Fail with specific error for null runnerSuite (#1245)

See https://github.com/flutter/flutter/issues/56457

If we get a null `runnerSuite` the attempt to read the `environment`
file will fail, resulting in a confusing error and stack trace. We can't
reproduce this locally so it isn't clear where the null may be coming
from.

Add additional information to the error thrown to try to narrow down the
places we need to search for a root cause.
7 files changed
tree: 916175f10e97c5ebec53b42b82403c205295c85b
  1. pkgs/
  2. tool/
  3. .gitignore
  4. .travis.yml
  5. analysis_options.yaml
  6. CONTRIBUTING.md
  7. mono_repo.yaml
  8. README.md
README.md

Test Mono Repository

This repository contains packages for writing and running Dart tests.

test

A full featured packaged for writing and running Dart tests on various platforms, e.g. VM, Chrome, Node etc.

test_api

A minimal package for writing tests. This package is used by package:test and package:test_core.

test_core

A minimal package for writing and running tests. It also contains extensions for implementing a custom test runner. This package is used by package:test.