feat: add tool exposing editable files (#95)

Author: mtth

src/git_draft/drafter.py

@@ -479,6 +479,10 @@ def on_rename_file(
             dst_path=str(dst_path),
         )
 
+    def on_expose_files(self) -> None:
+        self._progress.report("Exposed files.")
+        self._record(None, "expose_files")
+
     def _record(self, reason: str | None, tool: str, **kwargs) -> None:
         op = _Operation(
             tool=tool, details=kwargs, reason=reason, start=datetime.now()

src/git_draft/git.py

@@ -79,17 +79,16 @@ def fullname(self) -> str:
 class Repo:
     """Git repository"""
 
-    def __init__(self, working_dir: Path, uuid: uuid.UUID) -> None:
+    def __init__(self, working_dir: Path) -> None:
         self.working_dir = working_dir
-        self.uuid = uuid
 
     @classmethod
     def enclosing(cls, path: Path) -> Self:
         """Returns the repo enclosing the given path"""
         call = GitCall.sync("rev-parse", "--show-toplevel", working_dir=path)
         working_dir = Path(call.stdout)
-        uuid = _ensure_repo_uuid(working_dir)
-        return cls(working_dir, uuid)
+        _ensure_repo_uuid(working_dir)
+        return cls(working_dir)
 
     def git(
         self,
@@ -107,6 +106,12 @@ def git(
             working_dir=self.working_dir,
         )
 
+    @property
+    def uuid(self) -> uuid.UUID:
+        value = _get_config_value(_ConfigKey.REPO_UUID, self.working_dir)
+        assert value
+        return uuid.UUID(value)
+
     def active_branch(self) -> str | None:
         return self.git("branch", "--show-current").stdout or None
 
@@ -125,10 +130,9 @@ def _get_config_value(key: _ConfigKey, working_dir: Path) -> str | None:
     return None if call.code else call.stdout
 
 
-def _ensure_repo_uuid(working_dir: Path) -> uuid.UUID:
-    value = _get_config_value(_ConfigKey.REPO_UUID, working_dir)
-    if value:
-        return uuid.UUID(value)
+def _ensure_repo_uuid(working_dir: Path) -> None:
+    if _get_config_value(_ConfigKey.REPO_UUID, working_dir):
+        return
     repo_uuid = uuid.uuid4()
     GitCall.sync(
         "config",
@@ -138,7 +142,6 @@ def _ensure_repo_uuid(working_dir: Path) -> uuid.UUID:
         working_dir=working_dir,
     )
     _logger.debug("Set repo UUID. [uuid=%s]", repo_uuid)
-    return repo_uuid
 
 
 def null_delimited(arg: str) -> Iterator[str]:

src/git_draft/toolbox.py

@@ -3,10 +3,11 @@
 from __future__ import annotations
 
 import collections
-from collections.abc import Callable, Sequence
+from collections.abc import Callable, Iterator, Sequence
+import contextlib
 import dataclasses
 import logging
-from pathlib import PurePosixPath
+from pathlib import Path, PurePosixPath
 import tempfile
 from typing import Protocol, Self, override
 
@@ -20,8 +21,8 @@
 class Toolbox:
     """File-system intermediary
 
-    Note that the toolbox is not thread-safe. Concurrent operations should be
-    serialized by the caller.
+    Note that toolbox implementations may not be thread-safe. Concurrent
+    operations should be serialized by the caller.
     """
 
     # TODO: Something similar to https://aider.chat/docs/repomap.html,
@@ -31,6 +32,13 @@ class Toolbox:
     # TODO: Support a diff-based edit method.
     # https://gist.github.com/noporpoise/16e731849eb1231e86d78f9dfeca3abc
 
+    # TODO: Add user feedback tool here. This will make it possible to request
+    # feedback more than once during a bot action, which leads to a better
+    # experience when used interactively.
+
+    # TODO: Remove all reason arguments. They are not currently used, and there
+    # is no obvious use-case at the moment.
+
     def __init__(self, visitors: Sequence[ToolVisitor] | None = None) -> None:
         self._visitors = visitors or []
 
@@ -78,9 +86,22 @@ def rename_file(
         dst_path: PurePosixPath,
         reason: str | None = None,
     ) -> None:
+        """Rename a single file"""
         self._dispatch(lambda v: v.on_rename_file(src_path, dst_path, reason))
         self._rename(src_path, dst_path)
 
+    def expose_files(
+        self,
+    ) -> contextlib.AbstractContextManager[Path]:  # pragma: no cover
+        """Creates a temporary folder with editable copies of all files
+
+        All updates are synced back afterwards. Other operations should not be
+        performed concurrently as they may be stale or lost.
+        """
+        self._dispatch(lambda v: v.on_expose_files())
+        # TODO: Expose updated files to hook?
+        return self._expose()
+
     def _list(self) -> Sequence[PurePosixPath]:  # pragma: no cover
         raise NotImplementedError()
 
@@ -103,6 +124,11 @@ def _rename(
         self._write(dst_path, contents)
         self._delete(src_path)
 
+    def _expose(
+        self,
+    ) -> contextlib.AbstractContextManager[Path]:  # pragma: no cover
+        raise NotImplementedError()
+
 
 class ToolVisitor(Protocol):
     """Tool usage hook"""
@@ -130,6 +156,8 @@ def on_rename_file(
         reason: str | None,
     ) -> None: ...  # pragma: no cover
 
