2 files changed, 206 insertions, 0 deletions
diff --git a/test/support/fake_server.ex b/test/support/fake_server.ex
new file mode 100644
index 0000000..bd1fc5a
--- /dev/null
+++ b/test/support/fake_server.ex
@@ -0,0 +1,154 @@
+defmodule Cepis.FakeServer do
+  @moduledoc false
+
+  defstruct [:pid, :agent, :port, :url]
+
+  @type t :: %__MODULE__{pid: pid(), agent: pid(), port: :inet.port_number(), url: String.t()}
+
+  @listen_options [
+    :binary,
+    ip: {127, 0, 0, 1},
+    packet: :http_bin,
+    packet_size: 1_048_576,
+    active: false,
+    reuseaddr: true,
+    backlog: 128
+  ]
+
+  @not_found {404, ~s({"erro":"cep_nao_encontrado","mensagem":"CEP não existe na base do DNE"}),
+              []}
+
+  def start do
+    {:ok, agent} = Agent.start_link(fn -> %{routes: %{}, calls: [], handler: nil} end)
+    parent = self()
+
+    pid =
+      spawn_link(fn ->
+        {:ok, listen} = :gen_tcp.listen(0, @listen_options)
+        {:ok, port} = :inet.port(listen)
+        send(parent, {:listening, self(), port})
+        accept_loop(listen, agent)
+      end)
+
+    port =
+      receive do
+        {:listening, ^pid, port} -> port
+      after
+        5_000 -> raise "fake server did not start"
+      end
+
+    %__MODULE__{pid: pid, agent: agent, port: port, url: "http://127.0.0.1:#{port}"}
+  end
+
+  def stop(%__MODULE__{} = server) do
+    Process.exit(server.pid, :kill)
+    Process.exit(server.agent, :kill)
+    :ok
+  end
+
+  def respond(%__MODULE__{agent: agent}, path, response) do
+    Agent.update(agent, fn state -> put_in(state.routes[path], response) end)
+  end
+
+  def on_request(%__MODULE__{agent: agent}, fun) when is_function(fun, 2) do
+    Agent.update(agent, fn state -> %{state | handler: fun} end)
+  end
+
+  def calls(%__MODULE__{agent: agent}) do
+    Agent.get(agent, & &1.calls)
+  end
+
+  def count(%__MODULE__{} = server, prefix) do
+    server |> calls() |> Enum.count(&String.starts_with?(&1, prefix))
+  end
+
+  defp accept_loop(listen, agent) do
+    case :gen_tcp.accept(listen) do
+      {:ok, socket} ->
+        worker = spawn(fn -> serve(socket, agent) end)
+        :gen_tcp.controlling_process(socket, worker)
+        send(worker, :ready)
+        accept_loop(listen, agent)
+
+      {:error, _reason} ->
+        :ok
+    end
+  end
+
+  defp serve(socket, agent) do
+    receive do
+      :ready -> :ok
+    after
+      5_000 -> :ok
+    end
+
+    with {:ok, path} <- read_request(socket) do
+      {status, body, headers} = dispatch(agent, path)
+      :gen_tcp.send(socket, encode(status, body, headers))
+    end
+
+    :gen_tcp.close(socket)
+  end
+
+  defp read_request(socket) do
+    case :gen_tcp.recv(socket, 0, 5_000) do
+      {:ok, {:http_request, _method, {:abs_path, path}, _version}} ->
+        with :ok <- drain_headers(socket), do: {:ok, path}
+
+      other ->
+        other
+    end
+  end
+
+  defp drain_headers(socket) do
+    case :gen_tcp.recv(socket, 0, 5_000) do
+      {:ok, :http_eoh} -> :ok
+      {:ok, {:http_header, _length, _field, _reserved, _value}} -> drain_headers(socket)
+      other -> other
+    end
+  end
+
+  defp dispatch(agent, path) do
+    Agent.get_and_update(agent, fn state ->
+      state = %{state | calls: state.calls ++ [path]}
+      select(state, path)
+    end)
+  end
+
+  defp select(%{handler: handler} = state, path) when is_function(handler, 2) do
+    {handler.(path, length(state.calls)), state}
+  end
+
+  defp select(state, path) do
+    case Map.get(state.routes, path) do
+      nil -> {@not_found, state}
+      [single] -> {single, state}
+      [next | rest] -> {next, put_in(state.routes[path], rest)}
+      response -> {response, state}
+    end
+  end
+
+  defp encode(status, body, headers) do
+    payload = IO.iodata_to_binary(body)
+
+    head = [
+      "HTTP/1.1 #{status} #{reason(status)}\r\n",
+      Enum.map(headers, fn {key, value} -> "#{key}: #{value}\r\n" end),
+      "content-type: text/plain; charset=utf-8\r\n",
+      "content-length: #{byte_size(payload)}\r\n",
+      "connection: close\r\n\r\n"
+    ]
+
+    IO.iodata_to_binary([head, payload])
+  end
+
+  defp reason(200), do: "OK"
+  defp reason(400), do: "Bad Request"
+  defp reason(404), do: "Not Found"
+  defp reason(429), do: "Too Many Requests"
+  defp reason(500), do: "Internal Server Error"
+  defp reason(502), do: "Bad Gateway"
+  defp reason(503), do: "Service Unavailable"
+  defp reason(504), do: "Gateway Timeout"
+  defp reason(_status), do: "Status"
+end
diff --git a/test/support/server_case.ex b/test/support/server_case.ex
new file mode 100644
index 0000000..a64bb05
--- /dev/null
+++ b/test/support/server_case.ex
@@ -0,0 +1,52 @@
+defmodule Cepis.ServerCase do
+  @moduledoc false
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      import Cepis.ServerCase
+
+      alias Cepis.FakeServer
+    end
+  end
+
+  setup do
+    server = Cepis.FakeServer.start()
+    on_exit(fn -> Cepis.FakeServer.stop(server) end)
+
+    client =
+      Cepis.Client.new(
+        base_url: server.url,
+        timeout: 5_000,
+        backoff_base: 1,
+        backoff_max: 10
+      )
+
+    %{server: server, client: client}
+  end
+
+  @address %{
+    "cep" => "01001000",
+    "logradouro" => "Praça da Sé",
+    "complemento" => "lado ímpar",
+    "unidade" => "",
+    "bairro" => "Sé",
+    "localidade" => "São Paulo",
+    "uf" => "SP",
+    "estado" => "São Paulo",
+    "regiao" => "Sudeste",
+    "ibge" => "3550308",
+    "gia" => "1004",
+    "ddd" => "11",
+    "siafi" => "7107"
+  }
+
+  @csv_header "cep,logradouro,complemento,unidade,bairro,localidade,uf,estado,regiao,ibge,gia,ddd,siafi"
+
+  def address_fixture(extra \\ %{}), do: Map.merge(@address, extra)
+
+  def json(term), do: IO.iodata_to_binary(:json.encode(term))
+
+  def csv(rows), do: Enum.join([@csv_header | rows], "\n") <> "\n"
+end