Migrate rx/pure tests to strict mode, fix broken tests
Summary:
This complicates testing the migration of reactive code to coeffects,
since coeffects very much rely on correct typing. Unfortunately,
partial mode enables subtle bugs due to missing or incorrect types, thus decreasing confidence in the affected unit tests.
A few bugs have been uncovered in reactive tests, which corroborates the above. These were masked due to assume_php and partial mode.
Reviewed By: DavidSnider
Differential Revision:
D25420308
fbshipit-source-id:
b48210de4b290c0e3ff5cee3904a6e7c6543ac32