Disallow non-null assertion in locations that may be confusing (no-confusing-non-null-assertion
)
Rule Details
Using a non-null assertion (!
) next to an assign or equals check (=
or ==
or ===
) creates code that is confusing as it looks similar to a not equals check (!=
!==
).
a! == b; // a non-null assertions(`!`) and an equals test(`==`)
a !== b; // not equals test(`!==`)
a! === b; // a non-null assertions(`!`) and an triple equals test(`===`)
- โ Incorrect
- โ Correct
interface Foo {
bar?: string;
num?: number;
}
const foo: Foo = getFoo();
const isEqualsBar = foo.bar! == 'hello';
const isEqualsNum = 1 + foo.num! == 2;
interface Foo {
bar?: string;
num?: number;
}
const foo: Foo = getFoo();
const isEqualsBar = foo.bar == 'hello';
const isEqualsNum = (1 + foo.num!) == 2;
When Not To Use It
If you don't care about this confusion, then you will not need this rule.
Further Reading
Attributes
- โ Recommended
- ๐ง Fixable
- ๐ญ Requires type information