Update to Babel 8

[nicolo-ribaudo]

I diffed the Babel 7 and Babel 8 builds for generic, mozcentral, and lib. They are almost identical.

• There re no differences in mozcentral
• Both in generic and lib, when we inline the .ftl strings in

  pdf.js/web/genericl10n.js

  Lines 135 to 141 in 7e7ed1b

  	const text =
  	typeof PDFJSDev === "undefined"
  	? await fetchData(
  	new URL("../l10n/en-US/viewer.ftl", window.location.href),
  	/* type = */ "text"
  	)
  	: PDFJSDev.eval("DEFAULT_FTL");

  , Babel 8 emits non-ASCII characters by default rather than forcefully escaping them (e.g. Babel 8 preserves ’, while Babel 7 converts it to \u2019).

I had to inline the Babel plugin that injects the header comment in the lib build, as it didn't support Babel 7. I opened a PR (Shopify/babel-plugin-add-header-comment#9), but it's so simple that it's probably not worth waiting.

The inlined plugin also keeps the copyright notice, which I believe should be there while it wasn't there before:

  -/**
  -* 
  -* Licensed under the Apache License, Version 2.0 (the "License");
  -* you may not use this file except in compliance with the License.
  -* You may obtain a copy of the License at
  -* 
  -*     http://www.apache.org/licenses/LICENSE-2.0
  -* 
  -* Unless required by applicable law or agreed to in writing, software
  -* distributed under the License is distributed on an "AS IS" BASIS,
  -* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  -* See the License for the specific language governing permissions and
  -* limitations under the License.
  -**/
  +/* Copyright 2024 Mozilla Foundation
  + *
  + * Licensed under the Apache License, Version 2.0 (the "License");
  + * you may not use this file except in compliance with the License.
  + * You may obtain a copy of the License at
  + *
  + *     http://www.apache.org/licenses/LICENSE-2.0
  + *
  + * Unless required by applicable law or agreed to in writing, software
  + * distributed under the License is distributed on an "AS IS" BASIS,
  + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  + * See the License for the specific language governing permissions and
  + * limitations under the License.
  + */

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.82%. Comparing base (25eae30) to head (b9609d0).

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21475      +/-   ##
==========================================
+ Coverage   89.80%   89.82%   +0.01%     
==========================================
  Files         261      261              
  Lines       66346    66346              
==========================================
+ Hits        59581    59592      +11     
+ Misses       6765     6754      -11     

Flag	Coverage Δ
browsertest	66.62% <ø> (+<0.01%)	⬆️
fonttest	9.03% <ø> (ø)
integrationtest	68.95% <ø> (-0.10%)	⬇️
unittest	57.28% <ø> (+<0.01%)	⬆️
unittestcli	56.23% <ø> (-0.02%)	⬇️

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[Snuffleupagus]

I diffed the Babel 7 and Babel 8 builds for generic, mozcentral, and lib. They are almost identical.

Does that testing include the gulp generic-legacy and gulp lib-legacy builds, given the core-js changes in this patch?

[timvandermeij]

Looks good to me, with the question above addressed. Thank you for helping out with this!

[nicolo-ribaudo]

Just checked the two legacy builds, and the changes are the same as what described in the PR description.

Note that the core-js changes are not in what is actually polyfilled, but just that now we call babel-plugin-polyfill-corejs3 directly (in Babel 7, @babel/preset-env would call babel-plugin-polyfill-corejs3 internally).

[timvandermeij]

r=me, with passing browser tests. Thank you!

[timvandermeij]

/botio browsertest

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

Command cmd_browsertest from @timvandermeij received. Current queue size: 0

Live output at: http://54.193.163.58:8877/cadf627c878fa9f/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_browsertest from @timvandermeij received. Current queue size: 0

Live output at: http://54.241.84.105:8877/cdd40e91b61e190/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.241.84.105:8877/cdd40e91b61e190/output.txt

Total script time: 18.11 mins

• Regression tests: Passed

[moz-tools-bot]

From: Bot.io (Windows)

---

Failed

Full output at http://54.193.163.58:8877/cadf627c878fa9f/output.txt

Total script time: 26.26 mins

• Regression tests: FAILED

  errors: 6

Image differences available at: http://54.193.163.58:8877/cadf627c878fa9f/reftest-analyzer.html#web=eq.log

[nicolo-ribaudo]

/botio browsertest-windows

[moz-tools-bot]

From: Bot.io (Windows)

---

Received

Command cmd_browsertest from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.193.163.58:8877/67bbc5d509c42a2/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Received

Command cmd_browsertest from @nicolo-ribaudo received. Current queue size: 0

Live output at: http://54.241.84.105:8877/4bd101b6afd453e/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.241.84.105:8877/4bd101b6afd453e/output.txt

Total script time: 18.43 mins

• Regression tests: Passed

[moz-tools-bot]

From: Bot.io (Windows)

---

Success

Full output at http://54.193.163.58:8877/67bbc5d509c42a2/output.txt

Total script time: 25.97 mins

• Regression tests: Passed