Skip arg count checks for dynamic functions. (#1433)

Author: gvanrossum

mypy/checkexpr.py

@@ -132,11 +132,7 @@ def visit_call_expr(self, e: CallExpr) -> Type:
             # It's really a special form that only looks like a call.
             return self.accept(e.analyzed, self.chk.type_context[-1])
         self.try_infer_partial_type(e)
-        self.accept(e.callee)
-        # Access callee type directly, since accept may return the Any type
-        # even if the type is known (in a dynamically typed function). This
-        # way we get a more precise callee in dynamically typed functions.
-        callee_type = self.chk.type_map[e.callee]
+        callee_type = self.accept(e.callee)
         if (self.chk.disallow_untyped_calls and
                 self.chk.typing_mode_full() and
                 isinstance(callee_type, CallableType)

mypy/test/data/check-dynamic-typing.test

@@ -655,3 +655,25 @@ class A(B):
         x()
 [out]
 main: note: In class "A":
+
+
+-- Don't complain about too few/many arguments in dynamic functions
+-- ----------------------------------------------------------------
+
+[case testTooManyArgsInDynamic]
+def f() -> None: pass
+def g():
+    f(1) # Silent
+[out]
+
+[case testTooFewArgsInDynamic]
+def f(a: int) -> None: pass
+def g():
+    f() # Silent
+[out]
+
+[case testJustRightInDynamic]
+def f(a: int) -> None: pass
+def g():
+    f('') # Silent
+[out]

mypy/test/data/typexport-basic.test

@@ -510,7 +510,7 @@ def f():
 def g(a: object) -> object: pass
 o = None # type: object
 [out]
-CallExpr(3) : builtins.object
+CallExpr(3) : Any
 NameExpr(3) : def (a: builtins.object) -> builtins.object
 NameExpr(3) : builtins.object
 
@@ -549,8 +549,8 @@ def f():
   A()
 class A(Generic[T]): pass
 [out]
-CallExpr(4) : A[Any]
-NameExpr(4) : def () -> A[Any]
+CallExpr(4) : Any
+NameExpr(4) : def [T] () -> A[T`-1]
 
 [case testGenericCallInDynamicallyTypedFunction2]
 from typing import TypeVar, Generic
@@ -560,8 +560,8 @@ def f():
 class A(Generic[T]):
     def __init__(self, x: T) -> None: pass
 [out]
-CallExpr(4) : A[Any]
-NameExpr(4) : def (x: Any) -> A[Any]
+CallExpr(4) : Any
+NameExpr(4) : def [T] (x: T`-1) -> A[T`-1]
 NameExpr(4) : def () -> Any
 
 [case testGenericCallInDynamicallyTypedFunction3]
@@ -572,7 +572,7 @@ def f():
 def g(x: t) -> t: pass
 [out]
 CallExpr(4) : Any
-NameExpr(4) : def (x: Any) -> Any
+NameExpr(4) : def [t] (x: t`-1) -> t`-1
 
 
 -- Generic types and type inference