This PR is a reland of https://github.com/flutter/flutter/pull/181685.
The update introduced NBSP to connect time and its period(am or pm), so
some invisible breakages are expected.
Fix is added in the second
[commit](06be40e4bd).
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
Integration tests
These tests are not hermetic, and use the actual Flutter SDK. While
they don't require actual devices, they run flutter_tester to test
Dart VM and Flutter integration.
Use this command to run (from the flutter_tools directory):
../../bin/cache/dart-sdk/bin/dart test test/integration.shard
You need to have downloaded the Dart SDK in your Flutter clone for this
to work. Running ../../bin/flutter will automatically download it.
Coverage exclusion
These tests are expensive to run and do not give meaningful coverage
information for the flutter tool (since they are black-box tests that
run the tool as a subprocess, rather than being unit tests). For this
reason, they are in a separate shard when running on continuous
integration and are not run when calculating coverage.
Adding new test files
When adding a new test file make sure that it ends with _test.dart, or else it will not be run.