Add test coverage for test suite import prefix value

[kenzieschmoll]

Addresses a TODO from flutter/flutter#143170 (comment). The matching Flutter Tools PR is here: flutter/flutter#148244

[jakemac53]

While this could work, this is definitely not intended to be a public part of our API, it is an implementation detail only.

So from that perspective I would definitely prefer any other option. If there is no other solution that works, we could consider it.

This may not work for other integrations either - such as build_test, flutter, google3, or any other custom integrations with package:test.

[jakemac53]

cc @natebosch

[jakemac53]

Note that this also currently precludes us from adding a show main or something like that, which tbh we probably should be adding currently.

[kenzieschmoll]

Note that this also currently precludes us from adding a show main or something like that, which tbh we probably should be adding currently.

How so? import 'some_uri' as test show main; should still work fine.

[jakemac53]

How so? import 'some_uri' as test show main; should still work fine.

I believe the code I saw was looking for as test; specifically (with the semicolon). I think it also probably would get broken by any changes to whitespace.

[natebosch]

I left a comment on the other issue, but we don't currently restrict test suites to those under the package root, so I don't think you can guarantee that this URI will be useful.

[kenzieschmoll]

How so? import 'some_uri' as test show main; should still work fine.

I believe the code I saw was looking for as test; specifically (with the semicolon). I think it also probably would get broken by any changes to whitespace.

We are checking the prefix directly, so this should handle whitespace changes like adding show or hide items.

[kenzieschmoll]

Will hold off on landing this until the discussion at flutter/flutter#143170 (comment) is resolved.

[kenzieschmoll]

Closing this since this PR since this issue was resolved with a different solution than using the test import prefix: #2246