From 5ffde91951a88abf4041b18269032fbc3d4a4576 Mon Sep 17 00:00:00 2001
From: Alessandro Mencarini <alessandro@driftrock.com>
Date: Fri, 12 Jan 2018 10:03:52 +0000
Subject: [PATCH] Add check for HTTP_PROXY env var

If no proxy option is passed, this will check if a env var for proxies is set.
If none is set everything will operate as usual.

Fixes #305
---
 .gitignore                   |  1 +
 lib/httpoison/base.ex        | 30 ++++++++++++++---
 test/httpoison_base_test.exs | 64 ++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index c0be748..1b82591 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,4 @@ erl_crash.dump
 mix.lock
 /.idea
 *.iml
+/.elixir_ls
diff --git a/lib/httpoison/base.ex b/lib/httpoison/base.ex
index b8052ed..605636e 100644
--- a/lib/httpoison/base.ex
+++ b/lib/httpoison/base.ex
@@ -401,8 +401,6 @@ defmodule HTTPoison.Base do
     recv_timeout = Keyword.get options, :recv_timeout
     stream_to = Keyword.get options, :stream_to
     async = Keyword.get options, :async
-    proxy = Keyword.get options, :proxy
-    proxy_auth = Keyword.get options, :proxy_auth
     ssl = Keyword.get options, :ssl
     follow_redirect = Keyword.get options, :follow_redirect
     max_redirect = Keyword.get options, :max_redirect
@@ -411,8 +409,6 @@ defmodule HTTPoison.Base do
 
     hn_options = if timeout, do: [{:connect_timeout, timeout} | hn_options], else: hn_options
     hn_options = if recv_timeout, do: [{:recv_timeout, recv_timeout} | hn_options], else: hn_options
-    hn_options = if proxy, do: [{:proxy, proxy} | hn_options], else: hn_options
-    hn_options = if proxy_auth, do: [{:proxy_auth, proxy_auth} | hn_options], else: hn_options
     hn_options = if ssl, do: [{:ssl_options, ssl} | hn_options], else: hn_options
     hn_options = if follow_redirect, do: [{:follow_redirect, follow_redirect} | hn_options], else: hn_options
     hn_options = if max_redirect, do: [{:max_redirect, max_redirect} | hn_options], else: hn_options
@@ -431,10 +427,34 @@ defmodule HTTPoison.Base do
     hn_options
   end
 
+  defp build_hackney_proxy_options(options, request_url) do
+    proxy =
+      if Keyword.has_key?(options, :proxy) do
+        Keyword.get(options, :proxy)
+      else
+        case URI.parse(request_url).scheme do
+          "http" -> System.get_env("HTTP_PROXY") || System.get_env("http_proxy")
+          "https" -> System.get_env("HTTPS_PROXY") || System.get_env("https_proxy")
+          _ -> nil
+        end
+      end
+
+    proxy_auth = Keyword.get(options, :proxy_auth)
+
+    hn_proxy_options = if proxy, do: [{:proxy, proxy}], else: []
+
+    hn_proxy_options =
+      if proxy_auth, do: [{:proxy_auth, proxy_auth} | hn_proxy_options], else: hn_proxy_options
+
+    hn_proxy_options
+  end
+
+
   @doc false
   @spec request(atom, atom, binary, body, headers, any, fun, fun, fun) :: {:ok, Response.t | AsyncResponse.t} | {:error, Error.t}
   def request(module, method, request_url, request_body, request_headers, options, process_status_code, process_headers, process_response_body) do
-    hn_options = build_hackney_options(module, options)
+    hn_proxy_options = build_hackney_proxy_options(options, request_url)
+    hn_options = hn_proxy_options ++ build_hackney_options(module, options)
 
     case do_request(method, request_url, request_headers, request_body, hn_options) do
       {:ok, status_code, headers} -> response(process_status_code, process_headers, process_response_body, status_code, headers, "", request_url)
diff --git a/test/httpoison_base_test.exs b/test/httpoison_base_test.exs
index ff63460..897c617 100644
--- a/test/httpoison_base_test.exs
+++ b/test/httpoison_base_test.exs
@@ -146,6 +146,70 @@ defmodule HTTPoisonBaseTest do
     assert validate :hackney
   end
 
+  test "having http_proxy env variable set on http requests" do
+    expect(System, :get_env, [{["HTTP_PROXY"], "proxy"}])
+
+    expect(:hackney, :request, [
+      {[:post, "http://localhost", [], "body", [proxy: "proxy"]], {:ok, 200, "headers", :client}}
+    ])
+
+    expect(:hackney, :body, 1, {:ok, "response"})
+
+    assert HTTPoison.post!("localhost", "body") ==
+             %HTTPoison.Response{
+               status_code: 200,
+               headers: "headers",
+               body: "response",
+               request_url: "http://localhost"
+             }
+
+    assert validate(:hackney)
+  end
+
+  test "having https_proxy env variable set on https requests" do
+    expect(System, :get_env, [{["HTTPS_PROXY"], "proxy"}])
+
+    expect(:hackney, :request, [
+      {[:post, "https://localhost", [], "body", [proxy: "proxy"]], {:ok, 200, "headers", :client}}
+    ])
+
+    expect(:hackney, :body, 1, {:ok, "response"})
+
+    assert HTTPoison.post!("https://localhost", "body") ==
+             %HTTPoison.Response{
+               status_code: 200,
+               headers: "headers",
+               body: "response",
+               request_url: "https://localhost"
+             }
+
+    assert validate(:hackney)
+  end
+
+  test "having https_proxy env variable set on http requests" do
+    expect(System, :get_env, [
+      {["HTTPS_PROXY"], "proxy"},
+      {["HTTP_PROXY"], nil},
+      {["http_proxy"], nil}
+    ])
+
+    expect(:hackney, :request, [
+      {[:post, "http://localhost", [], "body", []], {:ok, 200, "headers", :client}}
+    ])
+
+    expect(:hackney, :body, 1, {:ok, "response"})
+
+    assert HTTPoison.post!("localhost", "body") ==
+             %HTTPoison.Response{
+               status_code: 200,
+               headers: "headers",
+               body: "response",
+               request_url: "http://localhost"
+             }
+
+    assert validate(:hackney)
+  end
+
   test "passing ssl option" do
     expect(:hackney, :request, [{[:post, "http://localhost", [], "body", [ssl_options: [certfile: "certs/client.crt"]]],
                                  {:ok, 200, "headers", :client}}])