DEV: Move spec/components to spec/lib (#15987)

Lib specs were inexplicably split into two directories (`lib` and `components`)

This moves them all into `lib`.

spec/lib/directory_helper_spec.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe DirectoryHelper do
+  class DummyClass
+    include DirectoryHelper
+  end
+  let(:helper) { DummyClass.new }
+
+  before do
+    helper.tmp_directory('prefix')
+    helper.tmp_directory('other_prefix')
+  end
+
+  after do
+    helper.remove_tmp_directory('prefix')
+    helper.remove_tmp_directory('other_prefix')
+  end
+
+  describe '#tmp_directory' do
+    it 'is memoized by prefix' do
+      expect(helper.tmp_directory('prefix')).to eq(helper.tmp_directory('prefix'))
+      expect(helper.tmp_directory('prefix')).not_to eq(helper.tmp_directory('other_prefix'))
+    end
+  end
+
+  describe '#remove_tmp_directory' do
+    it 'removes the prefixed directory from the filesystem' do
+      tmp_directory = helper.tmp_directory('prefix')
+      helper.remove_tmp_directory('prefix')
+
+      expect(Dir[tmp_directory]).not_to be_present
+    end
+  end
+end