Merge pull request #34 from angelikatyborska/allow-custom-http-client

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [Unreleased]
+
+- Replace HTTPoison with hackney
+- Make hackney optional, allow passing a custom HTTPClient
+
 ## 1.0.0 (2020-04-13)
 
 ### Changed

README.md

@@ -37,12 +37,13 @@ HTTP/1.1 200 OK
 
 Make sure to read about the [prerequisites](#prerequisites) first.
 
-Add Vnu as a dependency to your project's `mix.exs`:
+Add Vnu as a dependency to your project's `mix.exs`. To use the built-in, Hackney-based HTTP client adapter, add `:hackney` too:
 
 ```elixir
 defp deps do
   [
-    {:vnu, "~> 1.0", only: [:dev, :test], runtime: false}
+    {:vnu, "~> 1.0", only: [:dev, :test], runtime: false},
+    {:hackney, "~> 1.17"}
   ]
 end
 ```

lib/mix/tasks/vnu.validate.html.ex

@@ -19,6 +19,8 @@ defmodule Mix.Tasks.Vnu.Validate.Html do
     Their presence will mean the document is invalid. Defaults to `false`.
   - `--filter` - A module implementing the `Vnu.MessageFilter` behavior that will be used to exclude messages matching the filter from the result.
     Defaults to `nil` (no excluded messages).
+  - `--http-client` - A module implementing the `Vnu.HTTPClient` behaviour that will be used to make the HTTP request to the server.
+  Defaults to `Vnu.HTTPClient.Hackney`.
 
   ## Exit code
 

lib/vnu.ex

@@ -15,6 +15,8 @@ defmodule Vnu do
   Defaults to `http://localhost:8888`.
   - `:filter` - A module implementing the `Vnu.MessageFilter` behavior that will be used to exclude messages matching the filter from the result.
   Defaults to `nil` (no excluded messages).
+  - `:http_client` - A module implementing the `Vnu.HTTPClient` behaviour that will be used to make the HTTP request to the server.
+  Defaults to `Vnu.HTTPClient.Hackney`.
 
 
   ## Examples
@@ -58,7 +60,7 @@ defmodule Vnu do
       iex> Vnu.validate_html("", server_url: "http://wrong-domain")
       {:error, %Vnu.Error{
         reason: :unexpected_server_response,
-        message: "Could not contact the server, got error: %HTTPoison.Error{id: nil, reason: :nxdomain}"
+        message: "Could not contact the server, got error: :nxdomain"
       }}
   """
 
@@ -101,7 +103,7 @@ defmodule Vnu do
       iex> Vnu.validate_css("", server_url: "http://wrong-domain")
       {:error, %Vnu.Error{
         reason: :unexpected_server_response,
-        message: "Could not contact the server, got error: %HTTPoison.Error{id: nil, reason: :nxdomain}"
+        message: "Could not contact the server, got error: :nxdomain"
       }}
   """
 
@@ -124,9 +126,6 @@ defmodule Vnu do
 
   See `validate_html/2` for the list of options and other details.
 
-  ## Options
-  - `:server_url` - The URL of [the Checker server](https://github.com/validator/validator). Defaults to `http://localhost:8888`.
-
   ## Examples
 
       iex> Vnu.validate_svg(~S(
@@ -156,7 +155,7 @@ defmodule Vnu do
       iex> Vnu.validate_svg("", server_url: "http://wrong-domain")
       {:error, %Vnu.Error{
         reason: :unexpected_server_response,
-        message: "Could not contact the server, got error: %HTTPoison.Error{id: nil, reason: :nxdomain}"
+        message: "Could not contact the server, got error: :nxdomain"
       }}
   """
 
@@ -181,6 +180,8 @@ defmodule Vnu do
   - `:server_url` - The URL of [the Checker server](https://github.com/validator/validator). Defaults to `http://localhost:8888`.
   - `:fail_on_warnings` - Messages of type `:info` and subtype `:warning` will be treated as if they were validation errors.
     Their presence will mean the document is invalid. Defaults to `false`.
+  - `:http_client` - A module implementing the `Vnu.HTTPClient` behaviour that will be used to make the HTTP request to the server.
+  Defaults to `Vnu.HTTPClient.Hackney`.
 
