HTTPower.Adapter.Tesla (HTTPower v0.16.0)

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Tesla adapter for HTTPower.

This adapter allows HTTPower to work with existing Tesla clients, enabling you to add HTTPower's production features (circuit breakers, rate limiting, retry logic, PCI logging) on top of your existing Tesla setup without rewriting your HTTP infrastructure.

Features

  • Works with any Tesla client configuration
  • Preserves Tesla middleware stack
  • Supports all Tesla adapters (Finch, Hackney, Mint, Gun, etc.)
  • Transparent pass-through of Tesla features

Configuration

The Tesla adapter requires a Tesla client to be passed in the options:

# Create your Tesla client
tesla_client = Tesla.client([
  Tesla.Middleware.BaseUrl.new("https://api.example.com"),
  Tesla.Middleware.JSON,
  Tesla.Middleware.Logger
])

# Use with HTTPower
client = HTTPower.new(
  adapter: {HTTPower.Adapter.Tesla, tesla_client}
)

HTTPower.get(client, "/users")

Testing

For testing, you can use Tesla's testing capabilities:

# Use Tesla.Mock for testing
Tesla.Mock.mock(fn
  %{method: :get, url: "https://api.example.com/users"} ->
    %Tesla.Env{status: 200, body: %{"users" => []}}
end)

Or use HTTPower's test mode blocking:

Application.put_env(:httpower, :test_mode, true)
# Requests will be blocked unless using a test adapter

Tesla Client Middleware

The Tesla adapter respects all middleware in your Tesla client:

  • Authentication middleware (Bearer, Basic, OAuth)
  • Retry middleware (note: disable if using HTTPower's retry)
  • Logging middleware
  • JSON encoding/decoding
  • Custom middleware

Example

# Define Tesla client with middleware
defmodule MyApp.ApiClient do
  use Tesla

  plug Tesla.Middleware.BaseUrl, "https://api.example.com"
  plug Tesla.Middleware.JSON
  plug Tesla.Middleware.Headers, [{"authorization", "Bearer token"}]

  # Use Finch adapter
  adapter Tesla.Adapter.Finch, name: MyApp.Finch
end

# Wrap with HTTPower for production features
tesla_client = MyApp.ApiClient.client()

client = HTTPower.new(
  adapter: {HTTPower.Adapter.Tesla, tesla_client},
  circuit_breaker: [threshold: 5],  # Future feature
  rate_limit: [requests: 100, per: :second]  # Future feature
)

# Make requests - Tesla handles HTTP, HTTPower adds reliability
{:ok, response} = HTTPower.get(client, "/users")