Merge pull request #289 from ckeditor/t/ckeditor5-watchdog/1

Other: Added context as second required argument to the `CKEditorError`'s constructor, changed `isCKEditorError()` method to `is()`. Introduced the `areConnectedThroughProperties()` utility Part of the ckeditor/ckeditor5-watchdog#1.

src/areconnectedthroughproperties.js

@@ -0,0 +1,92 @@
+/**
+ * @license Copyright (c) 2003-2019, CKSource - Frederico Knabben. All rights reserved.
+ * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
+ */
+
+/**
+ * @module utils/arestructuresconnected
+ */
+
+/* globals EventTarget, Event */
+
+/**
+ * Traverses both structures to find out whether there is a reference that is shared between both structures.
+ *
+ * @param {Object|Array} obj1
+ * @param {Object|Array} obj2
+ */
+export default function areConnectedThroughProperties( obj1, obj2 ) {
+	if ( obj1 === obj2 && isObject( obj1 ) ) {
+		return true;
+	}
+
+	const subNodes1 = getSubNodes( obj1 );
+	const subNodes2 = getSubNodes( obj2 );
+
+	for ( const node of subNodes1 ) {
+		if ( subNodes2.has( node ) ) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+// Traverses JS structure and stores all sub-nodes, including the head node.
+// It walks into each iterable structures with the `try catch` block to omit errors that might be thrown during
+// tree walking. All primitives, functions and built-ins are skipped.
+function getSubNodes( head ) {
+	const nodes = [ head ];
+
+	// Nodes are stored to prevent infinite looping.
+	const subNodes = new Set();
+
+	while ( nodes.length > 0 ) {
+		const node = nodes.shift();
+
+		if ( subNodes.has( node ) || shouldNodeBeSkipped( node ) ) {
+			continue;
+		}
+
+		subNodes.add( node );
+
+		// Handle arrays, maps, sets, custom collections that implements `[ Symbol.iterator ]()`, etc.
+		if ( node[ Symbol.iterator ] ) {
+			// The custom editor iterators might cause some problems if the editor is crashed.
+			try {
+				nodes.push( ...node );
+			} catch ( err ) {
+				// eslint-disable-line no-empty
+			}
+		} else {
+			nodes.push( ...Object.values( node ) );
+		}
+	}
+
+	return subNodes;
+}
+
+function shouldNodeBeSkipped( node ) {
+	const type = Object.prototype.toString.call( node );
+
+	return (
+		type === '[object Number]' ||
+		type === '[object Boolean]' ||
+		type === '[object String]' ||
+		type === '[object Symbol]' ||
+		type === '[object Function]' ||
+		type === '[object Date]' ||
+		type === '[object RegExp]' ||
+
+		node === undefined ||
+		node === null ||
+
+		// Skip native DOM objects, e.g. Window, nodes, events, etc.
+		node instanceof EventTarget ||
+		node instanceof Event
+	);
+}
+
+function isObject( structure ) {
+	return typeof structure === 'object' && structure !== null;
+}

src/ckeditorerror.js

@@ -32,11 +32,16 @@ export default class CKEditorError extends Error {
 	 * @param {String} message The error message in an `error-name: Error message.` format.
 	 * During the minification process the "Error message" part will be removed to limit the code size
 	 * and a link to this error documentation will be added to the `message`.
+	 * @param {Object|null} context A context of the error by which the {@link module:watchdog/watchdog~Watchdog watchdog}
+	 * is able to determine which editor crashed. It should be an editor instance or a property connected to it. It can be also
+	 * a `null` value if the editor should not be restarted in case of the error (e.g. during the editor initialization).
+	 * The error context should be checked using the `areConnectedThroughProperties( editor, context )` utility
+	 * to check if the object works as the context.
 	 * @param {Object} [data] Additional data describing the error. A stringified version of this object
 	 * will be appended to the error message, so the data are quickly visible in the console. The original
 	 * data object will also be later available under the {@link #data} property.
 	 */
-	constructor( message, data ) {
+	constructor( message, context, data ) {
 		message = attachLinkToDocumentation( message );
 
 		if ( data ) {
@@ -46,26 +51,30 @@ export default class CKEditorError extends Error {
 		super( message );
 
 		/**
-		 * @member {String}
+		 * @type {String}
 		 */
 		this.name = 'CKEditorError';
 
