fix: raise error on empty named param (#183)

snakefmt/parser/syntax.py

@@ -394,6 +394,12 @@ def process_token(self, cur_param: Parameter, prev_token: Token) -> Parameter:
         return cur_param
 
     def flush_param(self, parameter: Parameter, skip_empty: bool = False) -> None:
+        if parameter.has_a_key() and not parameter.has_value():
+            raise NoParametersError(
+                f"{self.line_nb}In {self.keyword_name} definition, "
+                f"keyword {parameter.key}"
+            )
+
         if not parameter.has_value() and skip_empty:
             return
 

tests/test_parser.py

@@ -170,6 +170,17 @@ def test_dictionary_unpacking_passes(self):
         )
         setup_formatter(snake_code)
 
+    def test_key_value_no_value_fails(self):
+        """https://github.com/snakemake/snakefmt/issues/125"""
+        snakecode = (
+            "rule foo:\n"
+            f"{TAB * 1}input:\n"
+            f'{TAB * 2}bar="file.txt",\n'
+            f"{TAB * 2}baz=\n"
+        )
+        with pytest.raises(NoParametersError, match="baz"):
+            setup_formatter(snakecode)
+
 
 class TestIndentationErrors:
     def test_param_collating(self):