feat: make it possible to build subprojects from python packages

beet/toolchain/helpers.py

@@ -3,29 +3,56 @@
     "sandbox",
     "run_beet",
     "JinjaExtension",
+    "SubprojectError",
 ]
 
 
 from contextlib import ExitStack, contextmanager
+from functools import wraps
 from pathlib import Path
 from tempfile import TemporaryDirectory
-from typing import Iterator, Optional, Union
+from typing import Iterator, Optional, Union, overload
 
 from jinja2 import Environment
 from jinja2.ext import Extension
 
-from beet.core.utils import FileSystemPath, JsonDict
+from beet.core.utils import FileSystemPath, JsonDict, import_from_string
+from beet.toolchain.pipeline import FormattedPipelineException
 
 from .config import ProjectConfig, config_error_handler
-from .context import Context, Plugin, PluginSpec, ProjectCache
+from .context import Context, Pipeline, Plugin, PluginSpec, ProjectCache
 from .project import Project, ProjectBuilder
 from .template import TemplateManager
 from .worker import WorkerPool
 
 
+class SubprojectError(FormattedPipelineException):
+    """Raised when a subproject fails to build."""
+
+    def __init__(self, message: str):
+        super().__init__(message)
+        self.message = message
+        self.format_cause = True
+
+
+@overload
 def subproject(config: Union[ProjectConfig, JsonDict, FileSystemPath]) -> Plugin:
+    ...
+
+
+@overload
+def subproject(config: Optional[str] = None, *, package: str) -> Plugin:
+    ...
+
+
+def subproject(
+    config: Optional[Union[ProjectConfig, JsonDict, FileSystemPath]] = None,
+    *,
+    package: Optional[str] = None,
+) -> Plugin:
     """Return a plugin that runs a subproject."""
 
+    @wraps(subproject)
     def plugin(ctx: Context):
         project = Project(
             resolved_cache=ctx.cache,
@@ -38,7 +65,31 @@ def plugin(ctx: Context):
             with config_error_handler("<subproject>"):
                 project.resolved_config = ProjectConfig(**config).resolve(ctx.directory)
         else:
-            path = Path(config)
+            if package:
+                whitelist = ctx.inject(Pipeline).whitelist
+
+                try:
+                    imported_package = import_from_string(package, whitelist=whitelist)
+                except Exception as exc:
+                    msg = (
+                        f'Couldn\'t import package "{package}" for building subproject.'
+                    )
+                    raise SubprojectError(msg) from exc
+
+                if filename := getattr(imported_package, "__file__", None):
+                    path = Path(filename).parent
+                else:
+                    msg = f'Missing "__file__" attribute on package "{package}" for building subproject.'
+                    raise SubprojectError(msg)
+
+                if config:
+                    path /= config
+
+            elif config:
+                path = Path(config)
+
+            else:
+                raise SubprojectError("No config provided for building subproject.")
 
             if path.is_dir():
                 project.config_directory = path

examples/load_subproject_package/beet.yml

@@ -0,0 +1 @@
+require: [demo]

examples/load_subproject_package/demo/__init__.py

@@ -0,0 +1,5 @@
+from beet import Context, subproject
+
+
+def beet_default(ctx: Context):
+    ctx.require(subproject(package="demo"))

examples/load_subproject_package/demo/beet.yml

@@ -0,0 +1,2 @@
+data_pack:
+  load: [src]

examples/load_subproject_package/demo/src/data/demo/functions/foo.mcfunction

@@ -0,0 +1 @@
+say hello

tests/snapshots/examples__build_load_subproject_package__0.data_pack/data/demo/functions/foo.mcfunction

@@ -0,0 +1 @@
+say hello

tests/snapshots/examples__build_load_subproject_package__0.data_pack/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 9,
+    "description": ""
+  }
+}

tests/snapshots/examples__build_load_subproject_package__1.resource_pack/pack.mcmeta

@@ -0,0 +1,6 @@
+{
+  "pack": {
+    "pack_format": 8,
+    "description": ""
+  }
+}