Handle providers listed with subdomains

host_matches? previously would fail to match providers with URLs such
as http://www.twitter.com/. Generalized the regex to handle subdomains.

lib/furlex/oembed.ex

@@ -16,22 +16,24 @@ defmodule Furlex.Oembed do
   Soft fetch will fetch cached providers. Hard fetch requests
   providers from oembed.com and purges the cache.
   """
-  @spec fetch_providers(Atom.t) :: {:ok, List.t} | {:error, Atom.t}
+  @spec fetch_providers(Atom.t()) :: {:ok, List.t()} | {:error, Atom.t()}
   def fetch_providers(type \\ :soft)
+
   def fetch_providers(:hard) do
     case get("/providers.json") do
       {:ok, %{body: providers}} ->
-        GenServer.cast __MODULE__, {:providers, providers}
+        GenServer.cast(__MODULE__, {:providers, providers})
         {:ok, providers}
 
-      other                ->
-        Logger.error "Could not fetch providers: #{inspect other}"
+      other ->
+        Logger.error("Could not fetch providers: #{inspect(other)}")
         {:error, :fetch_error}
     end
   end
+
   def fetch_providers(_soft) do
     case GenServer.call(__MODULE__, :providers) do
-      nil       -> fetch_providers(:hard)
+      nil -> fetch_providers(:hard)
       providers -> {:ok, providers}
     end
   end
@@ -47,10 +49,10 @@ defmodule Furlex.Oembed do
     iex> Oembed.endpoint_from_url "https://vimeo.com/88856141", %{"format" => "xml"}
     {:ok, "https://vimeo.com/api/oembed.xml"}
   """
-  @spec endpoint_from_url(String.t, Map.t) :: {:ok, String.t} | {:error, Atom.t}
+  @spec endpoint_from_url(String.t(), Map.t()) :: {:ok, String.t()} | {:error, Atom.t()}
   def endpoint_from_url(url, params \\ %{"format" => "json"}, opts \\ []) do
     case provider_from_url(url, opts) do
-      nil      ->
+      nil ->
         {:error, :no_oembed_provider}
 
       provider ->
@@ -60,39 +62,38 @@ defmodule Furlex.Oembed do
 
   # Maps a url to a provider, or returns nil if no such provider exists
   defp provider_from_url(url, opts) do
-    fetch_type =
-      if Keyword.get(opts, :skip_cache?, false), do: :hard, else: :soft
+    fetch_type = if Keyword.get(opts, :skip_cache?, false), do: :hard, else: :soft
 
     {:ok, providers} = fetch_providers(fetch_type)
 
     case URI.parse(url) do
-      %URI{host: nil}  ->
+      %URI{host: nil} ->
         nil
 
       %URI{host: host} ->
-        Enum.find providers, &host_matches?(host, &1)
+        Enum.find(providers, &host_matches?(host, &1))
     end
   end
 
   defp endpoint_from_provider(provider, params) do
-    [ endpoint | _] = provider["endpoints"]
+    [endpoint | _] = provider["endpoints"]
 
-    url   = endpoint["url"]
+    url = endpoint["url"]
     regex = ~r/{(.*?)}/
-    url   = Regex.replace regex, url, fn _, key -> params[key] end
+    url = Regex.replace(regex, url, fn _, key -> params[key] end)
 
     {:ok, url}
   end
 
   defp host_matches?(host, %{"provider_url" => provider_url}) do
-    Regex.match? ~r/https?:\/\/#{host}/, provider_url
+    Regex.match?(~r/https?:\/\/([a-zA-Z0-9]+\.)?#{host}/, provider_url)
   end
 
   ## GenServer callbacks
 
   @doc false
   def start_link(opts \\ []) do
-    GenServer.start_link __MODULE__, nil, opts
+    GenServer.start_link(__MODULE__, nil, opts)
   end
 
   def init(state) do

test/fixtures/providers.json

@@ -1,4 +1,17 @@
 [
+  {
+    "provider_name": "Twitter",
+    "provider_url": "http:\/\/www.twitter.com/",
+    "endpoints": [
+      {
+        "schemes": [
+          "https:\/\/twitter.com\/*\/status\/*",
+          "https:\/\/*.twitter.com\/*\/status\/*"
+        ],
+        "url": "https:\/\/publish.twitter.com\/oembed"
+      }
+    ]
+  },
   {
     "provider_name": "VideoJug",
     "provider_url": "http:\/\/www.videojug.com",
@@ -147,4 +160,4 @@
       }
     ]
   }
-]
+]

test/furlex/oembed_test.exs

@@ -5,35 +5,49 @@ defmodule Furlex.OembedTest do
 
   setup do
     bypass = Bypass.open()
-    url    = "http://localhost:#{bypass.port}"
-    config = Application.get_env :furlex, Oembed, []
+    url = "http://localhost:#{bypass.port}"
+    config = Application.get_env(:furlex, Oembed, [])
 
-    new_config = Keyword.put config, :oembed_host, url
-    Application.put_env :furlex, Oembed, new_config
+    new_config = Keyword.put(config, :oembed_host, url)
+    Application.put_env(:furlex, Oembed, new_config)
 
-    on_exit fn ->
-      Application.put_env :furlex, Oembed, config
+    on_exit(fn ->
+      Application.put_env(:furlex, Oembed, config)
 
       :ok
-    end
+    end)
 
     {:ok, bypass: bypass}
   end
 
   test "returns endpoint from url", %{bypass: bypass} do
-    Bypass.expect bypass, &handle/1
+    Bypass.expect(bypass, &handle/1)
 
     assert {:error, :no_oembed_provider} ==
-      Oembed.endpoint_from_url("foobar")
+             Oembed.endpoint_from_url("foobar")
 
-    url    = "https://vimeo.com/88856141"
+    url = "https://vimeo.com/88856141"
     params = %{"format" => "json"}
 
-    {:ok, endpoint} = Oembed.endpoint_from_url(url, params, [skip_cache?: true])
+    {:ok, endpoint} = Oembed.endpoint_from_url(url, params, skip_cache?: true)
 
     assert endpoint == "https://vimeo.com/api/oembed.json"
   end
 
+  test "returns endpoint from url with subdomain", %{bypass: bypass} do
+    Bypass.expect(bypass, &handle/1)
+
+    assert {:error, :no_oembed_provider} ==
+             Oembed.endpoint_from_url("foobar")
+
+    url = "https://twitter.com/arshia__/status/1204481088422178817?s=20"
+    params = %{"format" => "json"}
+
+    {:ok, endpoint} = Oembed.endpoint_from_url(url, params, skip_cache?: true)
+
+    assert endpoint == "https://publish.twitter.com/oembed"
+  end
+
   def handle(%{request_path: "/providers.json"} = conn) do
     assert conn.method == "GET"
 
@@ -42,6 +56,6 @@ defmodule Furlex.OembedTest do
       |> Path.join()
       |> File.read!()
 
-    Plug.Conn.resp conn, 200, providers
+    Plug.Conn.resp(conn, 200, providers)
   end
 end