Additional test cases for Files#can_download_as_zip (#4019)

* Implement tests for directory size limit

* Make minor stylistic adjustments

* Add test case for unauthorized directory

* Stub file size calculation

* Rename file_size to dir_size

* Add tests for timeout and calculation error

* Remove size-within-limit test

apps/dashboard/test/models/files_test.rb

@@ -39,11 +39,42 @@ class FilesTest < ActiveSupport::TestCase
       error_msg = 'some failure message'
       Open3.stubs(:capture3).returns(["blarg \n 28d", error_msg, exit_failure])
       result = PosixFile.new(dir).can_download_as_zip?
+      error = I18n.t('dashboard.files_directory_size_unknown', exit_code: '1', error: error_msg)
 
-      assert_equal([false, I18n.t('dashboard.files_directory_size_unknown', exit_code: '1', error: error_msg)], result)
+      assert_equal [false, error], result
     end 
   end
 
+  test "can_download_as_zip handles unauthorized directory" do
+    Dir.mktmpdir do |dir|
+      FileUtils.chmod(0400, dir)  # Read-only permission
+      result = PosixFile.new(dir).can_download_as_zip?
+      error = I18n.t('dashboard.files_directory_download_unauthorized')
+
+      assert_equal [false, error], result
+    end
+  end
+
+  test "can_download_as_zip handles directory size calculation timeout" do
+    Dir.mktmpdir do |dir|
+      Open3.stubs(:capture3).returns(["", "Timeout", exit_failure(124)])
+      result = PosixFile.new(dir).can_download_as_zip?
+      error = I18n.t('dashboard.files_directory_size_calculation_timeout')
+
+      assert_equal [false, error], result
+    end
+  end
+
+  test "can_download_as_zip handles directory size calculation error" do
+    Dir.mktmpdir do |dir|
+      Open3.stubs(:capture3).returns(["", "", exit_success])
+      result = PosixFile.new(dir).can_download_as_zip?
+      error = I18n.t('dashboard.files_directory_size_calculation_error')
+
+      assert_equal [false, error], result
+    end
+  end
+
   test "can_download_as_zip handles files sizes of 0" do
     Dir.mktmpdir do |dir|
       Open3.stubs(:capture3).returns(["0 /dev
@@ -53,6 +84,21 @@ class FilesTest < ActiveSupport::TestCase
     end 
   end
 
+  test "can_download_as_zip handles directory size exceeding limit" do
+    download_directory_size_limit = Configuration.file_download_dir_max
+    Dir.mktmpdir do |dir|
+      dir_size = download_directory_size_limit + 1
+      PosixFile.any_instance.stubs(:calculate_directory_size)
+        .returns(download_directory_size_limit + 1)
+      Open3.stubs(:capture3).returns(["#{dir_size} #{dir} 
+        \n #{dir_size} total", "", exit_success])
+      result = PosixFile.new(dir).can_download_as_zip?
+      error = I18n.t('dashboard.files_directory_too_large', download_directory_size_limit: download_directory_size_limit)
+
+      assert_equal([false, error], result)
+    end 
+  end
+
   test "Ensuring PosixFile.username(uid) returns string" do
     assert_equal "9999999", PosixFile.username(9999999)
   end