no-implicit-any-catch
Disallow usage of the implicit
any
type in catch clauses.
TypeScript 4.0 added support for adding an explicit any
or unknown
type annotation on a catch clause variable.
By default, TypeScript will type a catch clause variable as any
, so explicitly annotating it as unknown
can add a lot of safety to your codebase.
The noImplicitAny
flag in TypeScript does not cover this for backwards compatibility reasons, however you can use useUnknownInCatchVariables
(part of strict
) instead of this rule.
Attributes
- Included in configs
- ✅ Recommended
- 🔒 Strict
- Fixable
- 🔧 Automated Fixer
- 🛠 Suggestion Fixer
- 💭 Requires type information
DEPRECATED
Rule Details
This rule requires an explicit type to be declared on a catch clause variable.
Examples of code for this rule:
- ❌ Incorrect
- ✅ Correct
try {
// ...
} catch (e) {
// ...
}
try {
// ...
} catch (e: unknown) {
// ...
}
Options
The rule accepts an options object with the following properties:
type Options = {
// if false, disallow specifying `: any` as the error type as well. See also `no-explicit-any`
allowExplicitAny: boolean;
};
const defaults = {
allowExplicitAny: false,
};
allowExplicitAny
The follow is is not considered a warning with { allowExplicitAny: true }
try {
// ...
} catch (e: any) {
// ...
}
When Not To Use It
If you are not using TypeScript 4.0 (or greater), then you will not be able to use this rule, annotations on catch clauses is not supported.