Fix: preserve absolute Path object for tfdir

- Ensure `_abspath` returns the original `Path` object when it's absolute, reverting the modernization regression.

- Cast `self.tfdir` to `str` before encoding to prevent `AttributeError` when cache is enabled.

- Add test cases to verify both behaviors.

Author: ludoo

test/test_tfdir_path.py

@@ -0,0 +1,17 @@
+import tempfile
+from pathlib import Path
+import tftest
+
+def test_tfdir_as_path():
+  with tempfile.TemporaryDirectory() as tmpdir:
+    tmpdir_path = Path(tmpdir).resolve()
+    tf = tftest.TerraformTest(tmpdir_path)
+    # The regression: tf.tfdir / 'something' throws TypeError
+    # if tf.tfdir is converted to a string.
+    assert (tf.tfdir / 'something') == tmpdir_path / 'something'
+
+def test_tfdir_as_str():
+  with tempfile.TemporaryDirectory() as tmpdir:
+    tf = tftest.TerraformTest(tmpdir)
+    assert isinstance(tf.tfdir, str)
+

tftest.py

@@ -349,7 +349,7 @@ def _abspath(self, path):
     """Make relative path absolute from base dir."""
     path_obj = Path(path)
     if path_obj.is_absolute():
-      return str(path_obj)
+      return path
     return str(Path(self._basedir) / path)
 
   def _dirhash(self, directory, hash, ignore_hidden=False,
@@ -429,7 +429,7 @@ def cache(self, **kwargs):
         return func(self, **kwargs)
 
       cache_dir = self.cache_dir / \
-          Path(sha1(self.tfdir.encode("cp037")).hexdigest()) / \
+          Path(sha1(str(self.tfdir).encode("cp037")).hexdigest()) / \
           Path(func.__name__)
       cache_dir.mkdir(parents=True, exist_ok=True)