chore: move modules to its own file (#615)

lib/tesla/middleware/base_url.ex

@@ -0,0 +1,52 @@
+defmodule Tesla.Middleware.BaseUrl do
+  @moduledoc """
+  Set base URL for all requests.
+
+  The base URL will be prepended to request path/URL only
+  if it does not include http(s).
+
+  ## Examples
+
+  ```
+  defmodule MyClient do
+    use Tesla
+
+    plug Tesla.Middleware.BaseUrl, "https://example.com/foo"
+  end
+
+  MyClient.get("/path") # equals to GET https://example.com/foo/path
+  MyClient.get("path") # equals to GET https://example.com/foo/path
+  MyClient.get("") # equals to GET https://example.com/foo
+  MyClient.get("http://example.com/bar") # equals to GET http://example.com/bar
+  ```
+  """
+
+  @behaviour Tesla.Middleware
+
+  @impl Tesla.Middleware
+  def call(env, next, base) do
+    env
+    |> apply_base(base)
+    |> Tesla.run(next)
+  end
+
+  defp apply_base(env, base) do
+    if Regex.match?(~r/^https?:\/\//i, env.url) do
+      # skip if url is already with scheme
+      env
+    else
+      %{env | url: join(base, env.url)}
+    end
+  end
+
+  defp join(base, url) do
+    case {String.last(to_string(base)), url} do
+      {nil, url} -> url
+      {"/", "/" <> rest} -> base <> rest
+      {"/", rest} -> base <> rest
+      {_, ""} -> base
+      {_, "/" <> rest} -> base <> "/" <> rest
+      {_, rest} -> base <> "/" <> rest
+    end
+  end
+end

lib/tesla/middleware/headers.ex

@@ -0,0 +1,24 @@
+defmodule Tesla.Middleware.Headers do
+  @moduledoc """
+  Set default headers for all requests
+
+  ## Examples
+
+  ```
+  defmodule Myclient do
+    use Tesla
+
+    plug Tesla.Middleware.Headers, [{"user-agent", "Tesla"}]
+  end
+  ```
+  """
+
+  @behaviour Tesla.Middleware
+
+  @impl Tesla.Middleware
+  def call(env, next, headers) do
+    env
+    |> Tesla.put_headers(headers)
+    |> Tesla.run(next)
+  end
+end

lib/tesla/middleware/opts.ex

@@ -0,0 +1,22 @@
+defmodule Tesla.Middleware.Opts do
+  @moduledoc """
+  Set default opts for all requests.
+
+  ## Examples
+
+  ```
+  defmodule Myclient do
+    use Tesla
+
+    plug Tesla.Middleware.Opts, [some: "option"]
+  end
+  ```
+  """
+
+  @behaviour Tesla.Middleware
+
+  @impl Tesla.Middleware
+  def call(env, next, opts) do
+    Tesla.run(%{env | opts: env.opts ++ opts}, next)
+  end
+end

lib/tesla/middleware/query.ex

@@ -0,0 +1,30 @@
+defmodule Tesla.Middleware.Query do
+  @moduledoc """
+  Set default query params for all requests
+
+  ## Examples
+
+  ```
+  defmodule Myclient do
+    use Tesla
+
+    plug Tesla.Middleware.Query, [token: "some-token"]
+  end
+  ```
+  """
+
+  @behaviour Tesla.Middleware
+
+  @impl Tesla.Middleware
+  def call(env, next, query) do
+    env
+    |> merge(query)
+    |> Tesla.run(next)
+  end
+
+  defp merge(env, nil), do: env
+
+  defp merge(env, query) do
+    Map.update!(env, :query, &(&1 ++ query))
+  end
+end