Add integration test for asset transformation feature

[andrewkolos]

In service of #143348

This adds a simple integration test for the new asset transformation feature.

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.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[andrewkolos]

Looks like using vector_graphics_compiler (as a transformer) and vector_graphics for seeing if the asset was transformed correctly by trying to render it won't work.

vector_graphics has a dependency on package http ^1.0.0, but googleapis_auth depends on ^0.13.0

While it would have been nice to use a more real-world-style example in the integration test, adding a bunch of transitive dependencies probably wasn't the right move here.

I'm considering instead using a contrived local path dependency as a transformer for this test.

[andrewkolos]

I ran this in the try pool: https://chromium-swarm.appspot.com/task?id=68c50593530ecb10

[christopherfujino]

I ran this in the try pool: https://chromium-swarm.appspot.com/task?id=68c50593530ecb10

This looks like Linux analyze?

[jmagman]

Also, since this is such a simple project, consider not adding a full integration_test project and instead making one on-the-fly as other tools integration tests do:

https://github.com/flutter/flutter/blob/master/packages/flutter_tools/test/integration.shard/test_data/basic_project.dart
https://github.com/flutter/flutter/blob/master/packages/flutter_tools/test/integration.shard/test_data/stateless_stateful_project.dart
https://github.com/flutter/flutter/blob/master/packages/flutter_tools/test/integration.shard/test_data/deferred_components_project.dart

[andrewkolos]

Hmm, this seems like a decent idea, but perhaps there is value is keeping the project on repo—we could use it as part of the documentation for the feature on flutter.dev. For example we do this for flavors:

For examples of build flavors for iOS, macOS, and Android, check out the integration test samples in the Flutter repo.

I imagine myself writing a "how to write your own asset-transforming package" section the flutter.dev documentation for the feature, and users might appreciate being able to see a complete example (and not just a snippet). Let me know what you think.

[christopherfujino]

Maybe we should add this to https://github.com/flutter/samples.

There is a baseline cost to every flutter project that we keep in the flutter/flutter repo (both pubspec deps and also maintaining the platform-specific directories.

[christopherfujino]

If you go with generating this on the fly, I would recommend not using dart create to create the dart transformer project, but instead just programmatically creating the files you need, so that upstream changes to the dart create ... output won't break the flutter/flutter tree.

[andrewkolos]

TIL of the existence of flutter/samples.

I'll 1) proceed with Jenn's suggestion and 2) consider adding a sample to flutter/samples when writing the flutter.dev documentation.

[andrewkolos]

Addressed in create test project on-the-fly instead of having it in-repo

[jmagman]

Hmm, this seems like a decent idea, but perhaps there is value is keeping the project on repo—we could use it as part of the documentation for the feature on flutter.dev. For example we do this for flavors:

For examples of build flavors for iOS, macOS, and Android, check out the integration test samples in the Flutter repo.

I imagine myself writing a "how to write your own asset-transforming package" section the flutter.dev documentation for the feature, and users might appreciate being able to see a complete example (and not just a snippet). Let me know what you think.

Have you reached out to DevRel? They could help with messaging this. In any case, at the point you need a complete example for documentation, and not integration tests, I agree that samples would be a better spot for it.

[andrewkolos]

Have you reached out to DevRel? They could help with messaging this.

Good idea

[christopherfujino]

@andrewkolos what's the status on this PR?

[andrewkolos]

@andrewkolos what's the status on this PR?

@christopherfujino, IIRC all comments have been addressed and this is ready for review.

[christopherfujino]

LGTM