Add check that skeleton is not already adopted

Author: GDYendell

src/dls_python3_skeleton/__main__.py

@@ -3,7 +3,7 @@
 from argparse import ArgumentParser
 from configparser import ConfigParser
 from pathlib import Path
-from subprocess import STDOUT, CalledProcessError, check_output
+from subprocess import STDOUT, CalledProcessError, call, check_output
 from tempfile import TemporaryDirectory
 from typing import List
 
@@ -27,6 +27,7 @@
         "https://github.com/dls-controls/versiongit",
     ),
 }
+SKELETON_ROOT_COMMIT = "ededf00035e6ccfac78946213009c1ecd7c110a9"
 
 
 def git(*args, cwd=None) -> str:
@@ -139,6 +140,25 @@ def validate_package(args) -> str:
     return package
 
 
+def verify_not_adopted(root: Path):
+    """Verify that module has not already adopted skeleton"""
+
+    # This call does not print anything - the return code is 0 if it is an ancestor
+    not_adopted = call(  # 0 -> adopted and 1 -> not adopted, so invert here
+        [
+            "git",
+            "-C",
+            f"{root}",
+            "merge-base",
+            "--is-ancestor",
+            SKELETON_ROOT_COMMIT,
+            "HEAD",
+        ]
+    )
+
+    assert not_adopted, f"Package {root} has already adopted skeleton"
+
+
 def new(args):
     path: Path = args.path
 
@@ -175,6 +195,8 @@ def existing(args):
     package = validate_package(args)
     file_path: Path = path / "setup.cfg"
     assert file_path.is_file(), "Expected a setup.cfg file in the directory."
+    verify_not_adopted(args.path)
+
     conf = ConfigParser()
     conf.read(path / "setup.cfg")
     assert "metadata" in conf, cfg_issue

tests/test_dls_python3_skeleton.py

@@ -125,3 +125,23 @@ def test_existing_module(tmp_path: Path):
     assert output.strip("\n") == f"{MERGE_BRANCH} deleted from existing repo"
     branches = __main__.list_branches(module)
     assert MERGE_BRANCH not in branches
+
+
+def test_existing_module_already_adopted(tmp_path: Path):
+    module = tmp_path / "scanspec"
+    __main__.git(
+        "clone",
+        "--branch",
+        "0.5.4",  # dls-python3-skeleton was adopted in this release
+        "https://github.com/dls-controls/scanspec",
+        str(module),
+    )
+    with pytest.raises(Exception) as excinfo:
+        check_output(
+            sys.executable,
+            "-m",
+            "dls_python3_skeleton",
+            "existing",
+            str(module),
+        )
+    assert "already adopted skeleton" in str(excinfo.value)