fix: Empty json cannot be fixed (#43)

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

Author: phuongfi91

src/nitpick/blender.py

@@ -673,7 +673,8 @@ def load(self) -> bool:
         if self.path is not None:
             self._string = Path(self.path).read_text(encoding="UTF-8")
         if self._string is not None:
-            self._object = flatten_quotes(json.loads(self._string))
+            s = self._string.strip() or "{}"  # preventive measure for empty file
+            self._object = flatten_quotes(json.loads(s))
         if self._object is not None:
             # Every file should end with a blank line
             self._reformatted = json.dumps(self._object, sort_keys=True, indent=2) + "\n"

src/nitpick/plugins/json.py

@@ -59,7 +59,7 @@ def enforce_rules(self) -> Iterator[Fuss]:
                 self.report(SharedViolations.MISSING_VALUES, blender, comparison.missing),
             )
 
-        if self.autofix and self.dirty and blender:
+        if self.autofix and self.dirty and blender is not None:
             self.file_path.write_text(JsonDoc(obj=unflatten_quotes(blender)).reformatted)
 
     def expected_dict_from_contains_keys(self):
@@ -86,7 +86,7 @@ def report(self, violation: ViolationEnum, blender: JsonDict, change: BaseDoc |
         """Report a violation while optionally modifying the JSON dict."""
         if not change:
             return
-        if blender:
+        if blender is not None:
             if violation == SharedViolations.MISSING_VALUES:
                 self._update_missing_values(blender, change)
             else:

tests/test_json.py

@@ -356,3 +356,41 @@ def test_jsonfile_deprecated(tmp_path):
         )
         assert len(filtered) == 1
         assert issubclass(filtered[0].category, DeprecationWarning)
+
+
+def test_missing_value_should_be_added_to_empty_json_file_with_no_keys(tmp_path):
+    """Missing value should be added to empty json file with just "{}"."""
+    ProjectMock(tmp_path).style(
+        """
+        ["my.json".contains_json]
+        "some_key" = \"\"\"
+            "some_value"
+        \"\"\"
+        """
+    ).save_file("my.json", """{}""").api_fix().assert_file_contents(
+        "my.json",
+        """
+        {
+          "some_key": "some_value"
+        }
+        """,
+    )
+
+
+def test_missing_value_should_be_added_to_completely_empty_json_file(tmp_path):
+    """Missing value should be added to completely empty json file."""
+    ProjectMock(tmp_path).style(
+        """
+        ["my.json".contains_json]
+        "some_key" = \"\"\"
+            "some_value"
+        \"\"\"
+        """
+    ).save_file("my.json", "\n").api_fix().assert_file_contents(
+        "my.json",
+        """
+        {
+          "some_key": "some_value"
+        }
+        """,
+    )