Add tests

tests/helpers.py

@@ -1,3 +1,15 @@
+from main.options import AlignmentMode, Options, WriteBackMode
+
+OPTIONS = [
+    Options(
+        write_back=WriteBackMode.CHECK,
+        step_keyword_alignment=alignment_mode,
+        fast=False,
+    )
+    for alignment_mode in AlignmentMode
+]
+
+
 def get_content(file_name):
     with open(f"tests/data/valid/{file_name}.feature") as f:
         return f.read()

tests/test_core.py

@@ -3,8 +3,8 @@
 import pytest
 
 from main import core
-from main.errors import EquivalentError, InternalError
-from tests.helpers import dump_to_stderr, get_content
+from main.errors import EquivalentError, InternalError, NothingChanged, StableError
+from tests.helpers import OPTIONS, dump_to_stderr, get_content
 
 
 def test_assert_equivalent():
@@ -30,3 +30,38 @@ def test_assert_equivalent_invalid_dst(invalid_contents):
 
     with pytest.raises(InternalError):
         core.assert_equivalent(login_content, invalid_content)
+
+
+@pytest.mark.parametrize("options", OPTIONS)
+def test_assert_stable(valid_contents, options):
+    for content in valid_contents:
+        formatted_content = core.format_file_contents(content, options=options)
+
+        core.assert_stable(content, formatted_content, options=options)
+
+
+@pytest.mark.parametrize("options", OPTIONS)
+@patch("main.core.dump_to_file", dump_to_stderr)
+def test_assert_stable_fail(options):
+    src = dst = get_content("full")
+
+    with pytest.raises(StableError):
+        core.assert_stable(src, dst, options=options)
+
+
+@pytest.mark.parametrize("options", OPTIONS)
+def test_format_file_contents(valid_contents, options):
+    for src in valid_contents:
+        core.format_file_contents(src, options=options)
+
+
+@pytest.mark.parametrize("options", OPTIONS)
+def test_format_file_contents_no_change(options):
+    with pytest.raises(NothingChanged):
+        core.format_file_contents("", options=options)
+
+    content = get_content("full")
+    formatted_content = core.format_file_contents(content, options=options)
+
+    with pytest.raises(NothingChanged):
+        core.format_file_contents(formatted_content, options=options)