+		/**
+		 * A context of the error by which the Watchdog is able to determine which editor crashed.
+		 *
+		 * @type {Object|null}
+		 */
+		this.context = context;
+
 		/**
 		 * The additional error data passed to the constructor. Undefined if none was passed.
 		 *
-		 * @member {Object|undefined}
+		 * @type {Object|undefined}
 		 */
 		this.data = data;
 	}
 
 	/**
-	 * Checks if error is an instance of CKEditorError class.
-	 *
-	 * @param {Object} error Object to check.
-	 * @returns {Boolean}
+	 * Checks if the error is of the `CKEditorError` type.
 	 */
-	static isCKEditorError( error ) {
-		return error instanceof CKEditorError;
+	is( type ) {
+		return type === 'CKEditorError';
 	}
 }
 

src/collection.js

@@ -148,7 +148,7 @@ export default class Collection {
 				 *
 				 * @error collection-add-invalid-id
 				 */
-				throw new CKEditorError( 'collection-add-invalid-id' );
+				throw new CKEditorError( 'collection-add-invalid-id', this );
 			}
 
 			if ( this.get( itemId ) ) {
@@ -157,7 +157,7 @@ export default class Collection {
 				 *
 				 * @error collection-add-item-already-exists
 				 */
-				throw new CKEditorError( 'collection-add-item-already-exists' );
+				throw new CKEditorError( 'collection-add-item-already-exists', this );
 			}
 		} else {
 			item[ idProperty ] = itemId = uid();
@@ -172,7 +172,7 @@ export default class Collection {
 			 *
 			 * @error collection-add-item-bad-index
 			 */
-			throw new CKEditorError( 'collection-add-item-invalid-index' );
+			throw new CKEditorError( 'collection-add-item-invalid-index', this );
 		}
 
 		this._items.splice( index, 0, item );
@@ -203,7 +203,7 @@ export default class Collection {
 			 *
 			 * @error collection-get-invalid-arg
 			 */
-			throw new CKEditorError( 'collection-get-invalid-arg: Index or id must be given.' );
+			throw new CKEditorError( 'collection-get-invalid-arg: Index or id must be given.', this );
 		}
 
 		return item || null;
@@ -286,7 +286,7 @@ export default class Collection {
 			 *
 			 * @error collection-remove-404
 			 */
-			throw new CKEditorError( 'collection-remove-404: Item not found.' );
+			throw new CKEditorError( 'collection-remove-404: Item not found.', this );
 		}
 
 		this._items.splice( index, 1 );
@@ -459,7 +459,7 @@ export default class Collection {
 			 *
 			 * @error collection-bind-to-rebind
 			 */
-			throw new CKEditorError( 'collection-bind-to-rebind: The collection cannot be bound more than once.' );
+			throw new CKEditorError( 'collection-bind-to-rebind: The collection cannot be bound more than once.', this );
 		}
 
 		this._bindToCollection = externalCollection;

src/focustracker.js

@@ -75,7 +75,7 @@ export default class FocusTracker {
 	 */
 	add( element ) {
 		if ( this._elements.has( element ) ) {
-			throw new CKEditorError( 'focusTracker-add-element-already-exist' );
+			throw new CKEditorError( 'focusTracker-add-element-already-exist', this );
 		}
 
 		this.listenTo( element, 'focus', () => this._focus( element ), { useCapture: true } );

src/keyboard.js

@@ -60,7 +60,10 @@ export function getCode( key ) {
 			 * @errror keyboard-unknown-key
 			 * @param {String} key
 			 */
-			throw new CKEditorError( 'keyboard-unknown-key: Unknown key name.', { key } );
+			throw new CKEditorError(
+				'keyboard-unknown-key: Unknown key name.',
+				null, { key }
+			);
 		}
 	} else {
 		keyCode = key.keyCode +

src/observablemixin.js

@@ -62,7 +62,7 @@ const ObservableMixin = {
 			 *
 			 * @error observable-set-cannot-override
 			 */
-			throw new CKEditorError( 'observable-set-cannot-override: Cannot override an existing property.' );
+			throw new CKEditorError( 'observable-set-cannot-override: Cannot override an existing property.', this );
 		}
 
