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Remove redundant compatibility checks, for modern generic builds, in src/core/worker.js

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With the recent additions of optional chaining and nullish coalescing to the PDF.js code-base, a couple of the checks in `src/core/worker.js` are now redundant; please see this compatibility information:
 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining#browser_compatibility
 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator#browser_compatibility

In practice, for the non-translated/non-polyfilled PDF.js builds, browsers without support for optional chaining and nullish coalescing will simply throw immediately upon loading of the code.
Hence both the `globalThis` and `Promise.allSettled` checks are now unnecessary, given this compatibility information:
 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis#browser_compatibility
 - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/allSettled#browser_compatibility

*Please note:* The `ReadableStream` check is however still necessary, since Node.js doesn't support that.
This commit is contained in:
Jonas Jenwald 2021-01-20 13:09:56 +01:00
parent a10dc1cb6e
commit b4eb55250e
1 changed files with 4 additions and 8 deletions
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12
src/core/worker.js
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@ -139,19 +139,15 @@ class WorkerMessageHandler {
// Ensure that (primarily) Node.js users won't accidentally attempt to use
// a non-translated/non-polyfilled build of the library, since that would
// quickly fail anyway because of missing functionality (such as e.g.
// `ReadableStream` and `Promise.allSettled`).
// quickly fail anyway because of missing functionality.
if (
(typeof PDFJSDev === "undefined" || PDFJSDev.test("SKIP_BABEL")) &&
(typeof globalThis === "undefined" ||
typeof ReadableStream === "undefined" ||
typeof Promise.allSettled === "undefined")
typeof ReadableStream === "undefined"
) {
throw new Error(
"The browser/environment lacks native support for critical " +
"functionality used by the PDF.js library (e.g. `globalThis`, " +
"`ReadableStream`, and/or `Promise.allSettled`); " +
"please use an ES5-compatible build instead."
"functionality used by the PDF.js library (e.g. `ReadableStream`); " +
"please use an `es5`-build instead."
);
}
}