   ## Examples
 

lib/vnu/assertions.ex

@@ -13,6 +13,8 @@ defmodule Vnu.Assertions do
     Their presence will mean the document is invalid. Defaults to `false`.
   - `:filter` - A module implementing the `Vnu.MessageFilter` behavior that will be used to exclude messages matching the filter from the result.
     Defaults to `nil` (no excluded messages).
+  - `:http_client` - A module implementing the `Vnu.HTTPClient` behaviour that will be used to make the HTTP request to the server.
+    Defaults to `Vnu.HTTPClient.Hackney`.
   - `:message_print_limit` - The maximum number of validation messages that will me printed in the error when the assertion fails.
     Can be an integer or `:infinity`. Defaults to `:infinity`.
   """

lib/vnu/cli.ex

@@ -8,7 +8,12 @@ defmodule Vnu.CLI do
   def validate(argv, format) do
     {opts, files, invalid_args} =
       OptionParser.parse(argv,
-        strict: [server_url: :string, fail_on_warnings: :boolean, filter: :string]
+        strict: [
+          http_client: :string,
+          server_url: :string,
+          fail_on_warnings: :boolean,
+          filter: :string
+        ]
       )
 
     if invalid_args != [] do
@@ -21,9 +26,21 @@ defmodule Vnu.CLI do
       Mix.raise("No files given")
     end
 
-    opts = Keyword.update(opts, :filter, nil, &Module.concat([&1]))
+    opts =
+      if Keyword.get(opts, :http_client) do
+        Keyword.update!(opts, :http_client, &Module.concat([&1]))
+      else
+        opts
+      end
+
+    opts =
+      if Keyword.get(opts, :filter) do
+        Keyword.update!(opts, :filter, &Module.concat([&1]))
+      else
+        opts
+      end
 
-    if Keyword.get(opts, :filter, nil) do
+    if Keyword.get(opts, :filter) || Keyword.get(opts, :http_client) do
       # must compile to ensure the filter module is available
       Mix.Task.run("compile", [])
     end

lib/vnu/config.ex

@@ -3,15 +3,21 @@ defmodule Vnu.Config do
 
   alias Vnu.Error
 
-  defstruct [:server_url, :format, :filter]
+  defstruct [:http_client, :server_url, :format, :filter]
 
-  @defaults [server_url: "http://localhost:8888", format: :html, filter: nil]
+  @defaults [
+    http_client: Vnu.HTTPClient.Hackney,
+    server_url: "http://localhost:8888",
+    format: :html,
+    filter: nil
+  ]
 
   @doc false
   def new(opts) when is_list(opts) do
     opts = Keyword.merge(@defaults, opts)
 
     %__MODULE__{}
+    |> set_http_client(opts)
     |> set_server_url(opts)
     |> set_format(opts)
     |> set_filter(opts)
@@ -25,7 +31,34 @@ defmodule Vnu.Config do
     end
   end
 
-  defp set_server_url(config, opts) do
+  defp set_http_client(config, opts) do
+    http_client = Keyword.get(opts, :http_client)
+
+    cond do
+      !is_atom(http_client) ->
+        {:error,
+         Error.new(
+           :invalid_config,
+           "Expected http_client to be a module, got: #{inspect(http_client)}"
+         )}
+
+      !Code.ensure_loaded?(http_client) || !Kernel.function_exported?(http_client, :post, 3) ->
+        {:error,
+         Error.new(
+           :invalid_config,
+           "Expected http_client to be a module that implements the Vnu.HTTPClient behaviour, got: #{
+             inspect(http_client)
+           }"
+         )}
+
+      true ->
+        {:ok, %{config | http_client: http_client}}
+    end
+  end
+
+  defp set_server_url({:error, error}, _opts), do: {:error, error}
+
+  defp set_server_url({:ok, config}, opts) do
     server_url = Keyword.get(opts, :server_url)
 
     if is_bitstring(server_url) do

lib/vnu/http.ex

@@ -22,15 +22,15 @@ defmodule Vnu.HTTP do
 
     headers = [{"Content-Type", "#{content_type}; charset=utf-8"}]
 
-    case HTTPoison.post(url, html, headers, follow_redirect: true) do
-      {:ok, %HTTPoison.Response{body: body, status_code: 200}} ->
+    case config.http_client.post(url, html, headers) do
+      {:ok, %{body: body, status: 200}} ->
         parse_body(body)
 
-      {:ok, %HTTPoison.Response{body: body, status_code: status_code}} ->
+      {:ok, %{body: body, status: status}} ->
         {:error,
          Error.new(
            :unexpected_server_response,
-           "Expected the server to respond with status code 200, instead got #{status_code} with body: #{
+           "Expected the server to respond with status code 200, instead got #{status} with body: #{
              inspect(body)
            }"
          )}

lib/vnu/http_client.ex

@@ -0,0 +1,18 @@
+defmodule Vnu.HTTPClient do
+  @moduledoc """
+  Specification for a Vnu HTTP client.
+  """
+
+  @type url() :: String.t()
+  @type body() :: String.t()
+  @type header() :: {String.t(), String.t()}
+
+  @type status() :: non_neg_integer()
+
+  @type response() :: %{status: status(), body: body()}
+
+  @doc """
+  A callback to make a POST HTTP request.
+  """
+  @callback post(url(), body(), [header()]) :: {:ok, response()} | {:error, any()}
+end

