Merge pull request #9 from tm-a-t/filter-code

Fix false positive code detections as described in #4

app/handlers/__init__.py

@@ -4,7 +4,7 @@
 from app import client, message_design
 from app.handlers.uitls import _handle_errors, outgoing_messages_filter
 from app.run_code.parse_code import parse_code
-from app.run_code import eval_message
+from app.run_code import eval_message, get_kwargs
 
 
 async def handle_message(message: Message) -> None:
@@ -17,7 +17,9 @@ async def handle_message(message: Message) -> None:
         await message.edit(message.text[2:])
         return
 
-    res = parse_code(raw_text)
+    locals_ = get_kwargs()
+
+    res = parse_code(raw_text, locals_)
     if not res.is_code:
         return
 

app/run_code/__init__.py

@@ -8,6 +8,10 @@
 from app.run_code.variables import variables
 
 
+def get_kwargs(include_orig=True):
+    return list(variables.keys()) + ['ctx', 'msg', 'print', 'client'] + ['orig'] if include_orig else []
+
+
 async def eval_message(code: str, message: Message, uses_orig=False) -> None:
     await message_design.edit_message(message, code, 'Running...')
 

app/run_code/parse_code.py

@@ -6,19 +6,52 @@ class _Result:
     uses_orig = False
 
 
-def parse_code(text: str):
+def _is_node_unknown_variable(node: ast.AST, locs: dict) -> bool:
+    """Check if AST node is a Name or Attribute not present in locals"""
+    if isinstance(node, ast.Attribute) and isinstance(node.value, ast.Name):
+        return node.value.id not in locs
+    return isinstance(node, ast.Name) and node.id not in locs
+
+
+def _is_node_suspicious_binop(node: ast.AST, locs: dict) -> bool:
+    """Check if AST node can be an operand of binary operation (ast.BinOp, ast.Compare, ast.BoolOp)
+    with operands which do not pass _is_node_unknown_variable check, or is such operation"""
+    if _is_node_unknown_variable(node, locs):
+        return True
+    if not isinstance(node, (ast.BoolOp, ast.BinOp, ast.Compare)):
+        return False
+    if isinstance(node, ast.Compare):
+        return _is_node_unknown_variable(node.left, locs) and all(_is_node_unknown_variable(x, locs)
+                                                                  for x in node.comparators)
+    return all(_is_node_suspicious_binop(operand, locs)
+               for operand in ((node.left, node.right) if isinstance(node, ast.BinOp) else node.values))
+
+
+def _ignore_node(node: ast.AST, locs: dict) -> bool:
+    """Check if AST node didn't seem to be meant to be code"""
+    return (
+            # Messages like "python", "123" or "example.com"
+            isinstance(node, ast.Constant) or _is_node_unknown_variable(node, locs)
+            # Messages like "-1", "+spam" and "not foo.bar"
+            or isinstance(node, ast.UnaryOp) and isinstance(node.operand, (ast.Constant, ast.Name, ast.Attribute))
+            # Messages like one-two, one is two, one >= two, one.b in two.c
+            or _is_node_suspicious_binop(node, locs)
+            # Messages like "yes, understood"
+            or isinstance(node, ast.Tuple) and all(_ignore_node(elt, locs) for elt in node.elts)
+    )
+
+
+def parse_code(text: str, locs: dict) -> _Result:
+    """Parse given text and decide should it be evaluated as Python code"""
     result = _Result()
 
     try:
         root = ast.parse(text, '', 'exec')
     except (SyntaxError, ValueError):
         return result
 
-    if len(root.body) == 1 and isinstance(root.body[0], ast.Expr):
-        if isinstance(root.body[0].value, (ast.Constant, ast.Name)):
-            return result
-        if isinstance(root.body[0].value, ast.UnaryOp) and isinstance(root.body[0].value.operand, ast.Constant):
-            return result
+    if all(isinstance(body_item, ast.Expr) and _ignore_node(body_item.value, locs) for body_item in root.body):
+        return result
 
     result.is_code = True
 

guide/docs/code_detection.md

@@ -11,11 +11,23 @@ It turns out that regular text messages aren't often identified as code. TGPy ig
 
 Although, optional disabling of auto-detection might be added in the future.
 
-## Simple expressions
+## What is ignored?
 
-Simple names and constants are ignored. If you want to get some variable value, use `return variable`.
+TL;DR: Some simple expressions, which could be email addresses, URLs or several comma- or hyphen-separated words
+(as described in [issue 4](https://github.com/tm-a-t/TGPy/issues/4))
+
+??? note "More details"
+    In this section, an **unknown** variable is one not present in `locals` — that is, which were not saved in previous messages and which are not built in TGPy (as `ctx`, `orig`, `msg` and `print` are)
+    Unknown variables' attributes are also considered unknown
+
+    **Ignored** expressions are expressions in the list below:
+
+    * Constants like `1` or `"abcd"` and unknown variables 
+    * Binary operations on unknown variables (recursively, i.e., `a - b -c` is also ignored in case `a`, `b`, `c` are unknown)
+    * Unary operations on constants or unknown variables
+    * Tuples of ignored expressions
+    * Multiple ignored expressions (i.e. separated by `;` or newline)****
 
-In future updates some other simple expressions will be ignored, too.
 
 ## Cancel evaluation