Failed: Type X is part of the declarations of 2 modules: AppModule and DynamicTestModule

When writing Jasmine tests, the message above is common. The failed test looks like this:

Root Cause

AppModule already declares the component under test!

Resolve

Remove the declaration in the jasmine file; shown below:
Same test as shown above, with missing 2nd declaration.

Easy right?

JWP2019

Comments

[Mikel Hamer]

OMG THANK YOU SO MUCH