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[api-minor] Replace the PromiseCapability with Promise.withResolvers()

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This replaces our custom `PromiseCapability`-class with the new native `Promise.withResolvers()` functionality, which does *almost* the same thing[1]; please see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers

The only difference is that `PromiseCapability` also had a `settled`-getter, which was however not widely used and the call-sites can either be removed or re-factored to avoid it. In particular:
 - In `src/display/api.js` we can tweak the `PDFObjects`-class to use a "special" initial data-value and just compare against that, in order to replace the `settled`-state.
 - In `web/app.js` we change the only case to manually track the `settled`-state, which should hopefully be OK given how this is being used.
 - In `web/pdf_outline_viewer.js` we can remove the `settled`-checks, since the code should work just fine without it. The only thing that could potentially happen is that we try to `resolve` a Promise multiple times, which is however *not* a problem since the value of a Promise cannot be changed once fulfilled or rejected.
 - In `web/pdf_viewer.js` we can remove the `settled`-checks, since the code should work fine without them:
     - For the `_onePageRenderedCapability` case the `settled`-check is used in a `EventBus`-listener which is *removed* on its first (valid) invocation.
     - For the `_pagesCapability` case the `settled`-check is used in a print-related helper that works just fine with "only" the other checks.
 - In `test/unit/api_spec.js` we can change the few relevant cases to manually track the `settled`-state, since this is both simple and *test-only* code.

---
[1] In browsers/environments that lack native support, note [the compatibility data](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers#browser_compatibility), it'll be polyfilled via the `core-js` library (but only in `legacy` builds).
This commit is contained in:
Jonas Jenwald 2024-03-28 16:42:37 +01:00
parent 55db43966e
commit e4d0e84802
28 changed files with 159 additions and 252 deletions
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26
gulpfile.mjs
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@ -99,6 +99,13 @@ const AUTOPREFIXER_CONFIG = {
// Default Babel targets used for generic, components, minified-pre
const BABEL_TARGETS = ENV_TARGETS.join(", ");
const BABEL_PRESET_ENV_OPTS = Object.freeze({
corejs: "3.36.1",
exclude: ["web.structured-clone"],
shippedProposals: true,
useBuiltIns: "usage",
});
const DEFINES = Object.freeze({
SKIP_BABEL: true,
TESTING: undefined,
@ -303,17 +310,7 @@ function createWebpackConfig(
const babelPresets = skipBabel
? undefined
: [
[
"@babel/preset-env",
{
corejs: "3.36.1",
exclude: ["web.structured-clone"],
shippedProposals: true,
useBuiltIns: "usage",
},
],
];
: [["@babel/preset-env", BABEL_PRESET_ENV_OPTS]];
const babelPlugins = [
[
babelPluginPDFJSPreprocessor,
@ -1542,7 +1539,12 @@ function buildLibHelper(bundleDefines, inputStream, outputDir) {
sourceType: "module",
presets: skipBabel
? undefined
: [["@babel/preset-env", { loose: false, modules: false }]],
: [
[
"@babel/preset-env",
{ ...BABEL_PRESET_ENV_OPTS, loose: false, modules: false },
],
],
plugins: [[babelPluginPDFJSPreprocessor, ctx]],
targets: BABEL_TARGETS,
}).code;