(iOS) Dark mode splashscreen storyboard images

[terreng]

This is my first pr so please don't burn me at the stake.

Platforms affected

iOS

Motivation and Context

I wanted to include a dark mode variant of my app's splash screen, but found that Cordova did not yet support this feature. It turns out that it only took a few lines of code, so I figured I'd share it here.

I found this related issue: apache/cordova-plugin-splashscreen#246. It turns out that no changes to the splashscreen plugin are necessary to make it happen.

Description

This enables dark mode storyboard images by allowing you to specify splash images based on appearance (dark or light). It checks for ~dark or ~light suffixes in splash images. If neither is found, they're used as the default. It then adds the variants to Contents.json, and the rest is handled by iOS. Example config.xml:

<splash src="res/screen/ios/Default@3x~iphone~comany.png" />
<splash src="res/screen/ios/Default@3x~iphone~comany~dark.png" />

This pr only adds support for iOS.

Testing

I've tested these changes on an iPhone and everything appears to work as intended. I've updated existing tests and added new ones as appropriate, and all tests pass.

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

Documentation would need to change over at https://github.com/apache/cordova-plugin-splashscreen/blob/master/README.md.

Thank you.

[NiklasMerz]

@terreng Thank you for your first PR 🥇 This is a great feature. Please check the Travis log, if you can turn the tests green, review is much easier.

Looks like some tests need to be changed and/or new tests are needed.

[breautek]

Thank you for your PR. Just a couple notes, not exactly related to this PR, but when making PRs in general.

I haven't run any tests

You can run local tests on your machine by running npm test. This will help catch some problems (such as your eslint error 😜 )

I also noticed that you made changes in your fork's master branch for your PR. I would recommend always creating a new branch for your PRs to keep your master branch clean. This isn't a problem right now, but could be later. If you add more commits to your master (maybe for a different PR) those commits will end up in this PR as well and that would not be very desirable.

Regarding this PR specifically, I think everything looks good and I'm happy you considered making specifying the appearance optional, which also helps maintain backwards compatibility. As soon as the checks turn green I'll give my 👍

[terreng]

Alright, I've updated the failed tests and added three new ones.

[codecov-io]

Codecov Report

Merging #808 into master will increase coverage by 0.08%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #808      +/-   ##
==========================================
+ Coverage    74.2%   74.28%   +0.08%     
==========================================
  Files          13       13              
  Lines        1849     1855       +6     
==========================================
+ Hits         1372     1378       +6     
  Misses        477      477

Impacted Files	Coverage Δ
bin/templates/scripts/cordova/lib/prepare.js	82.28% <100%> (+0.23%)	⬆️

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[NiklasMerz]

I think documentation how to use this feature should be part of this PR, too.

[terreng]

Documentation would have to change for cordova-plugin-splashscreen which isn't a part of this repo.

[NiklasMerz]

Good point. I got confused that the code is part of cordova-ios and not the plugin.

[dpogue]

Did some tests with this and it all looks to work as intended 👍

[erisu]

Code Changes LGTM