lib/vnu/http_client/hackney.ex

@@ -0,0 +1,34 @@
+defmodule Vnu.HTTPClient.Hackney do
+  @moduledoc """
+  HTTPoison-based HTTP client adapter.
+  """
+
+  @behaviour Vnu.HTTPClient
+  require Logger
+
+  @impl true
+  def post(url, body, headers) do
+    if Code.ensure_loaded?(:hackney) do
+      with {:ok, status, _headers, body_ref} <-
+             :hackney.request(:post, url, headers, body, follow_redirect: true),
+           {:ok, body} <- :hackney.body(body_ref) do
+        {:ok, %{status: status, body: body}}
+      else
+        {:error, error} ->
+          {:error, error}
+      end
+    else
+      Logger.error("""
+      Could not find hackney dependency.
+
+      Please add :httpoison to your dependencies:
+
+          {:hackney, "~> 1.17"}
+
+      Or use a different HTTP client. See Vnu.HTTPClient for more information.
+      """)
+
+      raise "missing hackney dependency"
+    end
+  end
+end

mix-older-deps.lock

@@ -10,7 +10,6 @@
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "ex_doc": {:hex, :ex_doc, "0.21.3", "857ec876b35a587c5d9148a2512e952e24c24345552259464b98bfbb883c7b42", [:mix], [{:earmark, "~> 1.4", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "0db1ee8d1547ab4877c5b5dffc6604ef9454e189928d5ba8967d4a58a801f161"},
   "hackney": {:hex, :hackney, "1.15.2", "07e33c794f8f8964ee86cebec1a8ed88db5070e52e904b8f12209773c1036085", [:rebar3], [{:certifi, "2.5.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.5", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm", "e0100f8ef7d1124222c11ad362c857d3df7cb5f4204054f9f0f4a728666591fc"},
-  "httpoison": {:hex, :httpoison, "1.0.0", "1f02f827148d945d40b24f0b0a89afe40bfe037171a6cf70f2486976d86921cd", [:mix], [{:hackney, "~> 1.8", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm", "07967c56199f716ce9adb27415ccea1bd76c44f777dd0a6d4166c3d932f37fdf"},
   "idna": {:hex, :idna, "6.0.0", "689c46cbcdf3524c44d5f3dde8001f364cd7608a99556d8fbd8239a5798d4c10", [:rebar3], [{:unicode_util_compat, "0.4.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "4bdd305eb64e18b0273864920695cb18d7a2021f31a11b9c5fbcd9a253f936e2"},
   "jason": {:hex, :jason, "1.0.0", "0f7cfa9bdb23fed721ec05419bcee2b2c21a77e926bce0deda029b5adc716fe2", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "b96c400e04b7b765c0854c05a4966323e90c0d11fee0483b1567cda079abb205"},
   "makeup": {:hex, :makeup, "1.0.1", "82f332e461dc6c79dbd82fbe2a9c10d48ed07146f0a478286e590c83c52010b5", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "49736fe5b66a08d8575bf5321d716bac5da20c8e6b97714fec2bcd6febcfa1f8"},

mix.exs

@@ -12,7 +12,7 @@ defmodule Vnu.MixProject do
       deps: deps(),
       aliases: aliases(),
       docs: [extras: ["README.md", "CHANGELOG.md"]],
-      dialyzer: [plt_add_apps: [:mix, :ex_unit]],
+      dialyzer: [plt_add_apps: [:mix, :ex_unit, :hackney]],
       description: description(),
       package: package(),
       name: "Vnu",
@@ -49,8 +49,8 @@ defmodule Vnu.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      {:httpoison, "~> 1.0"},
       {:jason, "~> 1.0"},
+      {:hackney, "~> 1.17", optional: true},
       {:dialyxir, "~> 1.0", only: [:dev], runtime: false},
       {:credo, "~> 1.0", only: [:dev], runtime: false},
       {:ex_doc, "~> 0.21", only: [:dev], runtime: false},

