From f63dcd93dda1e65c93e4816b212de9bc25b731c2 Mon Sep 17 00:00:00 2001
From: Chris Keathley <c@keathley.io>
Date: Sat, 23 Apr 2016 16:29:40 -0400
Subject: [PATCH] Raise Exception is there is no base_url set

---
 lib/wallaby/exceptions.ex     | 18 ++++++++++++++++++
 lib/wallaby/session.ex        | 23 +++++++++++++++++++----
 test/wallaby/session_test.exs | 15 +++++++++++++++
 3 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/lib/wallaby/exceptions.ex b/lib/wallaby/exceptions.ex
index 45238b08..a727969b 100644
--- a/lib/wallaby/exceptions.ex
+++ b/lib/wallaby/exceptions.ex
@@ -13,3 +13,21 @@ end
 defmodule Wallaby.BadMetadata do
   defexception [:message]
 end
+
+defmodule Wallaby.NoBaseUrl do
+  defexception [:message]
+
+  def exception(relative_path) do
+    msg = """
+    You called visit with #{relative_path}, but did not set a base_url.
+    Set this in config/test.exs or in test/test_helper.exs:
+
+      Application.put_env(:wallaby, :base_url, "http://localhost:4001")
+
+    If using Phoenix, you can use the url from your endpoint:
+
+      Application.put_env(:wallaby, :base_url, YourApplication.Endpoint.url)
+    """
+    %__MODULE__{message: msg}
+  end
+end
diff --git a/lib/wallaby/session.ex b/lib/wallaby/session.ex
index 5b19bf19..ef5e0910 100644
--- a/lib/wallaby/session.ex
+++ b/lib/wallaby/session.ex
@@ -52,12 +52,23 @@ defmodule Wallaby.Session do
 
   @doc """
   Changes the current page to the provided route.
-  Routes are relative to any base url provided.
+  Relative paths are appended to the provided base_url.
+  Absolute paths do not use the base_url.
   """
   @spec visit(t, String.t) :: t
 
   def visit(session, path) do
-    Driver.visit(session, request_url(path))
+    uri = URI.parse(path)
+
+    cond do
+      uri.host == nil && String.length(base_url) == 0 ->
+        raise Wallaby.NoBaseUrl, path
+      uri.host ->
+        Driver.visit(session, path)
+      true ->
+        Driver.visit(session, request_url(path))
+    end
+
     session
   end
 
@@ -142,7 +153,11 @@ defmodule Wallaby.Session do
     session
   end
 
-  defp request_url(url) do
-    (Application.get_env(:wallaby, :base_url) || "") <> url
+  def request_url(path) do
+    base_url <> path
+  end
+
+  defp base_url do
+    Application.get_env(:wallaby, :base_url) || ""
   end
 end
diff --git a/test/wallaby/session_test.exs b/test/wallaby/session_test.exs
index 627a8282..1df8d9cd 100644
--- a/test/wallaby/session_test.exs
+++ b/test/wallaby/session_test.exs
@@ -37,6 +37,21 @@ defmodule Wallaby.SessionTest do
     Application.put_env(:wallaby, :base_url, nil)
   end
 
+  test "visit/2 with a relative url and no base url raises exception", %{session: session, server: server} do
+    assert_raise(Wallaby.NoBaseUrl, fn ->
+      Application.put_env(:wallaby, :base_url, nil)
+      session
+      |> visit("/page_1.html")
+    end)
+  end
+
+  test "visit/2 with an absolute path does not use the base url", %{session: session, server: server} do
+    session
+    |> visit(server.base_url <> "/page_1.html")
+
+    assert has_css?(session, "#visible")
+  end
+
   test "taking screenshots", %{session: session, server: server} do
     node =
       session