feat: ability to modify the LD context while dev server is running

[wichopy]

Is your feature request related to a problem? Please describe.
ld cli has some very useful features such as overriding flags and removing overrides while the dev server is running. Context can be provided at dev-server start. Something that is missing is updating the context while the dev server is running so a developer does not need to restart the server to update the context.

Describe the solution you'd like
Either:

• a modifyContext command so a developer can set the context with the dev server running
• a watchContext dev-server flag, so a developer can modify their context file and the dev server automatically picks it up in the following evaluations

Describe alternatives you've considered
overriding the default flag value for a string or number variant, but this makes test set up harder

Additional context

[mike-zorn]

You should be able to achieve something similar to the modifyContext command by calling update project. That shouldn't require a restart. Let me know if that works.

[wichopy]

This should do it! I'm curious if we are using dev server incorrectly. In some older feature flag tests we have overrides that apply at different context values without needing to constantly update the context on the dev server. Would this be bad practice ?

ie. I have a test that checks the right flag is returned for a tenant value and the right flag is returns for a region value.

[mike-zorn]

Great!

The dev server is definitely designed around having a single user (the dev) interacting with their app. As a result, context switching is gonna be a bit of a pain. I think that you might want to consider using a test data source for those tests. That lets you configure flag targeting rules local to the SDK that is being run for your tests.