The `merge-stream` dependency is no longer maintained and doesn't work
in combination with Gulp 5 anymore (for more information refer to
https://github.com/gulpjs/gulp/issues/2802#issuecomment-2094130656).
Fortunately the Gulp team maintains a drop-in replacement dependency
called `ordered-read-streams` with the same API as `merge-stream`.
Indeed, running all affected Gulp targets and comparing build artifacts
with `diff -r <old> <new>` confirms that no unexpected changes are made.
Fixes a part of #17922.
The `through2` dependency got introduced over four years ago in #11325 to
replace the unmaintained `gulp-transform` dependency. However, sadly the
same holds for `through2` since the last release was also four years ago.
Fortunately the `through2` dependency can trivially be replaced with the
built-in Node.js `stream.Transform` API nowadays. In fact, the `through2`
dependency mentions themselves in their README already that they are "a
tiny wrapper around Node.js streams.Transform". The `stream.Transform`
API is available in all Node.js versions we support, and in Node.js 6
already the simplified constructor approach for `stream.Transform` got
introduced to simplify creating custom stream transformers; see
https://nodejs.org/docs/latest-v6.x/api/stream.html#stream_new_stream_transform_options.
This commit therefore replaces `through2` by switching to the
`stream.Transform` API directly so we don't need any wrappers anymore.
Note that for our case the only change we have to make is to enable
object mode, see https://nodejs.org/api/stream.html#object-mode, because
we pass in `VinylFile` objects instead of e.g. regular `Buffer` objects.
I have confirmed in two ways that this is indeed a drop-in replacement:
- Running the Gulp targets that call the `transform` function and
diffing the resulting `build` folder before/after this patch, with
`diff -r build-old/ build-new/`, to ensure that there are no
unexpected changes in the output.
- Changing the Gulpfile to, instead of UTF-8, transform the files to
ASCII, and diffing the resulting `build` folder to confirm that the
transformation logic works and produces different results, such as:
```
diff build/lib/core/standard_fonts.js build-ascii/lib/core/standard_fonts.js
284c284
< t["Trinité"] = true;
---
> t["Trinit�"] = true;
```
The `needle` dependency originally got introduced in #12024, almost four
years ago, to be able to use pre-built binaries for the `canvas`
dependency on macOS. However, nowadays the `needle` dependency isn't
used by `canvas` anymore, or any other package we use for that matter,
as shown by the empty NPM dependency tree:
```
$ npm ls needle
pdf.js
└── needle@3.3.1
```
Investigation showed that the `canvas` package depends on the
`node-pre-gyp` package which in turn depended on `needle` (see
https://github.com/Automattic/node-canvas/issues/1110#issuecomment-411232630),
but in version 1.0.0 of `node-pre-gyp` from three years ago the `needle`
dependency got dropped in favor of `node-fetch` (see
a74f5e367c/CHANGELOG.md (L52)).
This explains why the NPM dependency tree is empty now and proves that
we can safely get rid of this dependency now.
In Node.js 14.14.0 the `fs.rmSync` function was added that removes files
and directories. The `recursive` option is used to remove directories
and their contents, making it a drop-in replacement for the `rimraf`
dependency we use.
Given that PDF.js now requires Node.js 18+ we can be sure that this
option is available, so we can safely remove `rimraf` and reduce the
number of project dependencies.
Co-authored-by: Wojciech Maj <kontakt@wojtekmaj.pl>
The Puppeteer update should in particular be helpful for us because it
contains improved WebDriver BiDi compatibility, a newer Chrome version
(both might help for #17962) and an official deprecation of CDP for
Firefox. Note that the latter doesn't require changes on our end because
we already use WebDriver BiDi unconditionally for Firefox since commit
4db0174. The full release notes can be found at
https://github.com/puppeteer/puppeteer/releases/tag/puppeteer-core-v22.8.0.
In Node.js 10.12.0 the `recursive` option was added to `fs.mkdirSync`.
This option allows us to create a directory and all its parent
directories if they do not exist, making it a drop-in replacement for
the `mkdirp` dependency we use.
Given that PDF.js now requires Node.js 18+ we can be sure that this
option is available, so we can safely remove `mkdirp` and reduce the
number of project dependencies.
Co-authored-by: Wojciech Maj <kontakt@wojtekmaj.pl>
Rather than first building the library and then use Terser "manually" to minify the files, we can utilize a Webpack plugin to combine these steps which helps to simplify the gulpfile.
This commit converts the pdfjsdev-loader transform into a Babel plugin,
to skip a AST->string->AST round-trip.
Before this commit, the webpack build process was:
1. Babel parses the code
2. Babel transforms the AST
3. Babel generates the code
4. Acorn parses the code
5. pdfjsdev-loader transforms the AST
6. @javascript-obfuscator/escodegen generates the code
7. Webpack parses the file
8. Webpack concatenates the files
After this commit, it is reduced to:
1. Babel parses the code
2. Babel transforms the AST
3. babel-plugin-pdfjs-preprocessor transforms the AST
4. Babel generates the code
5. Webpack parses the file
6. Webpack concatenates the files
This change improves the build time by ~25% (tested on MacBook Air M2):
- `gulp lib`: 3.4s to 2.6s
- `gulp dist`: 36s to 29s
- `gulp generic`: 5.5s to 4.0s
- `gulp mozcentral`: 4.7s to 3.2s
The new Babel plugin doesn't support the `saveComments` option of
pdfjsdev-loader, and it just always discards comments. Even though
pdfjsdev-loader supported multiple values for that option, it was
effectively ignored due to `acorn` dropping comments by default.
- For the generic viewer we use @fluent/dom and @fluent/bundle
- For the builtin pdf viewer in Firefox, we set a localization url
and then we rely on document.l10n which is a DOMLocalization object.
This *finally* allows us to mark the entire PDF.js library as a "module", which should thus conclude the (multi-year) effort to re-factor and improve how we import files/resources in the code-base.
This also means that the `gulp ci-test` target, which is what's run in GitHub Actions, now uses JavaScript modules since that's supported in modern Node.js versions.
