActions.prototype, 'moveLeft', function moveLeft() {
+	if ( this._multilineHandler && this._multilineHandler.moveLeft() ) {
+		return;
+	}
 	this._ttyWrite.call( this._rli, null, {
 		'name': 'left'
 	});
@@ -308,6 +317,9 @@ setNonEnumerableReadOnly( EditorActions.prototype, 'indentLineLeft', function in
 * @returns {void}
 */
 setNonEnumerableReadOnly( EditorActions.prototype, 'deleteLeft', function deleteLeft() {
+	if ( this._multilineHandler && this._multilineHandler.deleteLeft() ) {
+		return;
+	}
 	this._ttyWrite.call( this._rli, null, {
 		'name': 'backspace'
 	});

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

@@ -380,8 +380,6 @@ function REPL( options ) {
 		}
 		self._autoCloser.beforeKeypress( data, key );
 		completed = self._previewCompleter.beforeKeypress( data, key );
-		FLG = self._editorActions.beforeKeypress( data, key );
-		self._eagerEvaluator.beforeKeypress( data, key );
 
 		// If ENTER keypress is encountered or if a preview was completed while navigating, gracefully close the completer...
 		if ( completed || ( key && key.name === 'return' ) ) {
@@ -390,6 +388,8 @@ function REPL( options ) {
 			self._completerEngine.beforeKeypress( data, key );
 			return;
 		}
+		FLG = self._editorActions.beforeKeypress( data, key );
+		self._eagerEvaluator.beforeKeypress( data, key );
 		// If completion was auto-completed or an action was triggered, don't trigger multi-line keybindings to avoid double operations...
 		if ( !completed && !FLG ) {
 			self._multilineHandler.beforeKeypress( data, key );

lib/node_modules/@stdlib/repl/lib/multiline_handler.js

@@ -714,6 +714,78 @@ setNonEnumerableReadOnly( MultilineHandler.prototype, 'onKeypress', function onK
 	}
 });
 
+/**
+* Moves the cursor to the previous line if at the beginning of the current line in multi-line mode.
+*
+* @name moveLeft
+* @memberof MultilineHandler.prototype
+* @type {Function}
+* @returns {boolean} boolean indicating whether the cursor moved to the previous line
+*/
+setNonEnumerableReadOnly( MultilineHandler.prototype, 'moveLeft', function moveLeft() {
+	if ( this._history.index !== 0 ) {
+		// Reset current history cycle:
+		this._resetHistoryBuffers();
+	}
+	// If at the beginning of the line, move up to the previous line:
+	if ( this._rli.cursor === 0 && this._lineIndex > 0 ) {
+		this._moveLeft();
+		if ( this._multiline.active ) {
+			this._renderLines();
+		}
+		return true;
+	}
+	return false;
+});
+
+/**
+* Moves the cursor to the next line if at the end of the current line in multi-line mode.
+*
+* @name moveRight
+* @memberof MultilineHandler.prototype
+* @type {Function}
+* @returns {boolean} boolean indicating whether the cursor moved to the next line
+*/
+setNonEnumerableReadOnly( MultilineHandler.prototype, 'moveRight', function moveRight() {
+	if ( this._history.index !== 0 ) {
+		// Reset current history cycle:
+		this._resetHistoryBuffers();
+	}
+	// If at the end of the line, move to the next line:
+	if ( this._rli.cursor === this._rli.line.length && this._lineIndex < this._lines.length - 1 ) {
+		this._moveRight();
+		if ( this._multiline.active ) {
+			this._renderLines();
+		}
+		return true;
+	}
+	return false;
+});
+
+/**
+* Simulates a backspace across line boundaries if at the beginning of the current line in multi-line mode.
+*
+* @name deleteLeft
+* @memberof MultilineHandler.prototype
+* @type {Function}
+* @returns {boolean} boolean indicating whether the current line was removed and merged into the previous line
+*/
+setNonEnumerableReadOnly( MultilineHandler.prototype, 'deleteLeft', function deleteLeft() {
+	if ( this._history.index !== 0 ) {
+		// Reset current history cycle:
+		this._resetHistoryBuffers();
+	}
+	// If at the beginning of the line, remove and move up to the previous line:
+	if ( this._rli.cursor === 0 && this._lineIndex > 0 ) {
+		this._backspace();
+		if ( this._multiline.active ) {
+			this._renderLines();
+		}
+		return true;
+	}
+	return false;
+});
+
 /**
 * Callback which should be invoked **before** a "keypress" event is processed by a readline interface.
 *
@@ -766,46 +838,19 @@ setNonEnumerableReadOnly( MultilineHandler.prototype, 'beforeKeypress', function
 		}
 		break;
 	case 'left':
-		if ( this._history.index !== 0 ) {
-			// Reset current history cycle:
-			this._resetHistoryBuffers();
-		}
-		// If at the beginning of the line, move up to the previous line; otherwise, trigger default behavior...
-		if ( this._rli.cursor === 0 ) {
-			this._moveLeft();
-			if ( this._multiline.active ) {
-				this._renderLines();
-			}
+		if ( this.moveLeft() ) {
 			return;
 		}
 		this._ttyWrite.call( this._rli, data, key );
 		break;
 	case 'right':
-		if ( this._history.index !== 0 ) {
-			// Reset current history cycle:
-			this._resetHistoryBuffers();
-		}
-		// If at the end of the line, move up to the next line; otherwise, trigger default behavior...
-		if ( this._rli.cursor === this._rli.line.length ) {
-			this._moveRight();
-			if ( this._multiline.active ) {
-				this._renderLines();
-			}
+		if ( this.moveRight() ) {
 			return;
 		}
 		this._ttyWrite.call( this._rli, data, key );
 		break;
 	case 'backspace':
-		if ( this._history.index !== 0 ) {
-			// Reset current history cycle:
-			this._resetHistoryBuffers();
-		}
-		// If at the beginning of the line, remove and move up to the previous line; otherwise, trigger default behavior...
-		if ( this._rli.cursor === 0 ) {
-			this._backspace();
-			if ( this._multiline.active ) {
-				this._renderLines();
-			}
+		if ( this.deleteLeft() ) {
 			return;
 		}
 		this._ttyWrite.call( this._rli, data, key );