pdf.js/src/shared/compatibility.js
Jonas Jenwald 710704508c Fail early, in modern GENERIC builds, if certain required browser functionality is missing (issue 11762)
With two kind of builds now being produced, with/without translation/polyfills, it's unfortunately somewhat easy for users to accidentally pick the wrong one.

In the case where a user would attempt to use a modern build of PDF.js in an older browser, such as e.g. IE11, the failure would be immediate when the code is loaded (given the use of unsupported ECMAScript features).
However in some browsers/environments, in particular Node.js, a modern PDF.js build may load correctly and thus *appear* to function, only to fail for e.g. certain API calls. To hopefully lessen the support burden, and to try and improve things overall, this patch adds checks to ensure that a modern build of PDF.js cannot be used in browsers/environments which lack native support for critical functionality (such as e.g. `ReadableStream`). Hence we'll fail early, with an error message telling users to pick an ES5-compatible build instead.

To ensure that we actually test things better especially w.r.t. usage of the PDF.js library in Node.js environments, the `gulp npm-test` task as used by Node.js/Travis was changed (back) to test an ES5-compatible build.
(Since the bots still test the code as-is, without transpilation/polyfills, this shouldn't really be a problem as far as I can tell.)
As part of these changes there's now both `gulp lib` and `gulp lib-es5` build targets, similar to e.g. the generic builds, which thanks to some re-factoring only required adding a small amount of code.

*Please note:* While it's probably too early to tell if this will be a widespread issue, it's possible that this is the sort of patch that *may* warrant being `git cherry-pick`ed onto the current beta version (v2.4.456).
2020-04-01 19:42:48 +02:00

