Properly negate with Interpreter, fixes #1636

jedi/inference/compiled/mixed.py

@@ -84,6 +84,9 @@ class MixedObject(ValueWrapper):
             return self.compiled_value.py__simple_getitem__(index)
         return self._wrapped_value.py__simple_getitem__(index)
 
+    def negate(self):
+        return self.compiled_value.negate()
+
     def _as_context(self):
         if self.parent_context is None:
             return MixedModuleContext(self)

test/test_api/test_interpreter.py

@@ -704,3 +704,11 @@ def test_variable_reuse():
     x = 1
     d, = jedi.Interpreter('y = x\ny', [locals()]).infer()
     assert d.name == 'int'
+
+
+def test_negate():
+    code = "x = -y"
+    x, = jedi.Interpreter(code, [{'y': 3}]).infer(1, 0)
+    assert x.name == 'int'
+    value, = x._name.infer()
+    assert value.get_safe_value() == -3