http headers combinator

http-headers.util.js

/**
 * @typedef {(
 *   "text/plain" |
 *   "text/html" |
 *   "text/css" |
 *   "text/javascript" |
 *   "application/javascript" |
 *   "application/json" |
 *   "application/xml" |
 *   "application/x-www-form-urlencoded" |
 *   "application/octet-stream" |
 *   "multipart/form-data" |
 *   "image/jpeg" |
 *   "image/png" |
 *   "image/gif" |
 *   "image/webp" |
 *   "image/svg+xml" |
 *   "audio/mpeg" |
 *   "video/mp4" |
 *   "video/webm" |
 *   "font/woff" |
 *   "font/woff2" |
 *   "font/ttf" |
 *   "application/pdf" |
 *   "application/zip" |
 *   "application/vnd.api+json" |
 *   string
 * )} ContentType
 */

/**
 * Returns an object with the `Content-Type` header.
 * @param {ContentType} type
 * @returns {{ "Content-Type": string }}
 */
export function setContentType(type) {
  return { "Content-Type": type };
}

/**
 * Returns an object with the `Authorization` header.
 * @param {string} token
 * @returns {{ Authorization: string }}
 */
export function setAuthorization(token) {
  return { Authorization: `Bearer ${token}` };
}

/**
 * Returns an object with the `Accept-Language` header.
 * @param {string} lang
 * @returns {{ "Accept-Language": string }}
 */
export function setAcceptLanguage(lang) {
  return { "Accept-Language": lang };
}

/**
 * Merges multiple header objects into one.
 *
 * Useful for combining results of `setAuthorization`, `setContentType`, etc.
 *
 * @example
 * const headers = mergeHeaders(
 *   setAuthorization("abc"),
 *   setContentType("application/json"),
 *   { "X-Custom": "test" }
 * );
 *
 * // {
 * //   Authorization: "Bearer abc",
 * //   "Content-Type": "application/json",
 * //   "X-Custom": "test"
 * // }
 *
 * @param {...Object<string, string>} parts
 * @returns {Object<string, string>}
 */
export function mergeHeaders(...parts) {
  return Object.assign({}, ...parts);
}

http-headers.util.ts

/**
 * List of supported Content-Type values.
 */
export type ContentType =
  | "text/plain"
  | "text/html"
  | "text/css"
  | "text/javascript"
  | "application/javascript"
  | "application/json"
  | "application/xml"
  | "application/x-www-form-urlencoded"
  | "application/octet-stream"
  | "multipart/form-data"
  | "image/jpeg"
  | "image/png"
  | "image/gif"
  | "image/webp"
  | "image/svg+xml"
  | "audio/mpeg"
  | "video/mp4"
  | "video/webm"
  | "font/woff"
  | "font/woff2"
  | "font/ttf"
  | "application/pdf"
  | "application/zip"
  | "application/vnd.api+json";

/**
 * Returns a header object containing the given Content-Type.
 *
 * @param {ContentType} type - The content type to use.
 * @returns {Record<string, string>} A headers object with the Content-Type set.
 */
export function setContentType(type: ContentType): Record<string, string> {
  return { "Content-Type": type };
}

/**
 * Returns a header object with a Bearer Authorization token.
 *
 * @param {string} token - The bearer token to use.
 * @returns {Record<string, string>} A headers object with the Authorization set.
 */
export function setAuthorization(token: string): Record<string, string> {
  return { Authorization: `Bearer ${token}` };
}

/**
 * Returns a header object with the specified Accept-Language.
 *
 * @param {string} lang - The language code to use (e.g., "en-US").
 * @returns {Record<string, string>} A headers object with Accept-Language set.
 */
export function setAcceptLanguage(lang: string): Record<string, string> {
  return { "Accept-Language": lang };
}

/**
 * Combines multiple header objects into a single headers object.
 *
 * This function is useful for merging the results of helper functions like
 * `setContentType`, `setAuthorization`, `setAcceptLanguage`, and other
 * custom headers into one object that can be passed to Axios or fetch requests.
 *
 * @example
 * const headers = mergeHeaders(
 *   setAuthorization(token),
 *   setContentType("application/json"),
 *   { "X-Custom-Header": "value" }
 * );
 *
 * // Result:
 * // {
 * //   "Authorization": "Bearer <token>",
 * //   "Content-Type": "application/json",
 * //   "X-Custom-Header": "value"
 * // }
 *
 * @param {...Record<string, string>} parts - One or more header objects to merge.
 * @returns {Record<string, string>} A single merged headers object.
 */
export function mergeHeaders(
  ...parts: Array<Record<string, string>>
): Record<string, string> {
  return Object.assign({}, ...parts);
}