Implement single-file packages

Fixes #5

src/python/cram/__main__.py

@@ -2,28 +2,22 @@
 
 import logging
 import os
-from pathlib import Path
 import pickle
-from typing import List, Optional, Union
-import re
 import platform
-from pprint import pformat
+import re
 from collections import defaultdict
-
-from . import (
-    __author__,
-    __copyright__,
-    __license__,
-    __version__,
-)
-from .v0 import PackageV0, ProfileV0
-from .v1 import PackageV1, ProfileV1
+from pathlib import Path
+from pprint import pformat
+from typing import List, Optional, Union
 
 import click
 import toml
 from toposort import toposort_flatten
 from vfs import Vfs
 
+from . import __author__, __copyright__, __license__, __version__
+from .v0 import PackageV0, ProfileV0
+from .v1 import LightPackageV1, PackageV1, ProfileV1
 
 log = logging.getLogger(__name__)
 
@@ -114,7 +108,7 @@ def load(root: Path, name: str, clss):
 
 def load_package(root, name):
     log.debug(f"Attempting to load package {name} from {root}")
-    return load(root, name, [PackageV1, PackageV0])
+    return load(root, name, [LightPackageV1, PackageV1, PackageV0])
 
 
 def load_profile(root, name):

src/python/cram/common.py

@@ -1,14 +1,13 @@
 #!/usr/bin/env python3
 
 import os
+import sys
 from pathlib import Path
 from shlex import quote as sh_quote
-import sys
 from typing import List, Optional
 
 from vfs import Vfs
 
-
 # FIXME: This should be a config somewhere
 SHELL = "/bin/sh"
 

src/python/cram/v0.py

@@ -3,13 +3,13 @@
 An ill-considered pseudo-format.
 """
 
-from pathlib import Path
 import re
-
-from .common import Package, sh, stow
+from pathlib import Path
 
 from vfs import Vfs
 
+from .common import Package, sh, stow
+
 
 class PackageV0(Package):
     """The original package format from install.sh."""

src/python/cram/v1.py

@@ -9,11 +9,11 @@ from hashlib import sha256
 from pathlib import Path
 from typing import List, Optional, Union
 
-from .common import Package, sh, stow
-
 import toml
 from vfs import Vfs
 
+from .common import Package, sh, stow
+
 
 def tempf(name):
     root = Path("/tmp/stow")
@@ -94,11 +94,29 @@ class PackageV1(Package):
     def post_install(self, fs: Vfs, dest: Path):
         self.do_sh_or_script(self.config().get("package", {}).get("post_install"), fs, dest)
 
-
     def json(self):
         return self.config()
 
 
+class LightPackageV1(PackageV1):
+    """A package with no file content, defined in a single file."""
+
+    SPECIAL_FILES = []
+    _config = None
+
+    def config(self):
+        if not self._config:
+            with open(self.root, "r") as fp:
+                self._config = toml.load(fp)
+        return self._config
+
+    def test(self):
+        return self.root.exists() \
+            and self.root.is_file() \
+            and self.root.name.endswith(".toml") \
+            and self.config().get("cram", {}).get("version") == 1
+
+
 class ProfileV1(PackageV1):
     """Unline packages, profiles don't support recursive stow of contents."""
 

src/python/vfs/impl.py

@@ -6,7 +6,6 @@ import logging
 from shutil import rmtree
 from subprocess import run
 
-
 _log = logging.getLogger(__name__)
 
 

test/integration/packages.d/p8.toml

@@ -0,0 +1,5 @@
+[cram]
+version = 1
+
+[[package.install]]
+run = "echo 'ok'"

tools/autoflake/__main__.py

@@ -9,7 +9,6 @@ import sys
 
 from autoflake import main
 
-
 if __name__ == "__main__":
     sys.argv[0] = re.sub(r"(-script\.pyw|\.exe)?$", "", sys.argv[0])
     sys.exit(main())

tools/black/__main__.py

@@ -5,7 +5,6 @@ import sys
 
 from black import nullcontext, patched_main
 
-
 parser = argparse.ArgumentParser()
 parser.add_argument("--output-file", default=None)
 

tools/flake8/__main__.py

@@ -1,5 +1,4 @@
 from flake8.main import cli
 
-
 if __name__ == "__main__":
     cli.main()

tools/isort/__main__.py

@@ -9,7 +9,6 @@ import sys
 
 from isort.main import main
 
-
 if __name__ == "__main__":
     sys.argv[0] = re.sub(r"(-script\.pyw?|\.exe)?$", "", sys.argv[0])
     sys.exit(main())

tools/python/bzl_pytest_shim.py

@@ -4,7 +4,6 @@ import sys
 
 import pytest
 
-
 if __name__ == "__main__":
     cmdline = ["--ignore=external"] + sys.argv[1:]
     print(cmdline, file=sys.stderr)

tools/python/test_licenses.py

@@ -4,12 +4,8 @@ Validate 3rdparty library licenses as approved.
 
 import re
 
-from pkg_resources import (
-    DistInfoDistribution,
-    working_set,
-)
 import pytest
-
+from pkg_resources import DistInfoDistribution, working_set
 
 # Licenses approved as representing non-copyleft and not precluding commercial usage.
 # This is all easy, there's a good schema here.

tools/unify/__main__.py

@@ -7,6 +7,5 @@ Shim for executing isort.
 
 from unify import main
 
-
 if __name__ == "__main__":
     exit(main())