Fix issues with Python 3.6's f strings and underscores in numbers.

test/test_evaluate/test_literals.py

@@ -0,0 +1,37 @@
+import pytest
+
+import jedi
+from jedi._compatibility import py_version
+
+
+def _eval_literal(value):
+    def_, = jedi.Script(value).goto_definitions()
+    return def_._name._context
+
+
+@pytest.mark.skipif('sys.version_info[:2] < (3, 6)')
+def test_f_strings():
+    """
+    f literals are not really supported in Jedi. They just get ignored and an
+    empty string is returned.
+    """
+    context = _eval_literal('f"asdf"')
+    assert context.obj == ''
+    context = _eval_literal('f"{asdf}"')
+    assert context.obj == ''
+    context = _eval_literal('F"{asdf}"')
+    assert context.obj == ''
+    context = _eval_literal('rF"{asdf}"')
+    assert context.obj == ''
+
+
+def test_rb_strings():
+    context = _eval_literal('br"asdf"')
+    assert context.obj == b'asdf'
+    context = _eval_literal('rb"asdf"')
+    if py_version < 33:
+        # Before Python 3.3 there was a more strict definition in which order
+        # you could define literals.
+        assert context.obj == ''
+    else:
+        assert context.obj == b'asdf'