- Created a new `TestWorkspace` type to lock on `AdhocWorkspace` construction. This type can't be constructed/changed in parallel.
- Updated test usages of `AdhocWorkspace` to make use of `TestWorkspace`.
- Added a `Microsoft.CodeAnalysis.Razor.Workspaces.Test.Common` project to have the `TestWorkspace` type.
#1913
- Added a Mac specific implementation of the project build change trigger. It applies to all types of project builds so we need to do a little extra filtering to ensure that we're not operating on a non-ASP.NET Core project.
- Added tests to validate that the project build event fires correctly.
#1851