@nestjs/common/interfaces/features/pipe-transform.interface.d.ts

Nest - modern, fast, powerful node.js web framework (@common)

import { Type } from '../type.interface';
import { Paramtype } from './paramtype.interface';
export type Transform<T = any> = (value: T, metadata: ArgumentMetadata) => any;
/**
 * Interface describing a pipe implementation's `transform()` method metadata argument.
 *
 * @see [Pipes](https://docs.nestjs.com/pipes)
 *
 * @publicApi
 */
export interface ArgumentMetadata {
    /**
     * Indicates whether argument is a body, query, param, or custom parameter
     */
    readonly type: Paramtype;
    /**
     * Underlying base type (e.g., `String`) of the parameter, based on the type
     * definition in the route handler.
     */
    readonly metatype?: Type<any> | undefined;
    /**
     * String passed as an argument to the decorator.
     * Example: `@Body('userId')` would yield `userId`
     */
    readonly data?: string | undefined;
}
/**
 * Interface describing implementation of a pipe.
 *
 * @see [Pipes](https://docs.nestjs.com/pipes)
 *
 * @publicApi
 */
export interface PipeTransform<T = any, R = any> {
    /**
     * Method to implement a custom pipe.  Called with two parameters
     *
     * @param value argument before it is received by route handler method
     * @param metadata contains metadata about the value
     */
    transform(value: T, metadata: ArgumentMetadata): R;
}