This patch is an attempt at closing an old, and seemingly trivial, issue and the SVG-files created by the `pdf2svg.js` examples still appear to work just fine when opened in browsers (tested with Firefox Nightly and Google Chrome Beta).
Please note that these changes were done automatically, using `gulp lint --fix`.
Given that the major version number was increased, there's a fair number of (primarily whitespace) changes; please see https://prettier.io/blog/2020/03/21/2.0.0.html
In order to reduce the size of these changes somewhat, this patch maintains the old "arrowParens" style for now (once mozilla-central updates Prettier we can simply choose the same formatting, assuming it will differ here).
Note that Prettier, purposely, has only limited [configuration options](https://prettier.io/docs/en/options.html). The configuration file is based on [the one in `mozilla central`](https://searchfox.org/mozilla-central/source/.prettierrc) with just a few additions (to avoid future breakage if the defaults ever changes).
Prettier is being used for a couple of reasons:
- To be consistent with `mozilla-central`, where Prettier is already in use across the tree.
- To ensure a *consistent* coding style everywhere, which is automatically enforced during linting (since Prettier is used as an ESLint plugin). This thus ends "all" formatting disussions once and for all, removing the need for review comments on most stylistic matters.
Many ESLint options are now redundant, and I've tried my best to remove all the now unnecessary options (but I may have missed some).
Note also that since Prettier considers the `printWidth` option as a guide, rather than a hard rule, this patch resorts to a small hack in the ESLint config to ensure that *comments* won't become too long.
*Please note:* This patch is generated automatically, by appending the `--fix` argument to the ESLint call used in the `gulp lint` task. It will thus require some additional clean-up, which will be done in a *separate* commit.
(On a more personal note, I'll readily admit that some of the changes Prettier makes are *extremely* ugly. However, in the name of consistency we'll probably have to live with that.)
These were removed in PR 9170, since they were unused in the browsers that we'll support in PDF.js version `2.0`.
However looking at the output of Travis, where a subset of the unit-tests are run using Node.js, there's warnings about `btoa` being undefined. This doesn't appear to cause any errors, which probably explains why we didn't notice this before (despite PR 9201).
Implement a serialization "generator" for `DOMElement` in domutils.js
that yields the serialization of the SVG element. This method is used by
a newly added `ReadableSVGStream` class, which can be used like any
other readable stream in Node.js.
This reduces the memory requirements. Now, it is not needed to require
the serialization to fully fit in memory.
Note: The implementation of the serializer is a state machine in ES5
since the rest of the file is also in ES5. Its functionality is
equivalent to:
```
function* serializeSVGElement(elem) {
yield '<' + elem.nodeName;
if (elem.nodeName === 'svg:svg') {
yield ' xmlns:xlink="http://www.w3.org/1999/xlink"' +
' xmlns:svg="http://www.w3.org/2000/svg"';
}
for (let i in elem.attributes) {
yield ' ' + i + '="' + xmlEncode(elem.attributes[i]) + '"';
}
yield '>';
if (elem.nodeName === 'svg:tspan' || elem.nodeName === 'svg:style') {
yield xmlEncode(elem.textContent);
} else {
for (let childNode of elem.childNodes) {
yield* serializeSVGElement(childNode);
}
}
yield '</' + elem.nodeName + '>';
}
```
- Mark the test as async, and don't swallow exceptions.
- Fix the DOMElement polyfill to behave closer to the actual getAttributeNS
method, which excludes the namespace prefix.
Do not directly export to global. Instead, export all stubs in domstubs.js and
add a method setStubs to assign all exported stubs to a namespace. Then replace
the import domstubs with an explicit call to this setStubs method. Also added
unsetStubs for undoing the changes. This is done to allow unit testing of the
SVG backend without namespace pollution.
Test case:
Using the PDF file from https://github.com/mozilla/pdf.js/issues/8534
node --max_old_space_size=200 examples/node/pdf2svg.js /tmp/FatalProcessOutOfMemory.pdf
Before this patch:
Node.js crashes due to OOM after processing 10 pages.
After this patch:
Node.js crashes due to OOM after processing 19 pages.
