Use == null comparison
Replace different nullish checks with == null
.

The == null
check is a concise expression to identify nullish values (null
and undefined
).
This refactoring replaces the following combinations of longer strict equality checks with the shorter null
comparison:
a === null || a === undefined
becomesa == null
b !== null && b !== undefined
becomesb != null
x.f(1, 2) === null || x.f(1, 2) === undefined
becomesx.f(1, 2) == null
What do I need to consider?
When two similar-looking function calls have a side effect, this refactoring can change the behavior of the code.
For example, the refactoring changes:
let a = f(1) === null || f(1) === undefined;
into
let a = f(1) == null;
If f(1)
has a side effect, it would have been called once or twice before the refactoring, and once after the refactoring.
This means that the side effect would have been called a different number of times, potentially changing the behavior.
Configuration
- Code Assist ID (for the configuration file):
use-eq-eq-null
- You can configure custom keyboard shortcuts with this code action kind:
refactor.convert.p42.use-eq-eq-null
- This code assist provides refactoring suggestions. Learn how to configure the refactoring suggestion visibility.