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OriginTS

guard

guard<T>(source, predicate, reason?): GuardSpec<T>

Defined in: extract/spec.ts:498

Validate a successfully extracted value against a predicate. Fails with ‘constraint’ kind if the predicate returns false.

Type Parameters

Section titled “Type Parameters”

T

Section titled “T”

T extends Spec

Parameters

Section titled “Parameters”

source

Section titled “source”

T

predicate

Section titled “predicate”

(value) => boolean

reason?

Section titled “reason?”

string

Returns

Section titled “Returns”

GuardSpec<T>

Example

Section titled “Example”
guard(
  $.get('age').number(),
  v => (v as number) > 0,
  'Age must be positive'
)