config.ts

import { mix } from "./utils.js"

declare const global

const config = {
  // Default options
  options: {},
  // Error type
  errorType: "text",
  // Polyfills
  polyfills: {
    // fetch: null,
    // FormData: null,
    // URLSearchParams: null,
    // performance: null,
    // PerformanceObserver: null,
    // AbortController: null
  },
  polyfill(p: string, doThrow: boolean = true, instance: boolean = false, ...args: any[]) {
    const res = this.polyfills[p] ||
      (typeof self !== "undefined" ? self[p] : null) ||
      (typeof global !== "undefined" ? global[p] : null)
    if (doThrow && !res) throw new Error(p + " is not defined")
    return instance && res ? new res(...args) : res
  }
}
export type Config = typeof config

/**
 * Sets the default fetch options that will be stored internally when instantiating wretch objects.
 *
 * ```js
 * import wretch from "wretch"
 *
 * wretch.options({ headers: { "Accept": "application/json" } });
 *
 * // The fetch request is sent with both headers.
 * wretch("...", { headers: { "X-Custom": "Header" } }).get().res();
 * ```
 *
 * @param options Default options
 * @param replace If true, completely replaces the existing options instead of mixing in
 */
export function setOptions(options: object, replace = false) {
  config.options = replace ? options : mix(config.options, options)
}

/**
 * Sets the default polyfills that will be stored internally when instantiating wretch objects.
 * Useful for browserless environments like `node.js`.
 *
 * Needed for libraries like [fetch-ponyfill](https://github.com/qubyte/fetch-ponyfill).
 *
 * ```js
 * import wretch from "wretch"
 *
 * wretch.polyfills({
 *   fetch: require("node-fetch"),
 *   FormData: require("form-data"),
 *   URLSearchParams: require("url").URLSearchParams,
 * });
 *
 * // Uses the above polyfills.
 * wretch("...").get().res();
 * ```
 *
 * @param polyfills An object containing the polyfills
 * @param replace If true, replaces the current polyfills instead of mixing in
 */
export function setPolyfills(polyfills: object, replace = false) {
  config.polyfills = replace ? polyfills : mix(config.polyfills, polyfills)
}

/**
 * Sets the default method (text, json, …) used to parse the data contained in the response body in case of an HTTP error.
 * As with other static methods, it will affect wretch instances created after calling this function.
 *
 * ```js
 * import wretch from "wretch"
 *
 * wretch.errorType("json")
 *
 * wretch("http://server/which/returns/an/error/with/a/json/body")
 *   .get()
 *   .res()
 *   .catch(error => {
 *     // error[errorType] (here, json) contains the parsed body
 *     console.log(error.json)
 *   })
 * ```
 *
 * If null, defaults to "text".
 */
export function setErrorType(errorType: string) {
  config.errorType = errorType
}

export default config