test: unit tests for get_package and get_partitions methods

debcraft/application.py

@@ -17,6 +17,8 @@
 """Main Debcraft Application."""
 
 import craft_application
+import craft_parts
+from typing_extensions import override
 
 from debcraft import models
 
@@ -29,3 +31,8 @@
 
 class Application(craft_application.Application):
     """Debcraft application definition."""
+
+    @override
+    def _enable_craft_parts_features(self) -> None:
+        """Enable partitions for packages."""
+        craft_parts.Features(enable_partitions=True)

debcraft/control.py

@@ -0,0 +1,54 @@
+#  This file is part of debcraft.
+#
+#  Copyright 2025 Canonical Ltd.
+#
+#  This program is free software: you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License version 3, as
+#  published by the Free Software Foundation.
+#
+#  This program is distributed in the hope that it will be useful, but WITHOUT
+#  ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+#  SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.
+#  See the GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License along
+#  with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Debian control file encoder."""
+
+from typing import TextIO
+
+from debcraft import models
+
+
+class Encoder:
+    """Encoder for Debian control file format."""
+
+    def __init__(self, f: TextIO) -> None:
+        self._file = f
+
+    def encode(self, model: models.DebianControl) -> None:
+        """Encode the model."""
+        for name, field in model.__class__.model_fields.items():
+            value = getattr(model, name)
+            if value is None:
+                continue
+
+            key = field.alias or name
+
+            match value:
+                case None:
+                    continue
+                case str() if "\n" in value:
+                    lines = value.splitlines()
+                    self._file.write(f"{key}: {lines[0]}\n")
+                    for line in lines[1:]:
+                        if line.strip() == "":
+                            self._file.write(" .\n")
+                        else:
+                            self._file.write(f" {line}\n")
+                case list():
+                    line = ", ".join(map(str, value))  # pyright: ignore[reportUnknownVariableType,reportUnknownArgumentType]
+                    self._file.write(f"{key}: {line}\n")
+                case _:
+                    self._file.write(f"{key}: {value}\n")

debcraft/errors.py

@@ -0,0 +1,38 @@
+# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
+#
+# Copyright 2025 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Debcraft error definitions."""
+
+from craft_cli import CraftError
+
+
+class DebcraftError(CraftError):
+    """Failure in a Debcraft operation."""
+
+
+class FeatureNotImplemented(DebcraftError):
+    """Attempt to use an unimplemented feature."""
+
+    def __init__(self, msg: str) -> None:
+        super().__init__(f"Command or feature not implemented: {msg}")
+
+
+class PartsLifecycleError(DebcraftError):
+    """Error during parts processing."""
+
+
+class ProjectValidationError(DebcraftError):
+    """Error validating debcraft.yaml."""

debcraft/models/__init__.py

@@ -18,6 +18,8 @@
 
 from debcraft.models.metadata import Metadata
 from debcraft.models.project import Project
+from debcraft.models.package import Package
+from debcraft.models.control import DebianControl
 
 
-__all__ = ["Project", "Metadata"]
+__all__ = ["Project", "Package", "DebianControl", "Metadata"]

debcraft/models/control.py

@@ -0,0 +1,50 @@
+#  This file is part of debcraft.
+#
+#  Copyright 2025 Canonical Ltd.
+#
+#  This program is free software: you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License version 3, as
+#  published by the Free Software Foundation.
+#
+#  This program is distributed in the hope that it will be useful, but WITHOUT
+#  ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+#  SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.
+#  See the GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License along
+#  with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Debian control file model for Debcraft."""
+
+from craft_application import models
+from pydantic import ConfigDict
+
+
+def _field_alias(field_name: str) -> str:
+    parts = field_name.replace("_", "-").split("-")
+    capitalized_parts = [p.capitalize() for p in parts]
+    return "-".join(capitalized_parts)
+
+
+class DebianControl(models.CraftBaseModel):
+    """Debian control file definition."""
+
+    model_config = ConfigDict(alias_generator=_field_alias, populate_by_name=True)
+
+    package: str
+    source: str
+    version: str
+    architecture: str | list[str]
+    maintainer: str
+    installed_size: int
+    depends: list[str] | None = None
+    recommends: list[str] | None = None
+    conflicts: list[str] | None = None
+    breaks: list[str] | None = None
+    replaces: list[str] | None = None
+    provides: list[str] | None = None
+    section: str
+    priority: str
+    description: str
+    original_maintainer: str | None = None
+    uploaders: list[str] | None = None

debcraft/models/package.py

@@ -15,7 +15,7 @@
 #  with this program.  If not, see <http://www.gnu.org/licenses/>.
 """Model for defining deb binary packages."""
 
