uesteibar / Neuron

A GraphQL client for Elixir.

Index

• Installation
• Usage
• Running Locally
• Contributing

Installation

def deps do
  [{:neuron, "~> 5.0.0"}]
end

JSON library

Neuron defaults to using Jason for JSON encoding and decoding. To use Jason, add it to your deps

{:jason, "~> 1.1"}

It is also possible to customize which JSON library that is used

Neuron.Config.set(json_library: AnotherJSONLibrary)

Connection

Neuron defaults to using HTTP(S) protocol with HTTPoison for Connecting to GraphQL endpoint. You can however customize that behaviour, by providing custom library, which should implement Neuron.Connection behaviour:

defmodule MyConnection do
  @behaviour Neuron.Connection

  @impl Neuron.Connection
  def call(body, options) do
    IO.inspect("NEURON CALLED")
    Neuron.Connection.Http.call(body, options)
  end
end

Then set it up in config:

Neuron.Config.set(connection_module: MyConnection)

Usage

iex> Neuron.Config.set(url: "https://example.com/graph")

iex> Neuron.query("""
      {
        films {
          count
        }
      }
    """)

# Response will be:

{:ok, %Neuron.Response{body: %{"data" => %{"films" => %{ "count": 123 }}}, status_code: 200, headers: []}}

# You can also run mutations

iex> Neuron.query("""
      mutation createUser($name: String!) {
        createUser(name: $name) {
          id
          name
        }
      }
    """,
    %{name: "uesteibar"}
    )

# You can also set url and headers as shown below

iex> Neuron.query("""
      mutation createUser($name: String!) {
        createUser(name: $name) {
          id
          name
        }
      }
    """,
    %{name: "uesteibar"},
    url: "https://example.com/graph",
    headers: [authorization: "Bearer <token>"]
    )

Overriding HTTP Timeout

HTTPoison default timeout is 5000ms, in case we need to handle longer timeout, using default Neuron.Connection module, we could set connection_opts which will be passed to HTTPoison. So to override timeout to 15000ms, we could do:

iex> Neuron.Config.set(url: "https://example.com/graph", connection_opts: [recv_timeout: 15_000])

iex> Neuron.query("""
      {
        films {
          count
        }
      }
    """)

We can also set the timeout for a single request by passing the connection_opts to Neuron.query/3 instead:

iex> Neuron.query("...", %{}, connection_opts: [recv_timeout: 15_000])
More extensive documentation can be found at [https://hexdocs.pm/neuron](https://hexdocs.pm/neuron).

## Running locally

Clone the repository

```bash
git clone git@github.com:uesteibar/neuron.git

Install dependencies

cd neuron
mix deps.get

To run the tests

mix test

Style guide

Code is formatted with mix format and mix credo should not show warnings.

To format the code and run static code analysis with credo

mix format
mix credo

Contributing

Pull requests are always welcome =)

The project uses standard-changelog to update the Changelog with each commit message and upgrade the package version. For that reason every contribution should have a title and body that follows the conventional commits standard conventions (e.g. feat(connection): Make it smarter than Jarvis).

To make this process easier, you can do the following:

Install commitizen and cz-conventional-changelog globally

npm i -g commitizen cz-conventional-changelog

Save cz-conventional-changelog as default

echo '{ "path": "cz-conventional-changelog" }' > ~/.czrc

Instead of git commit, you can now run

git cz

and follow the instructions to generate the commit message.