Improve comment patching + state variable constant patching

slither/tools/slither_format/formatters/constable_states.py

@@ -1,10 +1,12 @@
 import re
-from ..exceptions import FormatError
+from ..exceptions import FormatError, FormatImpossible
 from ..utils.patches import create_patch
 
 def format(slither, result):
     elements = result['elements']
     for element in elements:
+        if not element.expression:
+            raise FormatImpossible(f'{element.name} is uninitialized and cannot become constant.')
         _patch(slither, result, element['source_mapping']['filename_absolute'],
                element['name'],
                "constant " + element['name'],

slither/tools/slither_format/formatters/naming_convention.py

@@ -338,17 +338,17 @@ def _explore_variables_declaration(slither, variables, result, target, convert,
             # Patch comment only makes sense for local variable declaration in the parameter list
             if patch_comment and isinstance(variable, LocalVariable):
                 if 'lines' in variable.source_mapping and variable.source_mapping['lines']:
-                    end_line = variable.source_mapping['lines'][0]
                     func = variable.function
+                    end_line = func.source_mapping['lines'][0]
                     if variable in func.parameters:
-                        idx = len(func.parameters) - func.parameters.index(variable)
+                        idx = len(func.parameters) - func.parameters.index(variable) + 1
                         first_line = end_line - idx - 2
 
                         potential_comments = slither.source_code[filename_source_code].encode('utf8')
                         potential_comments = potential_comments.splitlines(keepends=True)[first_line:end_line-1]
 
-                        idx_beginning = variable.source_mapping['start']
-                        idx_beginning +=  - variable.source_mapping['starting_column'] + 1
+                        idx_beginning = func.source_mapping['start']
+                        idx_beginning +=  - func.source_mapping['starting_column'] + 1
                         idx_beginning +=  - sum([len(c) for c in potential_comments])
 
                         old_comment = f'@param {old_str}'.encode('utf8')