JavaScript-like Promise implementation for asynchronous HTTP operations.

This module provides a Promise-based interface for handling asynchronous HTTP requests, wrapping Elixir's Task with familiar Promise semantics including chaining via then/3 and error handling.

Features

• Async/await pattern: Similar to JavaScript's Promise.await()
• Promise chaining: Chain operations with then/3 for sequential async operations
• Error handling: Separate success and error callbacks
• Task-based: Built on Elixir's Task.Supervisor for reliability

Basic Usage

# Simple await
{:ok, response} =
  HTTP.fetch("https://api.example.com/data")
  |> HTTP.Promise.await()

# Promise chaining
HTTP.fetch("https://api.example.com/users/1")
|> HTTP.Promise.then(&HTTP.Response.json/1)
|> HTTP.Promise.then(fn {:ok, user} ->
  IO.puts("User: " <> user["name"])
end)
|> HTTP.Promise.await()

Chaining with Error Handling

HTTP.fetch("https://api.example.com/data")
|> HTTP.Promise.then(
  fn response -> HTTP.Response.json(response) end,
  fn error -> {:error, :request_failed} end
)
|> HTTP.Promise.await()

Returning Promises from Callbacks

Callbacks in then/3 can return another Promise, enabling sequential async operations:

HTTP.fetch("https://api.example.com/posts/1")
|> HTTP.Promise.then(fn response ->
  {:ok, post} = HTTP.Response.json(response)
  # Fetch comments for this post
  HTTP.fetch("https://api.example.com/posts/1/comments")
end)
|> HTTP.Promise.then(fn comments_response ->
  HTTP.Response.json(comments_response)
end)
|> HTTP.Promise.await()