Rather than assigning it manually in every extending class, we can utilize the fact that the `AnnotationType`-entries are simply the upper-case version of the `/Subtype` (when it exists) in the Annotation dictionary.
When checking the code coverage report, it was noticed that the line numbers were off.
It was due to the fact that the files used for coverage were the transpiled ones,
when the ones used by Codecov were the original ones.
So this patches adds the source maps to the transpiled files, and also updates
the license header in the original files in using a babel plugin in order
to make sure the line numbers are correct.
As a side effect of this work, it's now possible to have the correct line
numbers in the stack traces when running tests with the transpiled files.
It's a first step to add code coverage.
In order to get the code coverage report locally, you can run the following command:
```bash
npx gulp unittestcli --coverage
```
The code coverage report will be generated in the `./build/coverage` directory.
And the report can be consulted by opening:
http://localhost:8888/build/coverage/index.html
A GitHub workflow has also been added to run the unit tests with code coverage
on each push and pull request. The report will be uploaded to Codecov.
This leads to slightly shorter code[1] when initializing classes, and in some cases we can even remove the constructors, which shouldn't hurt; see https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-class-fields.md
It's probably possible to also change a lot of these class fields to private ones[2], however it's often difficult to tell at a glance if that's safe hence this patch only does this for the `PDFRenderingQueue`.
---
[1] This reduces the size of the `gulp mozcentral` output by 999 bytes, for a mostly mechanical code change.
[2] That sort of re-factoring should generally be done separately, on a class-by-class basis, to reduce the risk of regressions.
While we don't dispatch the actual range request after PR 10694 we still parse the returned data, which ends up being an *empty* `ArrayBuffer` and thus cannot affect the `ChunkedStream.prototype._loadedChunks` property.
Given that no actual data arrived, it's thus pointless[1] to invoke the `ChunkedStreamManager.prototype.onReceiveData` method in this case (and it also avoids sending effectively duplicate "DocProgress" messages).
---
[1] With the *possible* exception of `disableAutoFetch === false` being set, see f24768d7b4/src/core/chunked_stream.js (L499-L517) however that never happens when streaming is being used; note f24768d7b4/src/core/worker.js (L237-L238)
In all cases where we currently use `Response.prototype.arrayBuffer()` the result is immediately wrapped in a `Uint8Array`, which can be avoided by instead using the newer `Response.prototype.bytes()` method; see https://developer.mozilla.org/en-US/docs/Web/API/Response/bytes