+    def on_expose_files(self) -> None: ...  # pragma: no cover
+
 
 class NoopToolbox(Toolbox):
     """No-op read-only toolbox"""
@@ -150,6 +178,10 @@ def _write(self, _path: PurePosixPath, _contents: str) -> None:
     def _delete(self, _path: PurePosixPath) -> None:
         raise RuntimeError()
 
+    @override
+    def _expose(self) -> contextlib.AbstractContextManager[Path]:
+        raise RuntimeError()
+
 
 class RepoToolbox(Toolbox):
     """Git-repo backed toolbox implementation
@@ -177,22 +209,30 @@ def __init__(
     def for_working_dir(cls, repo: Repo) -> tuple[Self, bool]:
         index_tree_sha = repo.git("write-tree").stdout
         toolbox = cls(repo, index_tree_sha)
-
-        # Apply any changes from the working directory.
-        deleted = set[SHA]()
-        for path in null_delimited(repo.git("ls-files", "-dz").stdout):
-            deleted.add(path)
-            toolbox._delete(PurePosixPath(path))
-        for path in null_delimited(
-            repo.git("ls-files", "-moz", "--exclude-standard").stdout
-        ):
-            if path in deleted:
-                continue  # Deleted files also show up as modified
-            toolbox._write_from_disk(PurePosixPath(path), path)
-
+        toolbox._sync_updates()  # Apply any changes from the working directory
         head_tree_sha = repo.git("rev-parse", "HEAD^{tree}").stdout
         return toolbox, toolbox.tree_sha() != head_tree_sha
 
+    def _sync_updates(self, *, worktree_path: Path | None = None) -> None:
+        repo = self._repo
+        if worktree_path:
+            repo = Repo(worktree_path)
+
+        def ls_files(*args: str) -> Iterator[str]:
+            return null_delimited(repo.git("ls-files", *args).stdout)
+
+        deleted = set[str]()
+        for path_str in ls_files("-dz"):
+            deleted.add(path_str)
+            self._delete(PurePosixPath(path_str))
+        for path_str in ls_files("-moz", "--exclude-standard"):
+            if path_str in deleted:
+                continue  # Deleted files also show up as modified
+            self._write_from_disk(
+                PurePosixPath(path_str),
+                worktree_path / path_str if worktree_path else Path(path_str),
+            )
+
     def with_visitors(self, visitors: Sequence[ToolVisitor]) -> Self:
         return self.__class__(self._repo, self.tree_sha(), visitors)
 
@@ -224,17 +264,35 @@ def _write(self, path: PurePosixPath, contents: str) -> None:
         with tempfile.NamedTemporaryFile(delete_on_close=False) as temp:
             temp.write(contents.encode("utf8"))
             temp.close()
-            self._write_from_disk(path, temp.name)
+            self._write_from_disk(path, Path(temp.name))
+
+    @override
+    @contextlib.contextmanager
+    def _expose(self) -> Iterator[Path]:
+        tree_sha = self.tree_sha()
+        commit_sha = self._repo.git(
+            "commit-tree", "-m", "draft! worktree", tree_sha
+        ).stdout
+        with tempfile.TemporaryDirectory() as path_str:
+            try:
+                self._repo.git(
+                    "worktree", "add", "--detach", path_str, commit_sha
+                )
+                path = Path(path_str)
+                yield path
+                self._sync_updates(worktree_path=path)
+            finally:
+                self._repo.git("worktree", "remove", "-f", path_str)
 
     def _write_from_disk(
-        self, path: PurePosixPath, contents_path: str
+        self, path: PurePosixPath, contents_path: Path
     ) -> None:
         blob_sha = self._repo.git(
             "hash-object",
             "-w",
             "--path",
             str(path),
-            contents_path,
+            str(contents_path),
         ).stdout
         self._tree_updates.append(_WriteBlob(path, blob_sha))
 

tests/git_draft/toolbox_test.py

@@ -67,3 +67,28 @@ def test_for_working_dir_dirty(self) -> None:
         assert toolbox.read_file(PPP("f1")) == "aa"
         assert toolbox.read_file(PPP("f2")) is None
         assert toolbox.read_file(PPP("f3")) == "c"
+
+    def test_expose_files(self) -> None:
+        self._fs.write("f1", "a")
+        self._fs.write("f2", "b")
+        self._fs.flush()
+        toolbox = sut.RepoToolbox(self._repo, "HEAD")
+        toolbox.delete_file(PPP("f1"))
+        toolbox.write_file(PPP("f3"), "c")
+
+        with toolbox.expose_files() as path:
+            assert {".git", "f2", "f3"} == set(c.name for c in path.iterdir())
+            with open(path / "f2", "w") as w:
+                w.write("bb")
+            with open(path / "f4", "w") as w:
+                w.write("d")
+            (path / "f3").unlink()
+
+            # Before sync, toolbox does not have changes.
+            assert toolbox.read_file(PPP("f2")) == "b"
+            assert toolbox.read_file(PPP("f3")) == "c"
+
+        # After sync, toolbox has changes propagated.
+        assert toolbox.read_file(PPP("f2")) == "bb"
+        assert toolbox.read_file(PPP("f3")) is None
+        assert toolbox.read_file(PPP("f4")) == "d"