Reorganize FIAM's Resources for FIAM

[ncooke3]

FIAM was not working on SPM because the resource bundle was not generating.

There was a lot of experimentation here so I wanted to make note of some realizations/learnings:
• In order for SPM to generate a bundle for a target, the target's resources need to be in the target's Sources directory.
• The Package manifest will attempt to compile and build all targets (an issue for targets with platform-specific resources).
• FIAM only provides default UI implementations for iOS (so I've removed the blank tvOS storyboard)
• SPM generates target bundles in a single directory. So if target B is listed as a dependency of target A and both targets defines resources in their declarations, then SPM will generate a Target_B.bundle and a Target_A.bundle at the same directory level (this was against my intuition as I thought target B's bundle would be within target A's bundle since A depends on B).

Note on SPM & platform specific resources:
• There currently isn't a clear cut way to define platform specific resources. See the conversation on the Swift forums here. The workaround here is to do something similar to what was done in SPM for Analytics by creating a new target containing FIAM's iOS resources that is conditionally depended on in the primary FIAM target.

Future work:
Translating FIAM's default UI implementations from storyboards to programmatic UIKit should make this type of problem easier to fix in the future because we can use preprocessor directives (which we can't use in storyboards). Plus, programmatic UI's should be easier to maintain and update.

Fixes #7715.

[google-oss-bot]

Coverage Report

Affected SDKs

• FirebaseInAppMessaging-iOS-FirebaseInAppMessaging.framework

  SDK overall coverage changed from 43.78% (7fb172b) to 43.92% (8648a9c) by +0.14%.

  Filename	Base (7fb172b)	Head (8648a9c)	Diff
  FIRIAMDefaultDisplayImpl.m	1.60%	1.56%	-0.04%

Test Logs

• Base (7fb172b9): https://github.com/firebase/firebase-ios-sdk/actions/runs/677561295
• Head (8648a9c9): https://github.com/firebase/firebase-ios-sdk/actions/runs/719603911

[maksymmalyhin]

@ncooke3 One option that seems to be worth trying if other approaches fail:

• define separate targets with resources per platform, e.g. FirebaseInAppMessagingResources_ios, FirebaseInAppMessagingResources_tvos, etc.
• define the resource targets as conditional dependencies to FirebaseInAppMessagingTarget e.g. like here:

  firebase-ios-sdk/Package.swift

  Line 437 in a7ada99

  condition: .when(platforms: [.iOS]))],

[christibbs]

I see 🟢

I'll run tests on this today and approve if we're looking good.

[paulb777]

Nice way to eliminate complexity from the problem!

[christibbs]

We're looking good. FIAM still works on iOS and tvOS via CocoaPods. FIAM iOS works via Swift Package Manager, not for tvOS though (SPM). @ncooke3 this is expected, right?

[maksymmalyhin]

@ncooke3 Great investigation, thank you for doing it!

I may be worth creating a doc like this for the platform-specific resource in SPM with a summary, conclusions and recommendations for teams that use or plan to such resources. I can be done as a follow up for the PR.

[christibbs]

Tested this on SPM and CocoaPods for iOS and tvOS. Everything's working.

[ncooke3]

This is already imported in the header file.

[ncooke3]

Another duplicate import.

[maksymmalyhin]

LGTM 👍