[iOS] specify minimum os version for native asset frameworks

[knopp]

Fixes #148501

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[knopp]

@dcharkes is the plist file tested anywhere? Also the approach here is a bit ugly, the issue is that the plist key is different for macOS and iOS, and also as far as I can tell it is not mandatory.

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[dcharkes]

I believe this value should come from somewhere.

(Also this value should be passed into the BuildConfig so that the build hook can fail if it cannot produce a dylib with the right iOS version (dart-lang/native#1133). This can be done in a separate PR though.)

[dcharkes]

Do we have the minimum iOS version that the app we're building is targeting somewhere? See the code that does the same for minimum android version: #148044 (comment)

[dcharkes]

@dcharkes is the plist file tested anywhere?

No. You could add it here:

flutter/packages/flutter_tools/test/integration.shard/isolated/native_assets_test.dart

Lines 314 to 348 in 6b38361

	void expectDylibIsBundledMacOS(Directory appDirectory, String buildMode) {
	final Directory appBundle = appDirectory.childDirectory('build/$hostOs/Build/Products/${buildMode.upperCaseFirst()}/$exampleAppName.app');
	expect(appBundle, exists);
	final Directory frameworksFolder =
	appBundle.childDirectory('Contents/Frameworks');
	expect(frameworksFolder, exists);
	// MyFramework.framework/
	// MyFramework -> Versions/Current/MyFramework
	// Resources -> Versions/Current/Resources
	// Versions/
	// A/
	// MyFramework
	// Resources/
	// Info.plist
	// Current -> A
	const String frameworkName = packageName;
	final Directory frameworkDir =
	frameworksFolder.childDirectory('$frameworkName.framework');
	final Directory versionsDir = frameworkDir.childDirectory('Versions');
	final Directory versionADir = versionsDir.childDirectory('A');
	final Directory resourcesDir = versionADir.childDirectory('Resources');
	expect(resourcesDir, exists);
	final File dylibFile = versionADir.childFile(frameworkName);
	expect(dylibFile, exists);
	final Link currentLink = versionsDir.childLink('Current');
	expect(currentLink, exists);
	expect(currentLink.resolveSymbolicLinksSync(), versionADir.path);
	final Link resourcesLink = frameworkDir.childLink('Resources');
	expect(resourcesLink, exists);
	expect(resourcesLink.resolveSymbolicLinksSync(), resourcesDir.path);
	final Link dylibLink = frameworkDir.childLink(frameworkName);
	expect(dylibLink, exists);
	expect(dylibLink.resolveSymbolicLinksSync(), dylibFile.path);
	}

[knopp]

Do we have the minimum iOS version that the app we're building is targeting somewhere? See the code that does the same for minimum android version: #148044 (comment)

I think this is right now hardcoded to 12.0 for App.framework inside AppFrameworkInfo.plist. There is also IPHONEOS_DEPLOYMENT_TARGET set by xcode during build that contains project deployment target. But I think the plugin should be able to specify own deployment target, that seems like the cleanest way.

[dcharkes]

I think this is right now hardcoded to 12.0 for App.framework inside AppFrameworkInfo.plist. There is also IPHONEOS_DEPLOYMENT_TARGET set by xcode during build that contains project deployment target. But I think the plugin should be able to specify own deployment target, that seems like the cleanest way.

cc @vashworth and @jmagman What is the interplay between XCode and a Flutter app on the minimal iOS version?

[jmagman]

What is the interplay between XCode and a Flutter app on the minimal iOS version?

The target version is the minimum support by latest Xcode. https://flutter.dev/go/match-xcode-deployment-range

This document proposes that Flutter’s supported deployment platform versions be updated when Xcode is released annually to match its deployment versions. Versions lower than the Xcode range will become unsupported.

Right now it's set in the tool in a bunch of places, see #140823 for the last time we had to bump it (note the changes in dev and example weren't manually updated, those are automatically migrated example/test apps).

@vashworth filed #145104 to make this settable in fewer places.

[dcharkes]

Thanks @jmagman!

Then I'm fine landing as is once we added a test. And maybe leave a comment on #145104 so that it doesn't get forgotten.

[knopp]

@dcharkes, I added test and a TODO to wire things once hook can specify deployment target. There is another issue - the bundle identifier must not contain underscores, we should replace them by - probably. Should that be part of this PR or should I make separate PR for it?

[knopp]

Sanitizing the bundle identifier seems like a tiny change, I added it to this PR.

[knopp]

@dcharkes, just a heads up, with this PR we have been able to get an app uploaded through AppStore connect.

[dcharkes]

Thanks so much for triaging and supplying a PR @knopp! ❤️ LGTM! 🚀