no-non-null-assertion
Disallows non-null assertions using the !
postfix operator.
Rule Details
Using non-null assertions cancels the benefits of the strict null-checking mode.
Examples of code for this rule:
- ❌ Incorrect
- ✅ Correct
interface Foo {
bar?: string;
}
const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar!.includes('baz');
interface Foo {
bar?: string;
}
const foo: Foo = getFoo();
const includesBaz: boolean = foo.bar?.includes('baz') ?? false;
Options
// .eslintrc.json
{
"rules": {
"@typescript-eslint/no-non-null-assertion": "warn"
}
}
This rule is not configurable.
When Not To Use It
If you don't care about strict null-checking, then you will not need this rule.
Further Reading
Attributes
- Configs:
- ✅ Recommended
- 🔒 Strict
- 🔧 Fixable
- 💭 Requires type information