Response

Response module provides constructors and utilities for managing immutable interpretations of HTTP responses.

The Response Type

A Response represents immutable and clonable HTTP Response data. It is a base element of the Response module.

import { Response } from 'fx-fetch';

type Type = Response.Response;

The Input Type

A Response.Input represents all the possible inputs that can be used to create a Response.

Concrete types that make up the Input union:

import { Response } from 'fx-fetch';

type Type = Response.Response.Input;

• globalThis.Response — vanilla JS response
• Response.Response.Parts — Object with response parts
• Response.Response — Existing Response can be used too

Constructors

Note

Making a Response manually makes sense when you need to mock responses in tests or create responses from scratch.

unsafeMake

Creates a Response from any of Response.Input. Throws an IllegalArgumentException if the provided input is invalid.

import { Response } from 'fx-fetch';
//       ┌─── Response.Response
//       ▼
const response = Response.unsafeMake({
  body: 'Hello, world!',
  status: 200,
});

make

Similar to unsafeMake, but returns an Option instead of throwing an error if the input is invalid. If the input is invalid, it returns None. If valid, it returns Some containing the Response.

import { Option } from 'effect';
import { Response } from 'fx-fetch';
//       ┌─── Option.Option<Response.Response>
//       ▼
const response = Response.make({
  body: 'Hello, world!',
  status: 200,
});

from Response.Parts

For creating a Response from an object Response.Parts use same functions make or unsafeMake.

The Parts type is super primitive. It’s basically an object with all the properties of a JS response, but with better DX. Everything except the url is optional.

import { Response } from 'fx-fetch';

const parts: Response.Response.Parts = {
  body: 'Hello, world!',
  headers: {
    'Content-Type': 'text/plain',
    'X-Custom-Header': ['CustomValue', 'AnotherValue'],
  },
  redirected: false,
  status: 200,
  statusText: 'OK',
  type: 'cors',
  url: 'https://example.com/api',
};

const response = Response.unsafeMake(parts);

Properties url and headers have flexible input types.

• url is of type Url.Input. Read more about it in Url module documentation.
• headers can be almost anything what you can imagine as headers.
  • Record of strings
  • Entries (array of tuples)
  • Map of strings
  • Same as HeadersInit in Fetch API
  • … many more…

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