RezoHeaders

RezoHeaders is a full-featured HTTP header manager with convenience methods, proxy-based property access, and multiple serialization formats. It is used throughout Rezo for request and response headers.

Constructor

new RezoHeaders(init?: RezoHeadersInit)

Supported Init Types

Example

import { RezoHeaders } from 'rezo';

// From object
const headers = new RezoHeaders({
  'Content-Type': 'application/json',
  'Authorization': 'Bearer token123'
});

// From array of tuples
const h2 = new RezoHeaders([
  ['Accept', 'application/json'],
  ['Accept-Language', 'en-US']
]);

// From multi-value object
const h3 = new RezoHeaders({
  'Set-Cookie': ['a=1', 'b=2']
});

// Proxy access (bracket notation)
headers['x-custom'] = 'value';
console.log(headers['x-custom']); // "value"

Standard Methods (Inherited from Headers)

RezoHeaders supports all native Headers methods with the same API.

get(name)

get(name: string): string | null

set(name, value)

set(name: string, value: string): void

has(name)

has(name: string): boolean

delete(name)

delete(name: string): void

append(name, value)

Appends a value to an existing header (multi-value support).

append(name: string, value: string): void

Set-Cookie Methods

getAll(name)

Returns all values for a header that supports multiple values. Primarily used for Set-Cookie.

getAll(name: 'set-cookie' | 'Set-Cookie'): string[]

getSetCookie()

Returns all Set-Cookie header values as an array.

getSetCookie(): string[]

Example

const cookies = headers.getSetCookie();
// ["session=abc; Path=/", "theme=dark; Max-Age=3600"]

const all = headers.getAll('set-cookie');
// Same result

size

Returns the number of headers in the collection.

get size: number

const headers = new RezoHeaders({ 'Accept': 'text/html', 'Host': 'example.com' });
console.log(headers.size); // 2

Convenience Methods

setContentType(value) / getContentType()

setContentType(value: string): this
getContentType(): string | undefined

setAuthorization(value)

setAuthorization(value: string): this

setUserAgent(value) / getUserAgent()

setUserAgent(value: string): this
getUserAgent(): string | undefined

Example

const headers = new RezoHeaders();

headers
  .setContentType('application/json')
  .setAuthorization('Bearer token123')
  .setUserAgent('MyApp/1.0');

console.log(headers.getContentType()); // "application/json"
console.log(headers.getUserAgent());   // "MyApp/1.0"

Extraction Methods

getKeys()

Returns all header names as an array.

getKeys(): string[]

getValues()

Returns all header values as an array.

getValues(): string[]

Example

const headers = new RezoHeaders({ 'Accept': 'text/html', 'Host': 'example.com' });

headers.getKeys();   // ["accept", "host"]
headers.getValues(); // ["text/html", "example.com"]

Serialization Methods

toEntries()

Returns headers as an array of [key, value] tuples.

toEntries(): [string, string][]

toNative()

Creates a new native Headers instance with the same data.

toNative(): Headers

toRaw()

Returns headers as an array of [key, value] tuples, preserving multi-value headers.

toRaw(): [string, string][]

toArray()

Returns headers as an array of { key, value } objects.

toArray(): { key: string; value: string }[]

toOrderedObject(order)

Returns headers as a plain object with keys in the specified order. Keys in order come first; remaining keys are appended. Used by stealth adapters to match browser header ordering.

toOrderedObject(order: string[]): Record<string, string | string[]>

Example

const headers = new RezoHeaders({
  'Accept': 'text/html',
  'Host': 'example.com',
  'User-Agent': 'Chrome/131'
});

// Browser-like header ordering
const ordered = headers.toOrderedObject([
  'Host', 'User-Agent', 'Accept'
]);
// { host: 'example.com', 'user-agent': 'Chrome/131', accept: 'text/html' }

toObject(omit?)

Converts headers to a plain object. Optionally omits specified keys.

toObject(omit?: Array<keyof RezoHttpHeaders> | keyof RezoHttpHeaders): Record<string, string | string[]>

Example

const obj = headers.toObject();
// { accept: 'text/html', host: 'example.com' }

const filtered = headers.toObject(['host']);
// { accept: 'text/html' }

const filtered2 = headers.toObject('authorization');
// Omits the authorization header

toString()

Returns a string representation of all headers.

toString(): string

Symbol.iterator

RezoHeaders is iterable. Use for...of to iterate over [key, value] pairs.

for (const [key, value] of headers) {
  console.log(`${key}: ${value}`);
}

// Spread into array
const entries = [...headers];