Added a test for generator expression with attribute on element and f…

…ixed the contract violation output

icontract/__init__.py

@@ -82,8 +82,8 @@ def __init__(self,
             got = list(inspect.signature(repr_args).parameters.keys())
 
             if got != self.condition_args:
-                raise ValueError("Unexpected argument(s) of repr_args. Expected {}, got {}".format(
-                    self.condition_args, got))
+                raise ValueError(
+                    "Unexpected argument(s) of repr_args. Expected {}, got {}".format(self.condition_args, got))
 
         self._a_repr = a_repr if a_repr is not None else aRepr
 

icontract/ast_graph.py

@@ -51,8 +51,8 @@ def visit(self, root: ast.AST) -> None:
                     else:
                         if isinstance(field[0], ast.AST):
                             for i, item in enumerate(field):
-                                self._edges.append("node_{} -> node_{} [label=<{}[{}]>];".format(
-                                    id(node), id(item), name, i))
+                                self._edges.append(
+                                    "node_{} -> node_{} [label=<{}[{}]>];".format(id(node), id(item), name, i))
                             stack.extend(field)
 
                         else:

icontract/recompute.py

@@ -99,8 +99,8 @@ def visit_NameConstant(self, node: ast.NameConstant) -> Any:
     def visit_Name(self, node: ast.Name) -> Any:
         """Load the variable by looking it up in the variable look-up and in the built-ins."""
         if not isinstance(node.ctx, ast.Load):
-            raise NotImplementedError("Can only compute a value of Load on a name {}, but got context: {}".format(
-                node.id, node.ctx))
+            raise NotImplementedError(
+                "Can only compute a value of Load on a name {}, but got context: {}".format(node.id, node.ctx))
 
         result = None  # type: Optional[Any]
 

icontract/represent.py

@@ -72,11 +72,12 @@ def visit_Name(self, node: ast.Name) -> None:
 
     def visit_Attribute(self, node: ast.Attribute) -> None:
         """Represent the attribute by dumping its source code."""
-        value = self._recomputed_values[node]
+        if node in self._recomputed_values:
+            value = self._recomputed_values[node]
 
-        if _representable(value=value):
-            text = self._atok.get_text(node)
-            self.reprs[text] = value
+            if _representable(value=value):
+                text = self._atok.get_text(node)
+                self.reprs[text] = value
 
         self.generic_visit(node=node)
 
@@ -216,9 +217,8 @@ def inspect_lambda_condition(condition: Callable[..., bool]) -> Optional[LambdaI
 
         assert lambda_node is not None, "Expected to find a keyword AST node with 'condition' arg, but found none"
     else:
-        raise AssertionError(
-            "Expected a call AST node of a decorator to have either args or keywords, but got: {}".format(
-                ast.dump(call_node)))
+        raise AssertionError("Expected a call AST node of a decorator to have either args or keywords, but got: {}".
+                             format(ast.dump(call_node)))
 
     return LambdaInspection(atok=atok, node=lambda_node)
 

tests/test_icontract.py

@@ -13,7 +13,7 @@
 import reprlib
 import time
 import unittest
-from typing import Optional, List, Callable, Any, Type  # pylint: disable=unused-import
+from typing import Optional, List, Callable, Any, Tuple, Type  # pylint: disable=unused-import
 
 import icontract
 

tests/test_represent.py

@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 # pylint: disable=missing-docstring,invalid-name,too-many-public-methods,no-self-use
-
+import pathlib
 import unittest
-from typing import Optional  # pylint: disable=unused-import
+from typing import Optional, List, Tuple  # pylint: disable=unused-import
 
 import icontract.represent
 
@@ -350,7 +350,22 @@ def func(x: int) -> int:
 
         self.assertIsNotNone(not_implemented_err)
 
-    def test_generator_expression(self):
+    def test_generator_expression_with_attr_on_element(self):
+        @icontract.post(lambda result: all(single_res[1].is_absolute() for single_res in result))
+        def some_func() -> List[Tuple[pathlib.Path, pathlib.Path]]:
+            return [(pathlib.Path("/home/file1"), pathlib.Path("home/file2"))]
+
+        icontract_violation_error = None  # type: Optional[icontract.ViolationError]
+        try:
+            some_func()
+        except icontract.ViolationError as err:
+            icontract_violation_error = err
+
+        self.assertIsNotNone(icontract_violation_error)
+        self.assertEqual('all(single_res[1].is_absolute() for single_res in result): all(single_res[1].is_absolute() '
+                         'for single_res in result) was False', str(icontract_violation_error))
+
+    def test_generator_expression_multiple_for(self):
         lst = [1, 2, 3]
         another_lst = [4, 5, 6]