[path_provider] added android support for getDownloadsDirectory

[zopagaduanjr]

Followed step 3. of this approach flutter/plugins#4559 (review)

Fixes flutter/flutter#93198

originally from #4167 , but I renamed the branch hence it was closed

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 relevant style guides and ran the auto-formatter. (Unlike the flutter/flutter repo, the flutter/packages repo does use dart format.)
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I listed at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style.
• 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.
• All existing and new tests are passing.

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

[stuartmorgan-g]

This comment is still unaddressed (both the missing test, and the implementation bug that the missing test would demonstrate).

[zopagaduanjr]

this one I've updated to catch the stateError scenario when externalStoragePaths returns empty list.

[zopagaduanjr]

can check this one if its going in the right direction? I'm trying to add a case for the null externalStoragePaths, but if I override it to empty list then it will affect other tests

[camsim99]

You'll either have to modify kExternalStoragePaths and set it back or override _Api or TestPathProviderApi with the desired behavior and set your test to use that implementation like here.

[zopagaduanjr]

I've updated the null test

[camsim99]

This approach seems okay to me but perhaps you can move this test to a different group and set up the TestPathProviderApi with TestPathProviderApi.setup(_ApiNull()) just for that group of tests, so that it doesn't conflict with any tests in this group?

[stuartmorgan-g]

Sorry, I had an answer to the original question that I didn't realize I'd never actually published, and was still Pending. It would be much simpler to make the test implementation return configurable values, rather than have two different implementations and test groups.

[zopagaduanjr]

I've updated the getDownloads test to use mockito, so we can configure values for normal path and null path

[camsim99]

I believe Stuart was suggesting making _Api return a configurable value (i.e. modifying kExternalStoragePaths) versus mocking TestPathProviderApi, but please correct me if I'm wrong.

[stuartmorgan-g]

Yes, I was suggesting making the values returned by _Api configurable rather than hard-coded constants. Usually we do that by making the return values public fields of the fake implementation.

I'm okay with mockito instead (although I think it's overkill here), but not with having two different ways of structuring these tests; if you really want to use mockito then all of the tests need to be rewritten to use mockito and _Api removed.

[camsim99]

I think this change is causing the test failures since getDownloadsPath() doesn't need to be implemented on the native side.

[zopagaduanjr]

got it, i have removed getDownloadsPath

[camsim99]

@stuartmorgan I assume these should be removed before being merged?

[camsim99]

I believe Stuart was suggesting making _Api return a configurable value (i.e. modifying kExternalStoragePaths) versus mocking TestPathProviderApi, but please correct me if I'm wrong.

[reidbaker]

@zopagaduanjr thank you for your contribution this appears to have been taken over by #4708 so I am going to close this PR to remove it from our queue.