Convert should_format? test to use format/3 and fixtures

This function is really an implementation detail, so let’s test the
public API.

The function also relies on interaction with the filesystem, so testing
without fixtures is a bad idea because it will lead to incorrect
results.

Author: jonleighton

apps/language_server/lib/language_server/providers/formatting.ex

@@ -53,7 +53,7 @@ defmodule ElixirLS.LanguageServer.Providers.Formatting do
 
   defp can_format?(_uri, _project_dir), do: false
 
-  def should_format?(file_uri, project_dir, inputs) when is_list(inputs) do
+  defp should_format?(file_uri, project_dir, inputs) when is_list(inputs) do
     file_path = file_uri |> SourceFile.abs_path_from_uri()
 
     inputs
@@ -67,7 +67,7 @@ defmodule ElixirLS.LanguageServer.Providers.Formatting do
     |> Enum.any?(&(file_path == &1))
   end
 
-  def should_format?(_file_uri, _project_dir, _inputs), do: true
+  defp should_format?(_file_uri, _project_dir, _inputs), do: true
 
   defp myers_diff_to_text_edits(myers_diff) do
     myers_diff_to_text_edits(myers_diff, {0, 0}, [])

apps/language_server/test/fixtures/formatter/.formatter.exs

@@ -1,4 +1,7 @@
 [
   line_length: 20,
-  subdirectories: ["lib"]
+  subdirectories: [
+    "lib",
+    "test"
+  ]
 ]

apps/language_server/test/fixtures/formatter/test/.formatter.exs

@@ -0,0 +1,3 @@
+[
+  inputs: ["**/*.exs"]
+]

apps/language_server/test/providers/formatting_test.exs

@@ -474,18 +474,38 @@ defmodule ElixirLS.LanguageServer.Providers.FormattingTest do
     end)
   end
 
+  @tag :fixture
   test "honors :inputs when deciding to format" do
-    file = __ENV__.file
-    uri = SourceFile.path_to_uri(file)
-    project_dir = Path.dirname(file)
+    in_fixture(Path.join(__DIR__, ".."), "formatter", fn ->
+      project_dir = Path.expand(".")
+
+      assert_formatted("file.ex", project_dir)
+
+      # test/.formatter.exs has [inputs: ["**/*.exs"]]
+      assert_formatted("test/file.exs", project_dir)
+      refute_formatted("test/file.ex", project_dir)
+    end)
+  end
+
+  def assert_formatted(path, project_dir) do
+    assert {:ok, [%{}]} = format(path, project_dir)
+  end
+
+  def refute_formatted(path, project_dir) do
+    assert {:ok, []} = format(path, project_dir)
+  end
 
-    opts = []
-    assert Formatting.should_format?(uri, project_dir, opts[:inputs])
+  defp format(path, project_dir) do
+    project_dir = maybe_convert_path_separators(project_dir)
+    path = maybe_convert_path_separators("#{project_dir}/#{path}")
 
-    opts = [inputs: ["*.exs"]]
-    assert Formatting.should_format?(uri, project_dir, opts[:inputs])
+    source_file = %SourceFile{
+      text: "",
+      version: 1,
+      dirty?: true
+    }
 
-    opts = [inputs: ["*.ex"]]
-    refute Formatting.should_format?(uri, project_dir, opts[:inputs])
+    File.write!(path, "")
+    Formatting.format(source_file, SourceFile.path_to_uri(path), project_dir)
   end
 end