test: unreliable swapfile_preserve_recover_spec

Problem:
Test sometimes fails on bsd (cirrus ci):

    test/functional/ex_cmds/swapfile_preserve_recover_spec.lua:589: retry() attempts: 464
    test/functional/ex_cmds/swapfile_preserve_recover_spec.lua:590: Expected objects to be the same.
    Passed in:
    (table: 0x0d5f1aa44070) {
      [1] = ''
     *[2] = ''
      [3] = '[Process exited 1]' }
    Expected:
    (table: 0x0d5ea3eb8718) {
      [1] = ''
     *[2] = '[Process exited 1]'
      [3] = '' }
    stack traceback:
      test/testutil.lua:104: in function 'retry'
      test/functional/ex_cmds/swapfile_preserve_recover_spec.lua:589: in function <test/functional/ex_cmds/swapfile_preserve_recover_spec.lua:556>

Solution:
Filter out empty items to avoid irrelevant redraw-timing assumptions.

1 files changed, 6 insertions, 1 deletions

diff --git a/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua b/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
index 38e6707a3b..8eec02524e 100644
--- a/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
+++ b/test/functional/ex_cmds/swapfile_preserve_recover_spec.lua
@@ -152,6 +152,9 @@ describe('swapfile detection', function()
 
   it('redrawing during prompt does not break treesitter', function()
     local testfile = 'Xtest_swapredraw.lua'
+    finally(function()
+      os.remove(testfile)
+    end)
     write_file(
       testfile,
       [[
@@ -589,7 +592,9 @@ describe('quitting swapfile dialog on startup stops TUI properly', function()
     retry(nil, nil, function()
       eq(
         { '[Process exited 1]' },
-        eval("[1, 2, '$']->map({_, lnum -> getline(lnum)->trim(' ', 2)})->filter({_, s -> !empty(trim(s))})")
+        eval(
+          "[1, 2, '$']->map({_, lnum -> getline(lnum)->trim(' ', 2)})->filter({_, s -> !empty(trim(s))})"
+        )
       )
     end)
   end)