Fix FileManager unit test cases for macOS (symlinked TMPDIR)

tfw/components/ide/file_manager/test_file_manager.py

@@ -2,7 +2,7 @@
 from dataclasses import dataclass
 from secrets import token_urlsafe
 from os import mkdir, symlink
-from os.path import join
+from os.path import join, realpath
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
@@ -42,6 +42,7 @@ def generate_name():
 @pytest.fixture()
 def context():
     with TemporaryDirectory() as workdir:
+        workdir = realpath(workdir)  # macOS uses a symlinked TMPDIR
         subdir = join(workdir, generate_name())
         subfile = join(subdir, generate_name() + '.txt')
         mkdir(subdir)