@nestjs/common/pipes/default-value.pipe.js

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

import { __decorate, __metadata } from "tslib";
import { Injectable } from '../decorators/core/injectable.decorator.js';
import { isNil, isNumber, isPlainObject } from '../utils/shared.utils.js';
/**
 * Defines the built-in DefaultValue Pipe
 *
 * A default value that is an array or a plain object is copied on every call
 * (along with the arrays and plain objects nested in it), so that a handler
 * that mutates its argument does not change it for subsequent requests. Any
 * other object (e.g., a class instance, a `Date` or a `Map`) is returned as is.
 *
 * @see [Built-in Pipes](https://docs.nestjs.com/pipes#built-in-pipes)
 *
 * @publicApi
 */
let DefaultValuePipe = class DefaultValuePipe {
    defaultValue;
    constructor(defaultValue) {
        this.defaultValue = defaultValue;
    }
    transform(value, _metadata) {
        if (isNil(value) ||
            (isNumber(value) && isNaN(value))) {
            return this.copyDefaultValue(this.defaultValue);
        }
        return value;
    }
    /**
     * Copies `value` if it is an array or a plain object, along with the arrays
     * and plain objects nested in it. `copies` maps the objects copied so far
     * to their copies, so that shared and circular references are preserved.
     */
    copyDefaultValue(value, copies) {
        const isArray = Array.isArray(value) && Object.getPrototypeOf(value) === Array.prototype;
        if (!isArray && !isPlainObject(value)) {
            return value;
        }
        copies ??= new Map();
        if (copies.has(value)) {
            return copies.get(value);
        }
        const copy = Object.assign(isArray ? [] : Object.create(Object.getPrototypeOf(value)), value);
        copies.set(value, copy);
        for (const key of Reflect.ownKeys(copy)) {
            copy[key] = this.copyDefaultValue(copy[key], copies);
        }
        return copy;
    }
};
DefaultValuePipe = __decorate([
    Injectable(),
    __metadata("design:paramtypes", [Object])
], DefaultValuePipe);
export { DefaultValuePipe };