 		Object.defineProperty( this, name, {
@@ -107,7 +107,7 @@ const ObservableMixin = {
 			 *
 			 * @error observable-bind-wrong-properties
 			 */
-			throw new CKEditorError( 'observable-bind-wrong-properties: All properties must be strings.' );
+			throw new CKEditorError( 'observable-bind-wrong-properties: All properties must be strings.', this );
 		}
 
 		if ( ( new Set( bindProperties ) ).size !== bindProperties.length ) {
@@ -116,7 +116,7 @@ const ObservableMixin = {
 			 *
 			 * @error observable-bind-duplicate-properties
 			 */
-			throw new CKEditorError( 'observable-bind-duplicate-properties: Properties must be unique.' );
+			throw new CKEditorError( 'observable-bind-duplicate-properties: Properties must be unique.', this );
 		}
 
 		initObservable( this );
@@ -130,7 +130,7 @@ const ObservableMixin = {
 				 *
 				 * @error observable-bind-rebind
 				 */
-				throw new CKEditorError( 'observable-bind-rebind: Cannot bind the same property more that once.' );
+				throw new CKEditorError( 'observable-bind-rebind: Cannot bind the same property more that once.', this );
 			}
 		} );
 
@@ -186,7 +186,7 @@ const ObservableMixin = {
 				 *
 				 * @error observable-unbind-wrong-properties
 				 */
-				throw new CKEditorError( 'observable-unbind-wrong-properties: Properties must be strings.' );
+				throw new CKEditorError( 'observable-unbind-wrong-properties: Properties must be strings.', this );
 			}
 
 			unbindProperties.forEach( propertyName => {
@@ -246,6 +246,7 @@ const ObservableMixin = {
 			 */
 			throw new CKEditorError(
 				'observablemixin-cannot-decorate-undefined: Cannot decorate an undefined method.',
+				this,
 				{ object: this, methodName }
 			);
 		}
@@ -380,7 +381,10 @@ function bindTo( ...args ) {
 		 *
 		 * @error observable-bind-no-callback
 		 */
-		throw new CKEditorError( 'observable-bind-to-no-callback: Binding multiple observables only possible with callback.' );
+		throw new CKEditorError(
+			'observable-bind-to-no-callback: Binding multiple observables only possible with callback.',
+			this
+		);
 	}
 
 	// Eliminate A.bind( 'x', 'y' ).to( B, callback )
@@ -390,7 +394,10 @@ function bindTo( ...args ) {
 		 *
 		 * @error observable-bind-to-extra-callback
 		 */
-		throw new CKEditorError( 'observable-bind-to-extra-callback: Cannot bind multiple properties and use a callback in one binding.' );
+		throw new CKEditorError(
+			'observable-bind-to-extra-callback: Cannot bind multiple properties and use a callback in one binding.',
+			this
+		);
 	}
 
 	parsedArgs.to.forEach( to => {
@@ -401,7 +408,7 @@ function bindTo( ...args ) {
 			 *
 			 * @error observable-bind-to-properties-length
 			 */
-			throw new CKEditorError( 'observable-bind-to-properties-length: The number of properties must match.' );
+			throw new CKEditorError( 'observable-bind-to-properties-length: The number of properties must match.', this );
 		}
 
 		// When no to.properties specified, observing source properties instead i.e.
@@ -442,7 +449,7 @@ function bindToMany( observables, attribute, callback ) {
 		 *
 		 * @error observable-bind-to-many-not-one-binding
 		 */
-		throw new CKEditorError( 'observable-bind-to-many-not-one-binding: Cannot bind multiple properties with toMany().' );
+		throw new CKEditorError( 'observable-bind-to-many-not-one-binding: Cannot bind multiple properties with toMany().', this );
 	}
 
 	this.to(
@@ -501,7 +508,7 @@ function parseBindToArgs( ...args ) {
 		 *
 		 * @error observable-bind-to-parse-error
 		 */
-		throw new CKEditorError( 'observable-bind-to-parse-error: Invalid argument syntax in `to()`.' );
+		throw new CKEditorError( 'observable-bind-to-parse-error: Invalid argument syntax in `to()`.', null );
 	}
 
 	const parsed = { to: [] };
@@ -518,7 +525,7 @@ function parseBindToArgs( ...args ) {
 			lastObservable = { observable: a, properties: [] };
 			parsed.to.push( lastObservable );
 		} else {
-			throw new CKEditorError( 'observable-bind-to-parse-error: Invalid argument syntax in `to()`.' );
+			throw new CKEditorError( 'observable-bind-to-parse-error: Invalid argument syntax in `to()`.', null );
 		}
 	} );