isStringConstraint()
isStringConstraint(
schema):schema is StringConstraint
Type guard for StringConstraint. Checks that the schema is a string type and has constraint methods.
Parameters
schema: GenericSchema
The schema to check
Returns: schema is StringConstraint
True if the schema is a StringConstraint with constraint methods
Since
2.0.0
Example
const schema = string().minLength(5);
if (isStringConstraint(schema)) {
// schema is narrowed to StringConstraint
schema.maxLength(10); // constraint methods available
}