The field is no longer used by pub and triggers a warning on publish.

Remove TODO comments waiting for things that will never change or that
we don't intend to take action on.

- https://github.com/dart-lang/sdk/issues/22977 is closed as not
  planned.
- Dart 2 does not support importing `dart:io` in cross platform code.
- Setting the exit code is not supported on web.
- We plan on keeping `executable.dart` under lib to allow reuse from
  other packages internally.
- We don't plan on trying to support `spawnHybridUri` outside of the
  test runner.
- `executable.main` is now declared to return a `Future`.
- We don't intend to take a dependency on `json_schema`.

Flutter pins package dependencies, including all transitive dependencies.

Because test_api depends on pedantic, Flutter pins that dependency.

However, pedantic is only depended on for the `unawaited` function, which is a one-line piece of code.

This will enable resolution of https://github.com/flutter/flutter/issues/48246 without requiring Flutter to unpin its dependencies, and with a very small overhead on test_api to not re-import pedantic :)  This helps downstream consumers who want to depend on the package for the actual analysis options files.

Also related: https://github.com/dart-lang/pedantic/issues/46

Prepare for a potential breaking change in `package:boolean_selector`.
Currently the `evaluate` method takes an argument which is either an
`Iterable<String>` or a `bool Function(String)` which matches the
`.toSet()contains` tearoff on that Iterable. We might tighten that to
always take a `bool Function(String)` since the tearoff is easy to
handle at the calling side.

- always_declare_return_types
- annotate_overrides
- await_only_futures
- omit_local_variable_types
- prefer_collection_literals
- prefer_conditional_assignment
- prefer_final_fields
- prefer_for_elements_to_map_fromiterable
- prefer_if_null_operators
- prefer_spread_collections
- unnecessary_this
- use_function_type_syntax_for_parameters

Bump min SDK to 2.3.0 everywhere to allow using spreads in collection
literals.

Skip an already failing test

This lint may soon be enforced in `package:pedantic`.

If a test times out at the default timeout, point to the docs for
changing timeouts in the error message.

* Extend synthetic test timeout

* better solo

Open to feedback on this. Here's how it works at the moment:

There's a new `--coverage` option that you can use to specify the output directory for your coverage. It will create a new output directory if one doesn't already exist.

The tests are run through the engine, and then get spit out to a coverage helper function. That coverage helper function:
**A)** Checks if it's a VM suite
**B)** Gathers coverage if it is
**C)** Outputs coverage to `${suite path}.vm.json`

So, for example, when I run:
```bash
pub run test --coverage hello_world test/vm/simple_repo_test.dart
```

A new file gets added at `hello_world/test/vm/simple_repo_test.dart.vm.json` with the coverage results!

Mark internal packages as deprecated to hopefully prevent accidental use.

- Remove `removeAllOutstandingCallbacks` method. This never had any
  usage outside of `scheduled_test` which has been deprecated for a long
  time.
- Change some bare `Future` to `Future<void>`.
- Move and rename `OutstandingCallbackCounter` class - the
  implementation has no ties to the concept of callbacks, but that is
  how it is used.
- Use the modern syntax for function typed arguments.
- Add generics to `unclosable` to void throwing away potentially useful
  type information.

A recent change to the Dart SDK updated `HttpClientResponse`
to implement `Stream<Uint8List>` rather than implementing
`Stream<List<int>>`.

This forwards-compatible chnage updates calls to
`Stream.transform(StreamTransformer)` to instead call the
functionally equivalent `StreamTransformer.bind(Stream)`
API, which puts the stream in a covariant position and
thus causes the SDK change to be non-breaking.

https://github.com/dart-lang/sdk/issues/36900

In some environments the state change events and the "test complete" event are sent over a stream that does not guarantee ordering (e.g. as independent HTTP requests when using package:sse).
Without this change, such tests will fail intermittently, when the "test complete" event happens to be delivered before the state change event.

Allows using `expectAsync*` to wrap callbacks in context where they are
called with a `try/catch` without changing visible behavior.

Closes https://github.com/dart-lang/test/issues/1032

Run analyzer (at a minimum) across all packages at their oldest supported SDK

Added `backend.dart` files to `test_core` and `test_api` that expose some new classes for use with the new `parseMetadata` function.

- Don't surround versions with quotes unless they have a space.
- Remove the unnecessary lower bound for packages where the current
  lower bound is not resolvable due to SDK constraints.
- Change single quotes to double quotes since they are preferred in
  yaml.
- Remove version constraints from `test_api` to `test` and `test_core`
  since we will always have path overrides to those packages.

Version `1.7.0` adds the import so it's the minimum version required.
Allow versions through `2.x` since the breaking change will be to change
the import which will now be satisfied.

We have removed most of the special handling around
`IsolateSpawnException` so ti shouldn't matter if the exposed exception
implements that interface. On the web, for the `spawnHybridUri` or
`spawnHybridCode` case the web code shouldn't be able to see the type to
test for it anyway.

After splitting the package the file was copied to some of the package
but missing from the `test_core` package. Move it back up the directory
structure so it is picked up for all sub-packages.

Fix lints that were not caught in `test_core` while this was missing.

* prep for release

- Fix some new implicit cast warnings.
- Adjust expectations for new source_span output.

In version `1.5.0` of `source_span` the output for multi-line spans was
updated to output the content and highlight a section with lines on the
left instead of the old `^^^^^` format. Update the expectations
accordingly to expect that a bit of the multi-line content is printed.

Fixes https://github.com/dart-lang/test/issues/943

Also adjust the platform-specific-configuration links.