Add workspace abstraction (#2982)

* Add workspace abstraction

* Remove old workspace implementation

* Extract path resolution to a helper function

* Add api key requirements to new tests

tests/test_workspace.py

@@ -0,0 +1,86 @@
+from pathlib import Path
+
+import pytest
+
+from autogpt.workspace import Workspace
+
+_WORKSPACE_ROOT = Path("home/users/monty/auto_gpt_workspace")
+
+_ACCESSIBLE_PATHS = [
+    Path("."),
+    Path("test_file.txt"),
+    Path("test_folder"),
+    Path("test_folder/test_file.txt"),
+    Path("test_folder/.."),
+    Path("test_folder/../test_file.txt"),
+    Path("test_folder/../test_folder"),
+    Path("test_folder/../test_folder/test_file.txt"),
+]
+
+_INACCESSIBLE_PATHS = [
+    # Takes us out of the workspace
+    Path(".."),
+    Path("../test_file.txt"),
+    Path("../not_auto_gpt_workspace"),
+    Path("../not_auto_gpt_workspace/test_file.txt"),
+    Path("test_folder/../.."),
+    Path("test_folder/../../test_file.txt"),
+    Path("test_folder/../../not_auto_gpt_workspace"),
+    Path("test_folder/../../not_auto_gpt_workspace/test_file.txt"),
+    # Contains null bytes
+    Path("\x00"),
+    Path("\x00test_file.txt"),
+    Path("test_folder/\x00"),
+    Path("test_folder/\x00test_file.txt"),
+    # Absolute paths
+    Path("/"),
+    Path("/test_file.txt"),
+    Path("/home"),
+]
+
+
+@pytest.fixture()
+def workspace_root(tmp_path):
+    return tmp_path / _WORKSPACE_ROOT
+
+
+@pytest.fixture(params=_ACCESSIBLE_PATHS)
+def accessible_path(request):
+    return request.param
+
+
+@pytest.fixture(params=_INACCESSIBLE_PATHS)
+def inaccessible_path(request):
+    return request.param
+
+
+def test_sanitize_path_accessible(accessible_path, workspace_root):
+    full_path = Workspace._sanitize_path(
+        accessible_path,
+        root=workspace_root,
+        restrict_to_root=True,
+    )
+    assert full_path.is_absolute()
+    assert full_path.is_relative_to(workspace_root)
+
+
+def test_sanitize_path_inaccessible(inaccessible_path, workspace_root):
+    with pytest.raises(ValueError):
+        Workspace._sanitize_path(
+            inaccessible_path,
+            root=workspace_root,
+            restrict_to_root=True,
+        )
+
+
+def test_get_path_accessible(accessible_path, workspace_root):
+    workspace = Workspace(workspace_root, True)
+    full_path = workspace.get_path(accessible_path)
+    assert full_path.is_absolute()
+    assert full_path.is_relative_to(workspace_root)
+
+
+def test_get_path_inaccessible(inaccessible_path, workspace_root):
+    workspace = Workspace(workspace_root, True)
+    with pytest.raises(ValueError):
+        workspace.get_path(inaccessible_path)