Move from Helpers to Utils and add doctests

lib/livebook/utils.ex

@@ -369,6 +369,33 @@ defmodule Livebook.Utils do
     |> Enum.join("\n")
   end
 
+  @doc """
+  Returns a URL (including localhost) to import the given `url` as a notebook.
+
+      iex> Livebook.Utils.notebook_import_url("https://example.com/foo.livemd")
+      "http://localhost:4002/import?url=https%3A%2F%2Fexample.com%2Ffoo.livemd"
+
+      iex> Livebook.Utils.notebook_import_url("https://my_host", "https://example.com/foo.livemd")
+      "https://my_host/import?url=https%3A%2F%2Fexample.com%2Ffoo.livemd"
+
+  """
+  def notebook_import_url(base_url \\ LivebookWeb.Endpoint.access_struct_url(), url) do
+    base_url
+    |> URI.parse()
+    |> Map.replace!(:path, "/import")
+    |> append_query("url=#{URI.encode_www_form(url)}")
+    |> URI.to_string()
+  end
+
+  # TODO: On Elixir v1.14, use URI.append_query/2
+  defp append_query(%URI{query: query} = uri, query_to_add) when query in [nil, ""] do
+    %{uri | query: query_to_add}
+  end
+
+  defp append_query(%URI{} = uri, query) do
+    %{uri | query: uri.query <> "&" <> query}
+  end
+
   @doc """
   Formats the given number of bytes into a human-friendly text.
 

lib/livebook_app.ex

@@ -84,7 +84,8 @@ if Mix.target() == :app do
     end
 
     defp import_livebook(url) do
-      LivebookWeb.Helpers.notebook_import_url(url)
+      url
+      |> Livebook.Utils.notebook_import_url()
       |> Livebook.Utils.browser_open()
     end
 

lib/livebook_cli/server.ex

@@ -135,7 +135,7 @@ defmodule LivebookCLI.Server do
 
   defp open_from_options(base_url, _opts, [url]) do
     base_url
-    |> LivebookWeb.Helpers.notebook_import_url(url)
+    |> Livebook.Utils.notebook_import_url(url)
     |> Livebook.Utils.browser_open()
   end
 

lib/livebook_web/helpers.ex

@@ -376,26 +376,6 @@ defmodule LivebookWeb.Helpers do
   def file_system_label(%FileSystem.Local{}), do: "Local disk"
   def file_system_label(%FileSystem.S3{} = fs), do: fs.bucket_url
 
-  @doc """
-  Returns a URL (including localhost) to import the given `url` as a notebook.
-  """
-  def notebook_import_url(base_url \\ LivebookWeb.Endpoint.access_struct_url(), url) do
-    base_url
-    |> URI.parse()
-    |> Map.replace!(:path, "/import")
-    |> append_query("url=#{URI.encode_www_form(url)}")
-    |> URI.to_string()
-  end
-
-  # TODO: On Elixir v1.14, use URI.append_query/2
-  defp append_query(%URI{query: query} = uri, query_to_add) when query in [nil, ""] do
-    %{uri | query: query_to_add}
-  end
-
-  defp append_query(%URI{} = uri, query) do
-    %{uri | query: uri.query <> "&" <> query}
-  end
-
   @doc """
   Returns the text in singular or plural depending on the quantity