refactor: migrate CupertinoPageTransitionsBuilder to cupertino folder

[rkishan516]

Changes:

• Move CupertinoPageTransitionsBuilder from material/page_transitions_theme.dart to cupertino/route.dart

part of: #172929

Pre-launch Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
• I signed the [CLA].
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is [test-exempt].
• I followed the [breaking change policy] and added [Data Driven Fixes] where supported.
• All existing and new tests are passing.

[gemini-code-assist]

Code Review

This pull request refactors the CupertinoPageTransitionsBuilder by moving it from the material library to the cupertino library. This is a logical change as the builder's implementation is based on Cupertino transition mixins. The author has correctly updated all usages within the repository, including examples and tests, by adding the necessary cupertino.dart import. The changes are clean, correct, and improve code organization. I have reviewed the code and found no issues.

[victorsanni]

Can we add a test here?

[rkishan516]

Can we add a test here?

I have added few tests.

[victorsanni]

Can we have a more non-Material oriented + Cupertino/iOS heavy documentation here? Then add a See also section that mentions MaterialPageRoute and PageTransitionsTheme etc.

[rkishan516]

Updated.

[victorsanni]

Google tests are failing due to missing cupertino imports.

[rkishan516]

Google tests are failing due to missing cupertino imports.

Will someone update those, or should we export these from material.dart(for now)?

[victorsanni]

This file will need a cupertino import if this PR lands.

Can we add a one-line dart fix here @Piinks? Considering the design libraries might be decoupling anyways. I think this PR warrants a migration guide at least.

[Piinks]

Can we add a one-line dart fix here

Hmm, I am not sure if dart fix can do this, but I've reached out to see if they can. Otherwise we should be able to add it manually.

I think a simple migration guide is a good idea. It can cover all the things we moved around wrt page transitions and explain why. :)

[rkishan516]

Hmm, I am not sure if dart fix can do this, but I've reached out to see if they can. Otherwise we should be able to add it manually.
I think a simple migration guide is a good idea. It can cover all the things we moved around wrt page transitions and explain why. :)

I will create a simple migration guide for this.

[Piinks]

I heard back from the Dart team, looks like dart fix can do this. Here is an example:

transforms:
  - title: 'Replaced by cupertino CupertinoPageTransitionsBuilder'
    date: 2023-11-09
    element:
      uris: ['material.dart']
      class: 'CupertinoPageTransitionsBuilder'
    changes:
    - kind: 'replacedBy'
      newElement:
        uris: ['cupertino.dart']
        class: 'CupertinoPageTransitionsBuilder'

[Piinks]

Thanks for the migration guide as well!

[rkishan516]

@Piinks Need your green flag for merging.

[victorsanni]

Google testing is passing now, just need to resolve some internal hitches that are preventing it from being reflected on the Github UI.

[Piinks]

LGTM! This might need a rebase to land now?

[Piinks]

Rebased 👍 I will confirm with Victor that the Google testing failures are ok before popping on the autosubmit. :)

[victorsanni]

Rebased 👍 I will confirm with Victor that the Google testing failures are ok before popping on the autosubmit. :)

Should be ok - I added the cupertino library import to relevant files (and a comment for the linter to ignore since it is currently unused).