Fix some pyre errors in test

Some of these crept in before we had type-checking on node
constructors or decorators. So, lets fix these cases and get rid of a
few incorrect constructions in tests!

libcst/nodes/tests/test_assert.py

@@ -94,7 +94,7 @@ class AssertParsingTest(CSTNodeTest):
             {
                 "node": cst.Assert(cst.Name("True")),
                 "code": "assert True",
-                # pyre-ignore[16]
+                # pyre-fixme[16]: `BaseSuite` has no attribute `__getitem__`.
                 "parser": (lambda code: parse_statement(code).body[0]),
                 "expected_position": None,
             },

libcst/nodes/tests/test_atom.py

@@ -694,17 +694,13 @@ class AtomTest(CSTNodeTest):
             },
             {
                 "get_node": (
-                    # pyre-fixme[6]: Expected `Sequence[BaseFormattedStringContent]` for
-                    #  1st param but got `str`.
-                    lambda: cst.FormattedString("f''", lpar=(cst.LeftParen(),))
+                    lambda: cst.FormattedString(parts=(), lpar=(cst.LeftParen(),))
                 ),
                 "expected_re": "left paren without right paren",
             },
             {
                 "get_node": (
-                    # pyre-fixme[6]: Expected `Sequence[BaseFormattedStringContent]` for
-                    #  1st param but got `str`.
-                    lambda: cst.FormattedString("f''", rpar=(cst.RightParen(),))
+                    lambda: cst.FormattedString(parts=(), rpar=(cst.RightParen(),))
                 ),
                 "expected_re": "right paren without left paren",
             },

libcst/nodes/tests/test_binary_op.py

@@ -154,9 +154,7 @@ class BinaryOperationTest(CSTNodeTest):
                 "get_node": (
                     lambda: cst.BinaryOperation(
                         cst.Name("foo"),
-                        # pyre-fixme[6]: Expected `BaseBinaryOp` for 2nd param but got
-                        #  `Plus`.
-                        cst.Plus(),
+                        cst.Add(),
                         cst.Name("bar"),
                         lpar=(cst.LeftParen(),),
                     )
@@ -167,9 +165,7 @@ class BinaryOperationTest(CSTNodeTest):
                 "get_node": (
                     lambda: cst.BinaryOperation(
                         cst.Name("foo"),
-                        # pyre-fixme[6]: Expected `BaseBinaryOp` for 2nd param but got
-                        #  `Plus`.
-                        cst.Plus(),
+                        cst.Add(),
                         cst.Name("bar"),
                         rpar=(cst.RightParen(),),
                     )

libcst/nodes/tests/test_call.py

@@ -466,10 +466,8 @@ class CallTest(CSTNodeTest):
             (
                 lambda: cst.Call(
                     func=cst.Name("foo"),
-                    # pyre-fixme[6]: Expected `Union[typing_extensions.Literal[''],
-                    #  typing_extensions.Literal['*'],
-                    #  typing_extensions.Literal['**']]` for 1st param but got
-                    #  `typing_extensions.Literal['***']`.
+                    # pyre-ignore: Ignore type on 'star' since we're testing behavior
+                    # when somebody isn't using a type checker.
                     args=(cst.Arg(star="***", value=cst.SimpleString("'baz'")),),
                 ),
                 r"Must specify either '', '\*' or '\*\*' for star",

libcst/nodes/tests/test_cst_node.py

@@ -41,6 +41,8 @@ class _TestVisitor(CSTTransformer):
         self, original_node: _CSTNodeT, updated_node: _CSTNodeT
     ) -> Union[_CSTNodeT, RemovalSentinel]:
         self.test.assertTrue(original_node.deep_equals(updated_node))
+        # Don't allow type checkers to accidentally refine our return type.
+        return_node = updated_node
         if isinstance(updated_node, cst.Pass):
             self.assert_counter(3)
         elif isinstance(updated_node, cst.Newline):
@@ -49,9 +51,7 @@ class _TestVisitor(CSTTransformer):
             self.assert_counter(6)
         elif isinstance(updated_node, cst.Module):
             self.assert_counter(7)
-        # pyre: Expected `Union[RemovalSentinel, Variable[_CSTNodeT (bound to
-        # pyre-ignore[7]: cst._base.CSTNode)]]` but got `cst._statement.Pass`.
-        return updated_node
+        return return_node
 
 
 class CSTNodeTest(UnitTest):

libcst/nodes/tests/test_import.py

@@ -483,9 +483,9 @@ class ImportFromCreateTest(CSTNodeTest):
     @data_provider(
         (
             (
-                # pyre-fixme[6]: Expected `Union[Sequence[ImportAlias], ImportStar]`
-                #  for 2nd param but got `Tuple[Name]`.
-                lambda: cst.ImportFrom(module=None, names=(cst.Name("bar"),)),
+                lambda: cst.ImportFrom(
+                    module=None, names=(cst.ImportAlias(cst.Name("bar")),)
+                ),
                 "Must have a module specified",
             ),
             (