Schema.raw

Description

Creates a custom validator from scratch. You provide your own validation logic as a callback, and the schema uses that logic to determine whether a value is valid. This is the most flexible validator and serves as the foundation for building specialized validators.

Usage

import * as Schema from "@bytelab.studio/schemify";

// Extends RawOptions
export interface IsEvenOptions extends Schema.RawOptions {
    // define options here...
    // all options must be optional
}

export function isEven<Options extends IsEvenOptions>(options?: Options): Schema.ValidatorFunction<Options, boolean> {
    // Initialize options
    options = options ?? {} as Options

    return Schema.raw<Options>((value: NonNullable<unknown>, context: Schema.ValidatorContext) => {
        // Respect flags of the RawOptions interface...

        if (typeof value !== "number") {
            throw new Schema.SchemaError("Expected a number", context);
        }

        return value % 2 == 0;
    }, options);
}

// Mark the validator as a validator.
isEven[Schema.isValidatorSymbol] = true;

Notes

• The callback functions receive:
  • value: The raw value to validate. Should always consider as unknown type that is not null or undefined.
  • context: The validator context of the current validation progression e.g., validation path in nested objects.
• Always throw a SchemaError if the value is invalid. Otherwise, the Error will be misinterpreted by other validators.
• Always return a value on success validation of in the generic defined type.

Options

Options	Type	Default	Description
nullable	boolean	undefined	Whether null is accepted as a valid value.
optional	boolean	undefined	Whether undefined is accepted as a valid value.

Definition

export interface RawOptions {
    nullable?: boolean;
    optional?: boolean;
}