nixos-rebuild-ng: introduce models.BuildingAttr

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

@@ -9,7 +9,7 @@ from tempfile import TemporaryDirectory
 from typing import assert_never
 
 from . import nix
-from .models import Action, Flake, NRError, Profile
+from .models import Action, BuildAttr, Flake, NRError, Profile
 from .process import Remote, cleanup_ssh
 from .utils import info
 
@@ -170,6 +170,7 @@ def execute(argv: list[str]) -> None:
 
     profile = Profile.from_name(args.profile_name)
     target_host = Remote.from_arg(args.target_host, args.ask_sudo_password, tmpdir_path)
+    build_attr = BuildAttr.from_arg(args.attr, args.file)
     flake = Flake.from_arg(args.flake, target_host)
 
     if args.upgrade or args.upgrade_all:
@@ -204,8 +205,7 @@ def execute(argv: list[str]) -> None:
                 else:
                     path_to_config = nix.nixos_build(
                         "system",
-                        args.attr,
-                        args.file,
+                        build_attr,
                         no_out_link=True,
                         **build_flags,
                     )
@@ -244,8 +244,7 @@ def execute(argv: list[str]) -> None:
             else:
                 path_to_config = nix.nixos_build(
                     "system",
-                    args.attr,
-                    args.file,
+                    build_attr,
                     dry_run=dry_run,
                     **build_flags,
                 )
@@ -269,8 +268,7 @@ def execute(argv: list[str]) -> None:
             else:
                 path_to_config = nix.nixos_build(
                     attr,
-                    args.attr,
-                    args.file,
+                    build_attr,
                     **build_flags,
                 )
             vm_path = next(path_to_config.glob("bin/run-*-vm"), "./result/bin/run-*-vm")
@@ -307,12 +305,10 @@ def execute(argv: list[str]) -> None:
                 )
                 print(table)
         case Action.REPL:
-            # For now just redirect it to `nixos-rebuild` instead of
-            # duplicating the code
-            os.execv(
-                "@nixos_rebuild@",
-                argv,
-            )
+            if flake:
+                nix.repl_flake("toplevel", flake, **flake_build_flags)
+            else:
+                nix.repl("system", build_attr, **build_flags)
         case _:
             assert_never(action)
 

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

@@ -45,6 +45,18 @@ class Action(Enum):
         return [a.value for a in Action]
 
 
+@dataclass(frozen=True)
+class BuildAttr:
+    path: Path
+    attr: str | None
+
+    @classmethod
+    def from_arg(cls, attr: str | None, file: str | None) -> Self | None:
+        if not (attr or file):
+            return None
+        return cls(Path(file or "default.nix"), attr)
+
+
 @dataclass(frozen=True)
 class Flake:
     path: Path

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

@@ -6,6 +6,7 @@ from typing import Final
 
 from .models import (
     Action,
+    BuildAttr,
     Flake,
     Generation,
     GenerationJson,
@@ -235,24 +236,20 @@ def list_generations(profile: Profile) -> list[GenerationJson]:
 
 def nixos_build(
     attr: str,
-    pre_attr: str | None,
-    file: str | None,
+    build_attr: BuildAttr | None,
     **nix_flags: Args,
 ) -> Path:
     """Build NixOS attribute using classic Nix.
 
-    It will by default build  `<nixpkgs/nixos>` with `attr`, however it
-    optionally supports building from an external file and custom attributes
-    paths.
-
     Returns the built attribute as path.
     """
-    if pre_attr or file:
+    run_args: list[str | Path]
+    if build_attr:
         run_args = [
             "nix-build",
-            file or "default.nix",
+            build_attr.path,
             "--attr",
-            f"{'.'.join(x for x in [pre_attr, attr] if x)}",
+            f"{'.'.join(x for x in [build_attr.attr, attr] if x)}",
         ]
     else:
         run_args = ["nix-build", "<nixpkgs/nixos>", "--attr", attr]

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

@@ -9,6 +9,19 @@ import nixos_rebuild.models as m
 from .helpers import get_qualified_name
 
 
+def test_building_attr_from_arg() -> None:
+    assert m.BuildAttr.from_arg(None, None) is None
+    assert m.BuildAttr.from_arg("attr", None) == m.BuildAttr(
+        Path("default.nix"), "attr"
+    )
+    assert m.BuildAttr.from_arg("attr", "file.nix") == m.BuildAttr(
+        Path("file.nix"), "attr"
+    )
+    assert m.BuildAttr.from_arg(None, "file.nix") == m.BuildAttr(
+        Path("file.nix"), None
+    )
+
+
 def test_flake_parse() -> None:
     assert m.Flake.parse("/path/to/flake#attr") == m.Flake(
         Path("/path/to/flake"), "nixosConfigurations.attr"

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

@@ -229,27 +229,21 @@ def test_nixos_build_flake(mock_run: Any) -> None:
     return_value=CompletedProcess([], 0, stdout=" \n/path/to/file\n "),
 )
 def test_nixos_build(mock_run: Any, monkeypatch: Any) -> None:
-    assert n.nixos_build("attr", None, None, nix_flag="foo") == Path("/path/to/file")
+    assert n.nixos_build("attr", None, nix_flag="foo") == Path("/path/to/file")
     mock_run.assert_called_with(
         ["nix-build", "<nixpkgs/nixos>", "--attr", "attr", "--nix-flag", "foo"],
         stdout=PIPE,
     )
 
-    n.nixos_build("attr", "preAttr", "file")
+    n.nixos_build("attr", m.BuildAttr(Path("file"), "preAttr"))
     mock_run.assert_called_with(
-        ["nix-build", "file", "--attr", "preAttr.attr"],
+        ["nix-build", Path("file"), "--attr", "preAttr.attr"],
         stdout=PIPE,
     )
 
-    n.nixos_build("attr", None, "file", no_out_link=True)
+    n.nixos_build("attr", m.BuildAttr(Path("file"), None))
     mock_run.assert_called_with(
-        ["nix-build", "file", "--attr", "attr", "--no-out-link"],
-        stdout=PIPE,
-    )
-
-    n.nixos_build("attr", "preAttr", None, no_out_link=False, keep_going=True)
-    mock_run.assert_called_with(
-        ["nix-build", "default.nix", "--attr", "preAttr.attr", "--keep-going"],
+        ["nix-build", Path("file"), "--attr", "attr"],
         stdout=PIPE,
     )