nixos-rebuild-ng: fix repl behaving differently on git flakes than bu… (NixOS#375493)

Author: thiagokokada

pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py

@@ -61,6 +61,25 @@ def from_arg(cls, attr: str | None, file: str | None) -> Self:
         return cls(Path(file or "default.nix"), attr)
 
 
+def discover_git(location: Path) -> str | None:
+    current = location.resolve()
+    previous = None
+
+    while current.is_dir() and current != previous:
+        dotgit = current / ".git"
+        if dotgit.is_dir():
+            return str(current)
+        elif dotgit.is_file():  # this is a worktree
+            with dotgit.open() as f:
+                dotgit_content = f.read().strip()
+                if dotgit_content.startswith("gitdir: "):
+                    return dotgit_content.split("gitdir: ")[1]
+        previous = current
+        current = current.parent
+
+    return None
+
+
 @dataclass(frozen=True)
 class Flake:
     path: Path | str
@@ -84,11 +103,15 @@ def parse(
         assert m is not None, f"got no matches for {flake_str}"
         attr = m.group("attr")
         nixos_attr = f"nixosConfigurations.{attr or hostname_fn() or 'default'}"
-        path = m.group("path")
-        if ":" in path:
-            return cls(path, nixos_attr)
+        path_str = m.group("path")
+        if ":" in path_str:
+            return cls(path_str, nixos_attr)
         else:
-            return cls(Path(path), nixos_attr)
+            path = Path(path_str)
+            git_repo = discover_git(path)
+            if git_repo is not None:
+                return cls(f"git+file://{git_repo}", nixos_attr)
+            return cls(path, nixos_attr)
 
     @classmethod
     def from_arg(cls, flake_arg: Any, target_host: Remote | None) -> Self | None:

pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_models.py

@@ -4,6 +4,8 @@
 from typing import Any
 from unittest.mock import patch
 
+from pytest import MonkeyPatch
+
 import nixos_rebuild.models as m
 
 from .helpers import get_qualified_name
@@ -30,7 +32,7 @@ def test_build_attr_to_attr() -> None:
     )
 
 
-def test_flake_parse() -> None:
+def test_flake_parse(tmpdir: Path, monkeypatch: MonkeyPatch) -> None:
     assert m.Flake.parse("/path/to/flake#attr") == m.Flake(
         Path("/path/to/flake"), "nixosConfigurations.attr"
     )
@@ -40,15 +42,31 @@ def test_flake_parse() -> None:
     assert m.Flake.parse("/path/to/flake", lambda: "hostname") == m.Flake(
         Path("/path/to/flake"), "nixosConfigurations.hostname"
     )
-    assert m.Flake.parse(".#attr") == m.Flake(Path("."), "nixosConfigurations.attr")
-    assert m.Flake.parse("#attr") == m.Flake(Path("."), "nixosConfigurations.attr")
-    assert m.Flake.parse(".") == m.Flake(Path("."), "nixosConfigurations.default")
+    # change directory to tmpdir
+    with monkeypatch.context() as patch_context:
+        patch_context.chdir(tmpdir)
+        assert m.Flake.parse(".#attr") == m.Flake(Path("."), "nixosConfigurations.attr")
+        assert m.Flake.parse("#attr") == m.Flake(Path("."), "nixosConfigurations.attr")
+        assert m.Flake.parse(".") == m.Flake(Path("."), "nixosConfigurations.default")
     assert m.Flake.parse("path:/to/flake#attr") == m.Flake(
         "path:/to/flake", "nixosConfigurations.attr"
     )
     assert m.Flake.parse("github:user/repo/branch") == m.Flake(
         "github:user/repo/branch", "nixosConfigurations.default"
     )
+    git_root = tmpdir / "git_root"
+    git_root.mkdir()
+    (git_root / ".git").mkdir()
+    assert m.Flake.parse(str(git_root)) == m.Flake(
+        f"git+file://{git_root}", "nixosConfigurations.default"
+    )
+
+    work_tree = tmpdir / "work_tree"
+    work_tree.mkdir()
+    (work_tree / ".git").write_text("gitdir: /path/to/git", "utf-8")
+    assert m.Flake.parse(str(work_tree)) == m.Flake(
+        "git+file:///path/to/git", "nixosConfigurations.default"
+    )
 
 
 def test_flake_to_attr() -> None:
@@ -61,7 +79,7 @@ def test_flake_to_attr() -> None:
 
 
 @patch(get_qualified_name(platform.node), autospec=True)
-def test_flake_from_arg(mock_node: Any) -> None:
+def test_flake_from_arg(mock_node: Any, monkeypatch: MonkeyPatch, tmpdir: Path) -> None:
     mock_node.return_value = "hostname"
 
     # Flake string
@@ -73,9 +91,11 @@ def test_flake_from_arg(mock_node: Any) -> None:
     assert m.Flake.from_arg(False, None) is None
 
     # True
-    assert m.Flake.from_arg(True, None) == m.Flake(
-        Path("."), "nixosConfigurations.hostname"
-    )
+    with monkeypatch.context() as patch_context:
+        patch_context.chdir(tmpdir)
+        assert m.Flake.from_arg(True, None) == m.Flake(
+            Path("."), "nixosConfigurations.hostname"
+        )
 
     # None when we do not have /etc/nixos/flake.nix
     with patch(

pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py

@@ -6,6 +6,7 @@
 from unittest.mock import ANY, call, patch
 
 import pytest
+from pytest import MonkeyPatch
 
 import nixos_rebuild.models as m
 import nixos_rebuild.nix as n
@@ -51,7 +52,8 @@ def test_build(mock_run: Any, monkeypatch: Any) -> None:
     autospec=True,
     return_value=CompletedProcess([], 0, stdout=" \n/path/to/file\n "),
 )
-def test_build_flake(mock_run: Any) -> None:
+def test_build_flake(mock_run: Any, monkeypatch: MonkeyPatch, tmpdir: Path) -> None:
+    monkeypatch.chdir(tmpdir)
     flake = m.Flake.parse(".#hostname")
 
     assert n.build_flake(
@@ -165,7 +167,10 @@ def run_wrapper_side_effect(
     autospec=True,
     return_value=CompletedProcess([], 0, stdout=" \n/path/to/file\n "),
 )
-def test_build_remote_flake(mock_run: Any, monkeypatch: Any) -> None:
+def test_build_remote_flake(
+    mock_run: Any, monkeypatch: MonkeyPatch, tmpdir: Path
+) -> None:
+    monkeypatch.chdir(tmpdir)
     flake = m.Flake.parse(".#hostname")
     build_host = m.Remote("user@host", [], None)
     monkeypatch.setenv("NIX_SSHOPTS", "--ssh opts")
@@ -287,7 +292,7 @@ def test_copy_closure(monkeypatch: Any) -> None:
 @patch(get_qualified_name(n.run_wrapper, n), autospec=True)
 def test_edit(mock_run: Any, monkeypatch: Any, tmpdir: Any) -> None:
     # Flake
-    flake = m.Flake.parse(".#attr")
+    flake = m.Flake.parse(f"{tmpdir}#attr")
     n.edit(flake, {"commit_lock_file": True})
     mock_run.assert_called_with(
         [
@@ -297,7 +302,7 @@ def test_edit(mock_run: Any, monkeypatch: Any, tmpdir: Any) -> None:
             "edit",
             "--commit-lock-file",
             "--",
-            ".#nixosConfigurations.attr",
+            f"{tmpdir}#nixosConfigurations.attr",
         ],
         check=False,
     )