fix: return a descriptive error for relative URLs instead of a CaseClauseError (#504)

---------

Co-authored-by: Ricardo Trindade <ricardo.trindade743@gmail.com>
Co-authored-by: Eduardo Gurgel Pinho <eduardo@gurgel.me>

Author: 3 people

lib/httpoison/base.ex

@@ -707,6 +707,24 @@ defmodule HTTPoison.Base do
     end
   end
 
+  @doc false
+  defp validate_request_url(url) do
+    url = to_string(url)
+
+    %{scheme: scheme, host: host} = URI.parse(url)
+
+    cond do
+      is_nil(scheme) ->
+        {:error, "Invalid URL: #{url} (missing scheme e.g. http:// or https:// or http+unix://)"}
+
+      is_nil(host) or host == "" ->
+        {:error, "Invalid URL: #{url} (missing host)"}
+
+      true ->
+        :ok
+    end
+  end
+
   @doc false
   def default_process_request_url(url) do
     case url |> String.slice(0, 12) |> String.downcase() do
@@ -877,59 +895,65 @@ defmodule HTTPoison.Base do
         process_response_body,
         process_response
       ) do
-    hn_proxy_options = build_hackney_proxy_options(request)
-    hn_options = hn_proxy_options ++ build_hackney_options(module, request)
-
-    case do_request(request, hn_options) do
-      {:ok, status_code, headers} ->
-        response(
-          process_response_status_code,
-          process_response_headers,
-          process_response_body,
-          process_response,
-          status_code,
-          headers,
-          "",
-          request
-        )
+    case validate_request_url(request.url) do
+      :ok ->
+        hn_proxy_options = build_hackney_proxy_options(request)
+        hn_options = hn_proxy_options ++ build_hackney_options(module, request)
 
-      {:ok, status_code, headers, client} ->
-        max_length = Keyword.get(request.options, :max_body_length, :infinity)
-
-        case :hackney.body(client, max_length) do
-          {:ok, body} ->
+        case do_request(request, hn_options) do
+          {:ok, status_code, headers} ->
             response(
               process_response_status_code,
               process_response_headers,
               process_response_body,
               process_response,
               status_code,
               headers,
-              body,
+              "",
+              request
+            )
+
+          {:ok, status_code, headers, client} ->
+            max_length = Keyword.get(request.options, :max_body_length, :infinity)
+
+            case :hackney.body(client, max_length) do
+              {:ok, body} ->
+                response(
+                  process_response_status_code,
+                  process_response_headers,
+                  process_response_body,
+                  process_response,
+                  status_code,
+                  headers,
+                  body,
+                  request
+                )
+
+              {:error, reason} ->
+                {:error, %Error{reason: reason}}
+            end
+
+          {:ok, {:maybe_redirect, status_code, headers, _client}} ->
+            maybe_redirect(
+              process_response_status_code,
+              process_response_headers,
+              status_code,
+              headers,
               request
             )
 
+          {:ok, id} ->
+            {:ok, %HTTPoison.AsyncResponse{id: id}}
+
           {:error, reason} ->
             {:error, %Error{reason: reason}}
-        end
 
-      {:ok, {:maybe_redirect, status_code, headers, _client}} ->
-        maybe_redirect(
-          process_response_status_code,
-          process_response_headers,
-          status_code,
-          headers,
-          request
-        )
-
-      {:ok, id} ->
-        {:ok, %HTTPoison.AsyncResponse{id: id}}
+          {:connect_error, {:error, reason}} ->
+            {:error, %Error{reason: reason}}
+        end
 
       {:error, reason} ->
         {:error, %Error{reason: reason}}
-
-      {:connect_error, {:error, reason}} ->
-        {:error, %Error{reason: reason}}
     end
   end
 

mix.exs

@@ -7,7 +7,7 @@ defmodule HTTPoison.Mixfile do
   def project do
     [
       app: :httpoison,
-      version: "2.2.3",
+      version: "2.3.0",
       elixir: "~> 1.11",
       name: "HTTPoison",
       description: @description,

test/httpoison_base_test.exs

@@ -749,4 +749,25 @@ defmodule HTTPoisonBaseTest do
     assert HTTPoison.request(:get, "http://localhost") ==
              {:error, %HTTPoison.Error{reason: reason}}
   end
+
+  test "invalid url raises error for missing or empty host" do
+    invalid_urls = ["http://", "http:///path"]
+
+    for url <- invalid_urls do
+      assert_raise HTTPoison.Error, "\"Invalid URL: #{url} (missing host)\"", fn ->
+        HTTPoison.get!(url)
+      end
+    end
+  end
+
+  test "invalid url returns error for missing or empty host" do
+    invalid_urls = ["http://", "http:///path"]
+
+    for url <- invalid_urls do
+      # assert_raise HTTPoison.Error, "\"Invalid URL: #{url} (missing host)\"", fn ->
+      assert {:error, %HTTPoison.Error{reason: error}} = HTTPoison.get(url)
+      assert error =~ "Invalid URL:"
+      # end
+    end
+  end
 end