Add support for HEAD request in hackney

fixture/vcr_cassettes/hackney_head.json

@@ -0,0 +1,31 @@
+[
+  {
+    "request": {
+      "body": "",
+      "headers": [],
+      "method": "head",
+      "options": [],
+      "request_body": "",
+      "url": "http://www.example.com"
+    },
+    "response": {
+      "body": null,
+      "headers": {
+        "Content-Encoding": "gzip",
+        "Accept-Ranges": "bytes",
+        "Cache-Control": "max-age=604800",
+        "Content-Type": "text/html",
+        "Date": "Fri, 27 Jan 2017 12:44:46 GMT",
+        "Etag": "\"359670651+gzip\"",
+        "Expires": "Fri, 03 Feb 2017 12:44:46 GMT",
+        "Last-Modified": "Fri, 09 Aug 2013 23:54:35 GMT",
+        "Server": "ECS (ewr/15BD)",
+        "X-Cache": "HIT",
+        "x-ec-custom-error": "1",
+        "Content-Length": "606"
+      },
+      "status_code": 200,
+      "type": "ok"
+    }
+  }
+]

fixture/vcr_cassettes/httpoison_head.json

@@ -0,0 +1,31 @@
+[
+  {
+    "request": {
+      "body": "",
+      "headers": [],
+      "method": "head",
+      "options": [],
+      "request_body": "",
+      "url": "http://example.com"
+    },
+    "response": {
+      "body": null,
+      "headers": {
+        "Content-Encoding": "gzip",
+        "Accept-Ranges": "bytes",
+        "Cache-Control": "max-age=604800",
+        "Content-Type": "text/html",
+        "Date": "Fri, 27 Jan 2017 12:44:45 GMT",
+        "Etag": "\"359670651+gzip\"",
+        "Expires": "Fri, 03 Feb 2017 12:44:45 GMT",
+        "Last-Modified": "Fri, 09 Aug 2013 23:54:35 GMT",
+        "Server": "ECS (ewr/15BD)",
+        "X-Cache": "HIT",
+        "x-ec-custom-error": "1",
+        "Content-Length": "606"
+      },
+      "status_code": 200,
+      "type": "ok"
+    }
+  }
+]

lib/exvcr/adapter/hackney.ex

@@ -56,6 +56,11 @@ defmodule ExVCR.Adapter.Hackney do
     {:ok, status_code, filtered_headers, reference}
   end
 
+  defp apply_filters({:ok, status_code, headers}) do
+    filtered_headers = ExVCR.Filter.remove_blacklisted_headers(headers)
+    {:ok, status_code, filtered_headers}
+  end
+
   defp apply_filters({:error, reason}) do
     {:error, reason}
   end
@@ -65,6 +70,7 @@ defmodule ExVCR.Adapter.Hackney do
   """
   def hook_response_from_cache(_request, nil), do: nil
   def hook_response_from_cache(_request, %ExVCR.Response{type: "error"} = response), do: response
+  def hook_response_from_cache(_request, %ExVCR.Response{body: nil} = response), do: response
   def hook_response_from_cache([_, _, _, _, opts], %ExVCR.Response{body: body} = response) do
     if :with_body in opts || {:with_body, true} in opts do
       response
@@ -102,6 +108,20 @@ defmodule ExVCR.Adapter.Hackney do
     end
   end
 
+  @doc """
+  Returns the response from the ExVCR.Reponse record.
+  """
+  def get_response_value_from_cache(response) do
+    if response.type == "error" do
+      {:error, response.body}
+    else
+      case response.body do
+        nil -> {:ok, response.status_code, response.headers}
+        _   -> {:ok, response.status_code, response.headers, response.body}
+      end
+    end
+  end
+
   @doc """
   Default definitions for stub.
   """

lib/exvcr/adapter/hackney/converter.ex

@@ -59,6 +59,14 @@ defmodule ExVCR.Adapter.Hackney.Converter do
     }
   end
 
+  defp response_to_string({:ok, status_code, headers}) do
+    %ExVCR.Response{
+      type: "ok",
+      status_code: status_code,
+      headers: parse_headers(headers)
+    }
+  end
+
   defp response_to_string({:error, reason}) do
     %ExVCR.Response{
       type: "error",

lib/exvcr/json.ex

@@ -14,9 +14,11 @@ defmodule ExVCR.JSON do
     File.write!(file_name, JSX.prettify!(json))
   end
 
-  defp gunzip_recording(recording) do
-    %{request: request, response: response} = recording
+  defp gunzip_recording(recording = %{request: _, response: %ExVCR.Response{body: nil}}) do
+    recording
+  end
 
+  defp gunzip_recording(recording = %{request: request, response: response}) do
     encoding_header = List.keyfind(response.headers, "Content-Encoding", 0)
 
     case encoding_header do
@@ -55,9 +57,14 @@ defmodule ExVCR.JSON do
     %{recording | "response" => gzip_response(recording["response"])}
   end
 
+  defp gzip_response(response = %{"body" => nil, "headers" => %{"Content-Encoding" => "gzip"}}) do
+    response
+  end
+
   defp gzip_response(response = %{"headers" => %{"Content-Encoding" => "gzip"}}) do
-        encoded_body = :zlib.gzip(response["body"])
-        %{ response | "body" => encoded_body }
+    encoded_body = :zlib.gzip(response["body"])
+    %{ response | "body" => encoded_body }
   end
+
   defp gzip_response(response), do: response
 end

test/adapter_hackney_test.exs

@@ -17,6 +17,14 @@ defmodule ExVCR.Adapter.HackneyTest do
     end
   end
 
+  test "hackney head request" do
+    use_cassette "hackney_head" do
+      {:ok, status_code, headers} = :hackney.request(:head, "http://www.example.com", [], [], [])
+      assert status_code == 200
+      assert List.keyfind(headers, "Content-Type", 0) == {"Content-Type", "text/html"}
+    end
+  end
+
   test "hackney request with gzipped response" do
     use_cassette "hackney_get_gzipped" do
       headers = [{"Accept-Encoding", "gzip, deflate"}]
@@ -80,6 +88,15 @@ defmodule ExVCR.Adapter.HackneyTest do
     end
   end
 
+  test "head request" do
+    use_cassette "httpoison_head" do
+      response = HTTPoison.head!("http://example.com")
+      assert response.body == ""
+      assert response.status_code == 200
+      assert List.keyfind(response.headers, "Content-Type", 0) == {"Content-Type", "text/html"}
+    end
+  end
+
   test "post method" do
     use_cassette "httpoison_post" do
       assert_response HTTPoison.post!("http://httpbin.org/post", "test")