Add an E2E test suite

e2e_tests/test_worktree_conversion.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+
+import tempfile
+
+from helpers import *
+
+
+def test_convert():
+    with TempGitRepository() as git_dir:
+        cmd = grm(["wt", "convert"], cwd=git_dir)
+        assert cmd.returncode == 0
+
+        files = os.listdir(git_dir)
+        assert len(files) == 1
+        assert files[0] == ".git-main-working-tree"
+
+        cmd = grm(["wt", "add", "test"], cwd=git_dir)
+        assert cmd.returncode == 0
+
+        files = os.listdir(git_dir)
+        assert len(files) == 2
+        assert set(files) == {".git-main-working-tree", "test"}
+
+
+def test_convert_already_worktree():
+    with TempGitRepositoryWorktree() as git_dir:
+        before = checksum_directory(git_dir)
+
+        cmd = grm(["wt", "convert"], cwd=git_dir)
+        assert cmd.returncode != 0
+
+        after = checksum_directory(git_dir)
+        assert before == after
+
+
+def test_convert_non_git():
+    with NonGitDir() as dir:
+        before = checksum_directory(dir)
+
+        cmd = grm(["wt", "convert"], cwd=dir)
+        assert cmd.returncode != 0
+
+        after = checksum_directory(dir)
+        assert before == after
+
+
+def test_convert_empty():
+    with EmptyDir() as dir:
+        before = checksum_directory(dir)
+
+        cmd = grm(["wt", "convert"], cwd=dir)
+        assert cmd.returncode != 0
+
+        after = checksum_directory(dir)
+        assert before == after