Test renames better and change some small things about the refactoring API

test/test_api/test_refactoring.py

@@ -0,0 +1,57 @@
+import os
+from textwrap import dedent
+
+import pytest
+
+import jedi
+
+
+@pytest.fixture()
+def dir_with_content(tmpdir):
+    with open(os.path.join(tmpdir.strpath, 'modx.py'), 'w') as f:
+        f.write('import modx\nfoo\n')  # self reference
+    return tmpdir.strpath
+
+
+def test_rename_mod(Script, dir_with_content):
+    script = Script(
+        'import modx; modx\n',
+        path=os.path.join(dir_with_content, 'some_script.py'),
+        project=jedi.Project(dir_with_content),
+    )
+    refactoring = script.rename(line=1, new_name='modr')
+    refactoring.apply()
+
+    p1 = os.path.join(dir_with_content, 'modx.py')
+    p2 = os.path.join(dir_with_content, 'modr.py')
+    expected_code = 'import modr\nfoo\n'
+    assert not os.path.exists(p1)
+    with open(p2) as f:
+        assert f.read() == expected_code
+
+    assert refactoring.get_renames() == [(p1, p2)]
+
+    assert refactoring.get_changed_files()[p1].get_new_code() == expected_code
+
+    assert refactoring.get_diff() == dedent('''\
+        rename from {dir}/modx.py
+        rename to {dir}/modr.py
+        --- {dir}/modx.py
+        +++ {dir}/modr.py
+        @@ -1,3 +1,3 @@
+        -import modx
+        +import modr
+         foo
+        --- {dir}/some_script.py
+        +++ {dir}/some_script.py
+        @@ -1,2 +1,2 @@
+        -import modx; modx
+        +import modr; modr
+        ''').format(dir=dir_with_content)
+
+
+def test_rename_none_path(Script):
+    refactoring = Script('foo', path=None).rename(new_name='bar')
+    with pytest.raises(jedi.RefactoringError, match='on a Script with path=None'):
+        refactoring.apply()
+    assert refactoring