Type validations is a library for creating type-validators: augmented type-guards that perform full runtime type-validation and let TypeScript type checker know what a type may be in a certain context.
The TypeValidation<T> interface is an augmented type-guard function, that is a
function that returns
type predicate
for a given parameter.
Beside of returning type predicates, a TypeValidation<T>
- may get a rejections handler:
A second parameter: a function which would be invoked with rejections, describing why a value failed to validate. - is having a type: a
stringproperty that visually describes what the validator validates. - can be convertible to a simple (not augmented) type-guard or
booleanfunction.
Value to validate
Type: unknown
Optional callback that would be called with validation rejection reasons.
- When validation succeeds -
rejectionReasonswould not be invoked. - When validation fails -
rejectionReasonswould be invoked at least once and may be invoked multiple times.
A description of the validated type
Type: string
Returns a predicate (no second argument) for the specified validator.
Returns a type-guard predicate (no second argument) for the specified validator.
A rejection is an object describing the reason a given value failed to pass the type-validation.
A rejections handler parameter may be provided for a While the rejections handler may be called multiple times for a single value, it is guaranteed it would never be called for values that pass validation.
| Name | Type | Description |
|---|---|---|
path |
string[] |
The property names leading to the failing property (ordered inside-out). |
reason |
string |
A string describing the reason the property values failed to validate. |
propertyType |
string |
A string visualizing the type of the failing property. |
Creates type-validators for an intersections-type from a list of type-validators.
Creates type-validators for a union-type from a list of type-validators.
Given type-guard for type T, creates a type-validator for T[].
Create assertion-functions from type-validation and an error-factory.
Creates a type-validation that checks if a value is one of the specified values (using strict equality).
Creates a type-validation that only allows values that are strictly equal to the provided value.
A type-validation that checks if a value is an empty array.
A type-validation that checks if a value is an empty object.
Creates a type-validation that checks if a value is a function with a specified length.
Creates a type-validation that checks if a value is of validated type, undefined,
and optionally null.
Creates type-validation that checks if a value is an object that all its properties are validated with the provided validations.
Creates type-validator that checks that a given value is an object and that all its own-enumerable properties are of a specified type.
Creates a type-validation that checks if a value is either a specific type or an array of that type.
Creates type-validators for a union-type from a mapping between specified tag property values and validators, when the union-type is in fact a discriminated union.
Creates a type-validation that checks that an object is an array with a specific length, and has all the provided indices validated.
Creates a type-validators for a recursive type, allow limiting the recursion depth.
stringmaybeStringnumbermaybeNumberbooleanmaybeBooleannullValidationnullOrUndefinedundefinedValidationsymbolmaybeSymbolbigintmaybeBigintanyunknownnever
stringAssertionmaybeStringAssertionnumberAssertionmaybeNumberAssertionbooleanAssertionmaybeBooleanAssertionnullAssertionnullOrUndefinedAssertionundefinedAssertionsymbolAssertionmaybeSymbolAssertionbigintAssertionmaybeBigintAssertionanyAssertionunknownAssertionassert