fix(test): backup/restore fparam.npy in TestFparam instead of deleting

TestFparam.tearDown deleted the committed fparam.npy, breaking other
tests (e.g. test_fitting_stat) running later in the same CI shard.
Also revert the unnecessary .resolve() workaround in test_fitting_stat.

Author: Han Wang

source/tests/pt/test_training.py

@@ -268,11 +268,22 @@ def setUp(self) -> None:
         self.config["training"]["numb_steps"] = 1
         self.config["training"]["save_freq"] = 1
         self.set_path = Path(__file__).parent / "water/data/data_0" / "set.000"
-        shutil.copyfile(self.set_path / "energy.npy", self.set_path / "fparam.npy")
+        # Backup the committed fparam.npy (numb_fparam=2) before overwriting
+        # with a 1-column version for this test.
+        self._fparam_backup = self.set_path / "fparam.npy.bak"
+        fparam_path = self.set_path / "fparam.npy"
+        if fparam_path.exists():
+            shutil.copyfile(fparam_path, self._fparam_backup)
+        shutil.copyfile(self.set_path / "energy.npy", fparam_path)
         self.config["model"]["data_stat_nbatch"] = 100
 
     def tearDown(self) -> None:
-        (self.set_path / "fparam.npy").unlink(missing_ok=True)
+        # Restore the original fparam.npy so other tests can use it.
+        fparam_path = self.set_path / "fparam.npy"
+        if self._fparam_backup.exists():
+            shutil.move(str(self._fparam_backup), str(fparam_path))
+        else:
+            fparam_path.unlink(missing_ok=True)
         DPTrainTest.tearDown(self)
 
 

source/tests/pt_expt/fitting/test_fitting_stat.py

@@ -117,18 +117,13 @@ def _get_weighted_fitting_stat(
     return weighted_avg, weighted_std
 
 
-# Paths to the water data used by PT tests.
-# resolve() follows the ``pt/water -> model/water`` symlink so numpy can
-# always open the real file, even on CI runners where symlink handling
-# can be fragile.
-_PT_DATA = str(
-    (Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "data_0").resolve()
-)
+# Paths to the water data used by PT tests
+_PT_DATA = str(Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "data_0")
 _PT_DATA_NO_FPARAM = str(
-    (Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "data_1").resolve()
+    Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "data_1"
 )
 _PT_DATA_SINGLE = str(
-    (Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "single").resolve()
+    Path(__file__).parent.parent.parent / "pt" / "water" / "data" / "single"
 )
 
 _descriptor_se_e2_a = {