-from typing import Literal
+from typing import Literal, cast
 
 import pydantic
 from craft_application import models
@@ -31,8 +31,11 @@ class Package(models.CraftBaseModel):
     See: https://www.debian.org/doc/debian-policy/ch-controlfields.html
     """
 
-    architectures: Literal["any", "all"] | list[DebianArchitecture]
-    description: str | None = None  # Only none for the only pkg
+    architectures: Literal["any", "all"] | list[DebianArchitecture] | None = None
+    summary: str | None = None  # defaults to the project summary
+    description: str | None = None  # defaults to the project description
+
+    version: str | None = None  # defaults to the project version
 
     # These need validating: https://github.com/canonical/debcraft/issues/42
     # https://www.debian.org/doc/debian-policy/ch-relationships.html#s-binarydeps
@@ -50,3 +53,13 @@ class Package(models.CraftBaseModel):
 
     Use of this key indicates something incomplete in debcraft.
     """
+
+    def get_architecture(self) -> str | list[str] | None:
+        """Get the formatted package architecture."""
+        if self.architectures in ("all", "any"):
+            return cast(str, self.architectures)
+
+        if self.architectures:
+            return [str(x) for x in self.architectures]
+
+        return None

debcraft/models/project.py

@@ -24,6 +24,7 @@
 from craft_application import models
 from typing_extensions import Self
 
+from debcraft import errors
 from debcraft.models.package import Package
 
 DEBIAN_PACKAGE_NAME_REGEX = r"^[a-z0-9][a-z0-9.+-]+$"
@@ -97,3 +98,30 @@ def _validate_adopt_info_part_exists(self) -> Self:
         if self.adopt_info and self.adopt_info not in self.parts:
             raise ValueError("'adopt-info' field must refer to the name of a part.")
         return self
+
+    def get_package(self, name: str) -> Package:
+        """Obtain the package definition for the given package name."""
+        if not self.packages:
+            raise errors.DebcraftError("no packages defined")
+
+        package = self.packages.get(name)
+        if not package:
+            raise errors.DebcraftError(f"package {name} is not defined")
+
+        return package
+
+
+class PackagesProject(models.CraftBaseModel, extra="ignore"):
+    """Project definition containing only package data."""
+
+    packages: dict[DebianPackageName, Package] | None = None
+
+    def get_partitions(self) -> list[str] | None:
+        """Get a list of partitions based on the project's packages.
+
+        :returns: A list of packages formatted as ['default', 'package/<name>', ...]
+        """
+        if not self.packages:
+            return ["default"]
+
+        return ["default", *[f"package/{name}" for name in self.packages]]

debcraft/services/__init__.py

@@ -24,6 +24,9 @@ def register_services() -> None:
     """Register debcraft services to the service factory."""
     ServiceFactory.register("package", "Package", module="debcraft.services.package")
     ServiceFactory.register("project", "Project", module="debcraft.services.project")
+    ServiceFactory.register(
+        "lifecycle", "Lifecycle", module="debcraft.services.lifecycle"
+    )
 
 
 __all__ = ["BuildPlan", "ServiceFactory"]

debcraft/services/lifecycle.py

@@ -0,0 +1,72 @@
+#  This file is part of debcraft.
+#
+#  Copyright 2025 Canonical Ltd.
+#
+#  This program is free software: you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License version 3, as
+#  published by the Free Software Foundation.
+#
+#  This program is distributed in the hope that it will be useful, but WITHOUT
+#  ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+#  SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.
+#  See the GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License along
+#  with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""Debcraft Lifecycle Service."""
+
+from pathlib import Path
+
+from craft_application import LifecycleService
+from craft_parts import ProjectInfo
+
+from debcraft import errors
+
+
+class Lifecycle(LifecycleService):
+    """Debcraft specialization of the Lifecycle Service."""
+
+    def get_prime_dir(self, package: str | None = None) -> Path:
+        """Get the prime directory path for the default prime dir or a package.
+
+        :param package: Name of the package to get the prime directory for.
+
+        :returns: The default prime directory or a package's prime directory.
+
+        :raises DebcraftError: If the package does not exist.
+        """
+        try:
+            return self.prime_dirs[package]
+        except KeyError as err:
+            raise errors.DebcraftError(
+                f"Could not get prime directory for package {package!r} "
+                "because it does not exist."
+            ) from err
+
+    @property
+    def prime_dirs(self) -> dict[str | None, Path]:
+        """Return a mapping of package names to prime directories.
+
+        'None' maps to the default prime directory.
+        """
+        return _get_prime_dirs_from_project(self._lcm.project_info)
+
+
+def _get_prime_dirs_from_project(project_info: ProjectInfo) -> dict[str | None, Path]:
+    """Get a mapping of package names to prime directories from a ProjectInfo.
+
+    'None' maps to the default prime directory.
+
+    :param project_info: The ProjectInfo to get the prime directory mapping from.
+    """
+    partition_prime_dirs = project_info.prime_dirs
+    package_prime_dirs: dict[str | None, Path] = {None: project_info.prime_dir}
+
+    # strip 'component/' prefix so that the package name is the key
+    for partition, prime_dir in partition_prime_dirs.items():
+        if partition and partition.startswith("package/"):
+            package = partition.split("/", 1)[1]
+            package_prime_dirs[package] = prime_dir
+
+    return package_prime_dirs