Do not crash on completions in untitled: schema

Fixes #732

apps/language_server/lib/language_server/server.ex

@@ -695,6 +695,12 @@ defmodule ElixirLS.LanguageServer.Server do
 
     signature_after_complete = Map.get(state.settings || %{}, "signatureAfterComplete", true)
 
+    path =
+      case uri do
+        "file:" <> _ -> SourceFile.path_from_uri(uri)
+        _ -> nil
+      end
+
     fun = fn ->
       Completion.completion(source_file.text, line, character,
         snippets_supported: snippets_supported,
@@ -703,7 +709,7 @@ defmodule ElixirLS.LanguageServer.Server do
         signature_help_supported: signature_help_supported,
         locals_without_parens: locals_without_parens,
         signature_after_complete: signature_after_complete,
-        file_path: SourceFile.path_from_uri(uri)
+        file_path: path
       )
     end
 

apps/language_server/test/providers/completion_test.exs

@@ -962,6 +962,34 @@ defmodule ElixirLS.LanguageServer.Providers.CompletionTest do
                "insertText" => "defmodule $1 do\n\t$0\nend"
              } = first
     end
+
+    test "will suggest defmodule without module_name snippet when file path is nil" do
+      text = """
+      defmod
+      #     ^
+      """
+
+      {line, char} = {0, 6}
+
+      TestUtils.assert_has_cursor_char(text, line, char)
+
+      assert {:ok, %{"items" => [first | _] = _items}} =
+               Completion.completion(
+                 text,
+                 line,
+                 char,
+                 @supports
+                 |> Keyword.put(
+                   :file_path,
+                   nil
+                 )
+               )
+
+      assert %{
+               "label" => "defmodule",
+               "insertText" => "defmodule $1 do\n\t$0\nend"
+             } = first
+    end
   end
 
   describe "generic suggestions" do