373 lines
11 KiB
JavaScript

/* Copyright 2017 Mozilla Foundation
*
* 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.
*/
/* eslint no-var: error */
// Skip compatibility checks for modern builds and if we already ran the module.
if (
(typeof PDFJSDev === "undefined" || !PDFJSDev.test("SKIP_BABEL")) &&
(typeof globalThis === "undefined" || !globalThis._pdfjsCompatibilityChecked)
) {
// Provides support for globalThis in legacy browsers.
// Support: IE11/Edge, Opera
if (typeof globalThis === "undefined" || globalThis.Math !== Math) {
// eslint-disable-next-line no-global-assign
globalThis = require("core-js/es/global-this");
}
globalThis._pdfjsCompatibilityChecked = true;
const { isNodeJS } = require("./is_node.js");
const hasDOM = typeof window === "object" && typeof document === "object";
const userAgent =
(typeof navigator !== "undefined" && navigator.userAgent) || "";
const isIE = /Trident/.test(userAgent);
// Support: Node.js
(function checkNodeBtoa() {
if (globalThis.btoa || !isNodeJS) {
return;
}
globalThis.btoa = function(chars) {
// eslint-disable-next-line no-undef
return Buffer.from(chars, "binary").toString("base64");
};
})();
// Support: Node.js
(function checkNodeAtob() {
if (globalThis.atob || !isNodeJS) {
return;
}
globalThis.atob = function(input) {
// eslint-disable-next-line no-undef
return Buffer.from(input, "base64").toString("binary");
};
})();
// Provides support for ChildNode.remove in legacy browsers.
// Support: IE.
(function checkChildNodeRemove() {
if (!hasDOM) {
return;
}
if (typeof Element.prototype.remove !== "undefined") {
return;
}
Element.prototype.remove = function() {
if (this.parentNode) {
// eslint-disable-next-line mozilla/avoid-removeChild
this.parentNode.removeChild(this);
}
};
})();
// Provides support for DOMTokenList.prototype.{add, remove}, with more than
// one parameter, in legacy browsers.
// Support: IE
(function checkDOMTokenListAddRemove() {
if (!hasDOM || isNodeJS) {
return;
}
const div = document.createElement("div");
div.classList.add("testOne", "testTwo");
if (
div.classList.contains("testOne") === true &&
div.classList.contains("testTwo") === true
) {
return;
}
const OriginalDOMTokenListAdd = DOMTokenList.prototype.add;
const OriginalDOMTokenListRemove = DOMTokenList.prototype.remove;
DOMTokenList.prototype.add = function(...tokens) {
for (const token of tokens) {
OriginalDOMTokenListAdd.call(this, token);
}
};
DOMTokenList.prototype.remove = function(...tokens) {
for (const token of tokens) {
OriginalDOMTokenListRemove.call(this, token);
}
};
})();
// Provides support for DOMTokenList.prototype.toggle, with the optional
// "force" parameter, in legacy browsers.
// Support: IE
(function checkDOMTokenListToggle() {
if (!hasDOM || isNodeJS) {
return;
}
const div = document.createElement("div");
if (div.classList.toggle("test", 0) === false) {
return;
}
DOMTokenList.prototype.toggle = function(token) {
const force =
arguments.length > 1 ? !!arguments[1] : !this.contains(token);
return this[force ? "add" : "remove"](token), force;
};
})();
// Provides support for window.history.{pushState, replaceState}, with the
// `url` parameter set to `undefined`, without breaking the document URL.
// Support: IE
(function checkWindowHistoryPushStateReplaceState() {
if (!hasDOM || !isIE) {
return;
}
const OriginalPushState = window.history.pushState;
const OriginalReplaceState = window.history.replaceState;
window.history.pushState = function(state, title, url) {
const args = url === undefined ? [state, title] : [state, title, url];
OriginalPushState.apply(this, args);
};
window.history.replaceState = function(state, title, url) {
const args = url === undefined ? [state, title] : [state, title, url];
OriginalReplaceState.apply(this, args);
};
})();
// Provides support for String.prototype.startsWith in legacy browsers.
// Support: IE, Chrome<41
(function checkStringStartsWith() {
if (String.prototype.startsWith) {
return;
}
require("core-js/es/string/starts-with.js");
})();
// Provides support for String.prototype.endsWith in legacy browsers.
// Support: IE, Chrome<41
(function checkStringEndsWith() {
if (String.prototype.endsWith) {
return;
}
require("core-js/es/string/ends-with.js");
})();
// Provides support for String.prototype.includes in legacy browsers.
// Support: IE, Chrome<41
(function checkStringIncludes() {
if (String.prototype.includes) {
return;
}
require("core-js/es/string/includes.js");
})();
// Provides support for Array.prototype.includes in legacy browsers.
// Support: IE, Chrome<47
(function checkArrayIncludes() {
if (Array.prototype.includes) {
return;
}
require("core-js/es/array/includes.js");
})();
// Provides support for Array.from in legacy browsers.
// Support: IE
(function checkArrayFrom() {
if (Array.from) {
return;
}
require("core-js/es/array/from.js");
})();
// Provides support for Object.assign in legacy browsers.
// Support: IE
(function checkObjectAssign() {
if (Object.assign) {
return;
}
require("core-js/es/object/assign.js");
})();
// Provides support for Math.log2 in legacy browsers.
// Support: IE, Chrome<38
(function checkMathLog2() {
if (Math.log2) {
return;
}
Math.log2 = require("core-js/es/math/log2.js");
})();
// Provides support for Number.isNaN in legacy browsers.
// Support: IE.
(function checkNumberIsNaN() {
if (Number.isNaN) {
return;
}
Number.isNaN = require("core-js/es/number/is-nan.js");
})();
// Provides support for Number.isInteger in legacy browsers.
// Support: IE, Chrome<34
(function checkNumberIsInteger() {
if (Number.isInteger) {
return;
}
Number.isInteger = require("core-js/es/number/is-integer.js");
})();
// Support: IE, Safari<11, Chrome<63
(function checkPromise() {
if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("IMAGE_DECODERS")) {
// The current image decoders are synchronous, hence `Promise` shouldn't
// need to be polyfilled for the IMAGE_DECODERS build target.
return;
}
if (globalThis.Promise && globalThis.Promise.allSettled) {
return;
}
globalThis.Promise = require("core-js/es/promise/index.js");
})();
// Support: IE
(function checkURL() {
if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("IMAGE_DECODERS")) {
// The current image decoders don't use the `URL` constructor, so it
// doesn't need to be polyfilled for the IMAGE_DECODERS build target.
return;
}
if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("GENERIC")) {
// The `URL` constructor is assumed to be available in the extension
// builds.
return;
}
globalThis.URL = require("core-js/web/url.js");
})();
// Support: IE, Node.js
(function checkReadableStream() {
if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("IMAGE_DECODERS")) {
// The current image decoders are synchronous, hence `ReadableStream`
// shouldn't need to be polyfilled for the IMAGE_DECODERS build target.
return;
}
let isReadableStreamSupported = false;
if (typeof ReadableStream !== "undefined") {
// MS Edge may say it has ReadableStream but they are not up to spec yet.
try {
// eslint-disable-next-line no-new
new ReadableStream({
start(controller) {
controller.close();
},
});
isReadableStreamSupported = true;
} catch (e) {
// The ReadableStream constructor cannot be used.
}
}
if (isReadableStreamSupported) {
return;
}
globalThis.ReadableStream = require("web-streams-polyfill/dist/ponyfill.js").ReadableStream;
})();
// We want to support Map iteration, but it doesn't seem possible to easily
// test for that specifically; hence using a similarly unsupported property.
// Support: IE11
(function checkMapEntries() {
if (globalThis.Map && globalThis.Map.prototype.entries) {
return;
}
globalThis.Map = require("core-js/es/map/index.js");
})();
// We want to support Set iteration, but it doesn't seem possible to easily
// test for that specifically; hence using a similarly unsupported property.
// Support: IE11
(function checkSetEntries() {
if (globalThis.Set && globalThis.Set.prototype.entries) {
return;
}
globalThis.Set = require("core-js/es/set/index.js");
})();
// Support: IE<11, Safari<8, Chrome<36
(function checkWeakMap() {
if (globalThis.WeakMap) {
return;
}
globalThis.WeakMap = require("core-js/es/weak-map/index.js");
})();
// Support: IE11
(function checkWeakSet() {
if (globalThis.WeakSet) {
return;
}
globalThis.WeakSet = require("core-js/es/weak-set/index.js");
})();
// Provides support for String.codePointAt in legacy browsers.
// Support: IE11.
(function checkStringCodePointAt() {
if (String.prototype.codePointAt) {
return;
}
require("core-js/es/string/code-point-at.js");
})();
// Provides support for String.fromCodePoint in legacy browsers.
// Support: IE11.
(function checkStringFromCodePoint() {
if (String.fromCodePoint) {
return;
}
String.fromCodePoint = require("core-js/es/string/from-code-point.js");
})();
// Support: IE
(function checkSymbol() {
if (globalThis.Symbol) {
return;
}
require("core-js/es/symbol/index.js");
})();
// Provides support for String.prototype.padStart in legacy browsers.
// Support: IE, Chrome<57
(function checkStringPadStart() {
if (String.prototype.padStart) {
return;
}
require("core-js/es/string/pad-start.js");
})();
// Provides support for String.prototype.padEnd in legacy browsers.
// Support: IE, Chrome<57
(function checkStringPadEnd() {
if (String.prototype.padEnd) {
return;
}
require("core-js/es/string/pad-end.js");
})();
// Provides support for Object.values in legacy browsers.
// Support: IE, Chrome<54
(function checkObjectValues() {
if (Object.values) {
return;
}
Object.values = require("core-js/es/object/values.js");
})();
}