mediocre-blog/assets/viz/2/goog/dom/asserts.js

312 lines
11 KiB
JavaScript

// Copyright 2017 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
goog.provide('goog.dom.asserts');
goog.require('goog.asserts');
/**
* @fileoverview Custom assertions to ensure that an element has the appropriate
* type.
*
* Using a goog.dom.safe wrapper on an object on the incorrect type (via an
* incorrect static type cast) can result in security bugs: For instance,
* g.d.s.setAnchorHref ensures that the URL assigned to the .href attribute
* satisfies the SafeUrl contract, i.e., is safe to dereference as a hyperlink.
* However, the value assigned to a HTMLLinkElement's .href property requires
* the stronger TrustedResourceUrl contract, since it can refer to a stylesheet.
* Thus, using g.d.s.setAnchorHref on an (incorrectly statically typed) object
* of type HTMLLinkElement can result in a security vulnerability.
* Assertions of the correct run-time type help prevent such incorrect use.
*
* In some cases, code using the DOM API is tested using mock objects (e.g., a
* plain object such as {'href': url} instead of an actual Location object).
* To allow such mocking, the assertions permit objects of types that are not
* relevant DOM API objects at all (for instance, not Element or Location).
*
* Note that instanceof checks don't work straightforwardly in older versions of
* IE, or across frames (see,
* http://stackoverflow.com/questions/384286/javascript-isdom-how-do-you-check-if-a-javascript-object-is-a-dom-object,
* http://stackoverflow.com/questions/26248599/instanceof-htmlelement-in-iframe-is-not-element-or-object).
*
* Hence, these assertions may pass vacuously in such scenarios. The resulting
* risk of security bugs is limited by the following factors:
* - A bug can only arise in scenarios involving incorrect static typing (the
* wrapper methods are statically typed to demand objects of the appropriate,
* precise type).
* - Typically, code is tested and exercised in multiple browsers.
*/
/**
* Asserts that a given object is a Location.
*
* To permit this assertion to pass in the context of tests where DOM APIs might
* be mocked, also accepts any other type except for subtypes of {!Element}.
* This is to ensure that, for instance, HTMLLinkElement is not being used in
* place of a Location, since this could result in security bugs due to stronger
* contracts required for assignments to the href property of the latter.
*
* @param {?Object} o The object whose type to assert.
* @return {!Location}
*/
goog.dom.asserts.assertIsLocation = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.Location != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o && (o instanceof win.Location || !(o instanceof win.Element)),
'Argument is not a Location (or a non-Element mock); got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!Location} */ (o);
};
/**
* Asserts that a given object is a HTMLAnchorElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not of type Location nor a subtype
* of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLAnchorElement}
*/
goog.dom.asserts.assertIsHTMLAnchorElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLAnchorElement != 'undefined' &&
typeof win.Location != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLAnchorElement ||
!((o instanceof win.Location) || (o instanceof win.Element))),
'Argument is not a HTMLAnchorElement (or a non-Element mock); ' +
'got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLAnchorElement} */ (o);
};
/**
* Asserts that a given object is a HTMLLinkElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLLinkElement}
*/
goog.dom.asserts.assertIsHTMLLinkElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLLinkElement != 'undefined' &&
typeof win.Location != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLLinkElement ||
!((o instanceof win.Location) || (o instanceof win.Element))),
'Argument is not a HTMLLinkElement (or a non-Element mock); got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLLinkElement} */ (o);
};
/**
* Asserts that a given object is a HTMLImageElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLImageElement}
*/
goog.dom.asserts.assertIsHTMLImageElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLImageElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLImageElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLImageElement (or a non-Element mock); got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLImageElement} */ (o);
};
/**
* Asserts that a given object is a HTMLEmbedElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLEmbedElement}
*/
goog.dom.asserts.assertIsHTMLEmbedElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLEmbedElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLEmbedElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLEmbedElement (or a non-Element mock); got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLEmbedElement} */ (o);
};
/**
* Asserts that a given object is a HTMLFrameElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLFrameElement}
*/
goog.dom.asserts.assertIsHTMLFrameElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLFrameElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLFrameElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLFrameElement (or a non-Element mock); got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLFrameElement} */ (o);
};
/**
* Asserts that a given object is a HTMLIFrameElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLIFrameElement}
*/
goog.dom.asserts.assertIsHTMLIFrameElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLIFrameElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLIFrameElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLIFrameElement (or a non-Element mock); ' +
'got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLIFrameElement} */ (o);
};
/**
* Asserts that a given object is a HTMLObjectElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLObjectElement}
*/
goog.dom.asserts.assertIsHTMLObjectElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLObjectElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLObjectElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLObjectElement (or a non-Element mock); ' +
'got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLObjectElement} */ (o);
};
/**
* Asserts that a given object is a HTMLScriptElement.
*
* To permit this assertion to pass in the context of tests where elements might
* be mocked, also accepts objects that are not a subtype of Element.
*
* @param {?Object} o The object whose type to assert.
* @return {!HTMLScriptElement}
*/
goog.dom.asserts.assertIsHTMLScriptElement = function(o) {
if (goog.asserts.ENABLE_ASSERTS) {
var win = goog.dom.asserts.getWindow_(o);
if (typeof win.HTMLScriptElement != 'undefined' &&
typeof win.Element != 'undefined') {
goog.asserts.assert(
o &&
(o instanceof win.HTMLScriptElement ||
!(o instanceof win.Element)),
'Argument is not a HTMLScriptElement (or a non-Element mock); ' +
'got: %s',
goog.dom.asserts.debugStringForType_(o));
}
}
return /** @type {!HTMLScriptElement} */ (o);
};
/**
* Returns a string representation of a value's type.
*
* @param {*} value An object, or primitive.
* @return {string} The best display name for the value.
* @private
*/
goog.dom.asserts.debugStringForType_ = function(value) {
if (goog.isObject(value)) {
return value.constructor.displayName || value.constructor.name ||
Object.prototype.toString.call(value);
} else {
return value === undefined ? 'undefined' :
value === null ? 'null' : typeof value;
}
};
/**
* Gets window of element.
* @param {?Object} o
* @return {!Window}
* @private
*/
goog.dom.asserts.getWindow_ = function(o) {
var doc = o && o.ownerDocument;
var win = doc && /** @type {?Window} */ (doc.defaultView || doc.parentWindow);
return win || /** @type {!Window} */ (goog.global);
};