mix.lock

@@ -7,14 +7,12 @@
   "cowlib": {:hex, :cowlib, "2.9.1", "61a6c7c50cf07fdd24b2f45b89500bb93b6686579b069a89f88cb211e1125c78", [:rebar3], [], "hexpm", "e4175dc240a70d996156160891e1c62238ede1729e45740bdd38064dad476170"},
   "credo": {:hex, :credo, "1.5.5", "e8f422026f553bc3bebb81c8e8bf1932f498ca03339856c7fec63d3faac8424b", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "dd8623ab7091956a855dc9f3062486add9c52d310dfd62748779c4315d8247de"},
   "dialyxir": {:hex, :dialyxir, "1.1.0", "c5aab0d6e71e5522e77beff7ba9e08f8e02bad90dfbeffae60eaf0cb47e29488", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "07ea8e49c45f15264ebe6d5b93799d4dd56a44036cf42d0ad9c960bc266c0b9a"},
-  "earmark": {:hex, :earmark, "1.4.3", "364ca2e9710f6bff494117dbbd53880d84bebb692dafc3a78eb50aa3183f2bfd", [:mix], [], "hexpm", "8cf8a291ebf1c7b9539e3cddb19e9cef066c2441b1640f13c34c1d3cfc825fec"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.12", "b245e875ec0a311a342320da0551da407d9d2b65d98f7a9597ae078615af3449", [:mix], [], "hexpm", "711e2cc4d64abb7d566d43f54b78f7dc129308a63bc103fbd88550d2174b3160"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "ex_doc": {:hex, :ex_doc, "0.24.0", "2df14354835afaabdf87cb2971ea9485d8a36ff590e4b6c250b4f60c8fdf9143", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "a0f4bcff21ceebea48414e49885d2a3e542200f76a2facf3f8faa54935eeb721"},
   "excoveralls": {:hex, :excoveralls, "0.14.0", "4b562d2acd87def01a3d1621e40037fdbf99f495ed3a8570dfcf1ab24e15f76d", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "94f17478b0cca020bcd85ce7eafea82d2856f7ed022be777734a2f864d36091a"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
   "hackney": {:hex, :hackney, "1.17.0", "717ea195fd2f898d9fe9f1ce0afcc2621a41ecfe137fae57e7fe6e9484b9aa99", [:rebar3], [{:certifi, "~>2.5", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~>6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~>1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~>1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "64c22225f1ea8855f584720c0e5b3cd14095703af1c9fbc845ba042811dc671c"},
-  "httpoison": {:hex, :httpoison, "1.8.0", "6b85dea15820b7804ef607ff78406ab449dd78bed923a49c7160e1886e987a3d", [:mix], [{:hackney, "~> 1.17", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm", "28089eaa98cf90c66265b6b5ad87c59a3729bea2e74e9d08f9b51eb9729b3c3a"},
   "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
   "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
   "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},

test/vnu/config_test.exs

@@ -5,7 +5,37 @@ defmodule Vnu.ConfigTest do
   describe "new" do
     test "defaults" do
       {:ok, config} = Config.new([])
-      assert config == %Config{server_url: "http://localhost:8888/", format: :html}
+
+      assert config == %Config{
+               http_client: Vnu.HTTPClient.Hackney,
+               server_url: "http://localhost:8888/",
+               format: :html
+             }
+    end
+
+    test "http_client must be a module" do
+      {:error, %Error{} = error} = Config.new(http_client: "apple")
+
+      assert error.reason == :invalid_config
+      assert error.message == "Expected http_client to be a module, got: \"apple\""
+    end
+
+    test "http_client must implement exist" do
+      {:error, %Error{} = error} = Config.new(http_client: SomeModule.That.DoesntExist)
+
+      assert error.reason == :invalid_config
+
+      assert error.message ==
+               "Expected http_client to be a module that implements the Vnu.HTTPClient behaviour, got: SomeModule.That.DoesntExist"
+    end
+
+    test "http_client must implement the Vnu.HTTPClient behaviour" do
+      {:error, %Error{} = error} = Config.new(http_client: String)
+
+      assert error.reason == :invalid_config
+
+      assert error.message ==
+               "Expected http_client to be a module that implements the Vnu.HTTPClient behaviour, got: String"
     end
 
     test "adds trailing slash to server_url" do

test/vnu/http_test.exs

@@ -121,5 +121,32 @@ defmodule Vnu.HTTPTest do
           Config.new!(server_url: "https://validator.w3.org/nu", format: :html)
         )
     end
+
+    test "works with a custom HTTPClient" do
+      defmodule MyHTTPClient do
+        def post(_url, body, _header) do
+          if is_bitstring(body) do
+            {:ok,
+             %{
+               status: 200,
+               body: Jason.encode!(%{messages: [%{type: "error", message: body}]})
+             }}
+          else
+            {:error, "oops"}
+          end
+        end
+      end
+
+      config = Config.new!(http_client: MyHTTPClient, format: :html)
+
+      {:ok, %Result{} = result} = HTTP.get_result("echo... echo... echo...", config)
+
+      assert result.messages == [%Vnu.Message{message: "echo... echo... echo...", type: :error}]
+
+      {:error, %Error{} = error} = HTTP.get_result(123, config)
+
+      assert error.message == "Could not contact the server, got error: \"oops\""
+      assert error.reason == :unexpected_server_response
+    end
   end
 end