fixed del for nonlocal scopes; added test cases

Author: craigbarratt

custom_components/pyscript/eval.py

@@ -154,14 +154,14 @@ class EvalLocalVar:
     def __init__(self, name, **kwargs):
         """Initialize value of local symbol."""
         self.name = name
-        self.valid = False
+        self.defined = False
         if "value" in kwargs:
             self.value = kwargs["value"]
-            self.valid = True
+            self.defined = True
 
     def get(self):
         """Get value of local symbol."""
-        if not self.valid:
+        if not self.defined:
             raise NameError(f"name '{self.name}' is not defined")
         return self.value
 
@@ -172,15 +172,19 @@ def get_name(self):
     def set(self, value):
         """Set value of local symbol."""
         self.value = value
-        self.valid = True
+        self.defined = True
 
-    def defined(self):
-        """Return whether value is valid."""
-        return self.valid
+    def is_defined(self):
+        """Return whether value is defined."""
+        return self.defined
+
+    def set_undefined(self):
+        """Set local symbol to undefined."""
+        self.defined = False
 
     def __getattr__(self, attr):
         """Get attribute of local variable."""
-        if not self.valid:
+        if not self.defined:
             raise NameError(f"name '{self.name}' is not defined")
         return getattr(self.value, attr)
 
@@ -614,7 +618,7 @@ async def call(self, ast_ctx, args=None, kwargs=None):
         for name, value in self.local_sym_table.items():
             if name in sym_table:
                 sym_table[name] = EvalLocalVar(name, value=sym_table[name])
-            elif value.defined():
+            elif value.is_defined():
                 sym_table[name] = value
             else:
                 sym_table[name] = EvalLocalVar(name)
@@ -1145,9 +1149,15 @@ async def ast_delete(self, arg):
                     if arg1.id in self.global_sym_table:
                         del self.global_sym_table[arg1.id]
                 elif arg1.id in self.sym_table:
-                    del self.sym_table[arg1.id]
+                    if isinstance(self.sym_table[arg1.id], EvalLocalVar):
+                        if self.sym_table[arg1.id].is_defined():
+                            self.sym_table[arg1.id].set_undefined()
+                        else:
+                            raise NameError(f"name '{arg1.id}' is not defined")
+                    else:
+                        del self.sym_table[arg1.id]
                 else:
-                    raise NameError(f"name '{arg1.id}' is not defined in del")
+                    raise NameError(f"name '{arg1.id}' is not defined")
             else:
                 raise NotImplementedError(f"unknown target type {arg1} in del")
 
@@ -1662,6 +1672,10 @@ async def get_names_set(self, arg, names, nonlocal_names=None, global_names=None
                 local_names.add(arg.name)
                 names.add(arg.name)
                 return
+            elif cls_name == "Delete":
+                for arg1 in arg.targets:
+                    if isinstance(arg1, ast.Name):
+                        local_names.add(arg1.id)
         for child in ast.iter_child_nodes(arg):
             await self.get_names_set(
                 child,

tests/test_unit_eval.py

@@ -784,6 +784,38 @@ def f1(x):
 """,
         [3, 12, 16, 42],
     ],
+    [
+        """
+def func():
+    def f1():
+        nonlocal i
+        del i
+        i = 20
+        return i + 1
+
+    def f2():
+        return 2 * i
+
+    i = 10
+    return f1, f2
+
+f1, f2 = func()
+[f2(), f1(), f2()]
+""",
+        [20, 21, 40],
+    ],
+    [
+        """
+def func():
+    def func2():
+        z = x + 2
+        return z
+    x = 1
+    return func2()
+func()
+""",
+        3,
+    ],
 ]
 
 
@@ -836,7 +868,7 @@ async def test_eval(hass):
         "import math; math.sinXYZ",
         "Exception in test line 1 column 13: module 'math' has no attribute 'sinXYZ'",
     ],
-    ["del xx", "Exception in test line 1 column 0: name 'xx' is not defined in del"],
+    ["del xx", "Exception in test line 1 column 0: name 'xx' is not defined"],
     ["return", "Exception in test line 1 column 0: return statement outside function"],
     ["break", "Exception in test line 1 column 0: break statement outside loop"],
     ["continue", "Exception in test line 1 column 0: continue statement outside loop"],
@@ -912,6 +944,32 @@ def func():
 """,
         "Exception in test line 4 column 10: 'bad_key'",
     ],
+    [
+        """
+def func():
+    def func2():
+        nonlocal x
+        del x
+        del x
+    x = 1
+    func2()
+func()
+""",
+        "Exception in func2(), test line 6 column 8: name 'x' is not defined",
+    ],
+    [
+        """
+def func():
+    def func2():
+        z = x + 2
+        return z
+        del x
+    x = 1
+    return func2()
+func()
+""",
+        "Exception in func2(), test line 4 column 12: name 'x' is not defined",
+    ],
 ]