Make sure return format is valid. Otherwise raise Valueerror. #1614

pre-commit

@@ -8,23 +8,16 @@
 # To enable this hook, rename this file to "pre-commit".
 
 status=0
-files=$(git diff --diff-filter=d --cached --name-only | grep -E 'pymatgen.*\.(py)$' | sed '/test_/d')
+files=$(git diff --diff-filter=d --cached --name-only | grep -E 'monty.*\.(py)$' | sed '/test_/d')
 files=`echo $files | tr '\n' ' '`
-echo "Check code styles for $files"
-pycodestyle pymatgen/dao.py $files
-if [ $? -ne 0 ]; then
-  echo "Bad code style detected by pycodestyle. Fix before commit."
-  exit 1
-fi
-echo "Flake8 for $files"
-flake8 pymatgen/dao.py $files
-if [ $? -ne 0 ]; then
-  echo "Bad code style detected by flake8. Fix before commit."
-  exit 1
-fi
-echo "Check doc styles for $files"
-pydocstyle --match='(?!test_).*\.py' pymatgen/dao.py $files
-if [ $? -ne 0 ]; then
-  echo "Bad doc style detected. Fix before commit."
-  exit 1
-fi
+if [ "$files" != " " ]; then
+    for cmd in pycodestyle mypy flake8 pydocstyle
+    do
+        echo "Running $cmd $files..."
+        $cmd $files
+        if [ $? -ne 0 ]; then
+            echo "$cmd failed. Fix before commit."
+            exit 1
+        fi
+    done
+fi

pymatgen/core/structure.py

@@ -1871,13 +1871,15 @@ def to(self, fmt=None, filename=None, **kwargs):
             from pymatgen.io.prismatic import Prismatic
             s = Prismatic(self).to_string()
             return s
-        else:
+        elif fmt == "yaml" or fnmatch(fname, "*.yaml*") or fnmatch(fname, "*.yml*"):
             import ruamel.yaml as yaml
             if filename:
                 with zopen(filename, "wt") as f:
                     yaml.safe_dump(self.as_dict(), f)
                 return None
             return yaml.safe_dump(self.as_dict())
+        else:
+            raise ValueError("Invalid format.")
 
         if filename:
             writer.write_file(filename)

pymatgen/core/tests/test_structure.py

@@ -518,6 +518,9 @@ def test_to_from_file_string(self):
         s = Structure.from_file("Si_testing.yaml")
         self.assertEqual(s, self.struct)
 
+        self.assertRaises(ValueError, self.struct.to, filename="whatever")
+        self.assertRaises(ValueError, self.struct.to, fmt="badformat")
+
         # Test Path support.
         s = Structure.from_file(Path("Si_testing.yaml"))
         self.assertEqual(s, self.struct)