Add --from-branch cli arg

This will allow users to choose which skeleton branch they want to merge with their code.
If they do not supply this argument, then main will be used by default.

Author: MichaelStubbings

src/python3_pip_skeleton/__main__.py

@@ -52,6 +52,7 @@ def merge_skeleton(
     org: str,
     full_name: str,
     email: str,
+    from_branch: str,
     package,
 ):
     path = path.resolve()
@@ -82,7 +83,7 @@ def replace_text(text: str) -> str:
         # will do the wrong thing
         shutil.rmtree(git_tmp / "src", ignore_errors=True)
         # Merge in the skeleton commits
-        git_tmp("pull", "--rebase=false", SKELETON, "main")
+        git_tmp("pull", "--rebase=false", SKELETON, from_branch or "main")
         # Move things around
         if package != "python3_pip_skeleton":
             git_tmp("mv", "src/python3_pip_skeleton", f"src/{package}")
@@ -156,6 +157,7 @@ def new(args):
         org=args.org,
         full_name=args.full_name or git("config", "--get", "user.name").strip(),
         email=args.email or git("config", "--get", "user.email").strip(),
+        from_branch=args.from_branch,
         package=package,
     )
 
@@ -188,6 +190,7 @@ def existing(args):
         org=args.org,
         full_name=conf["metadata"]["author"],
         email=conf["metadata"]["author_email"],
+        from_branch=args.from_branch,
         package=package,
     )
 
@@ -225,6 +228,11 @@ def main(args=None):
     sub.add_argument(
         "--email", default=None, help="Email address, defaults to git config user.email"
     )
+    sub.add_argument(
+        "--from-branch",
+        default=None,
+        help="Merge from skeleton branch, defaults to main",
+    )
     # Add a command for adopting in existing repo
     sub = subparsers.add_parser("existing", help="Adopt skeleton in existing repo")
     sub.set_defaults(func=existing)
@@ -234,6 +242,11 @@ def main(args=None):
     sub.add_argument(
         "--package", default=None, help="Package name, defaults to directory name"
     )
+    sub.add_argument(
+        "--from-branch",
+        default=None,
+        help="Merge from skeleton branch, defaults to main",
+    )
     # Add a command for cleaning an existing repo of skeleton code
     sub = subparsers.add_parser(
         "clean", help="Clean up branch from failed skeleton merge"

tests/test_adopt.py

@@ -89,6 +89,42 @@ def test_new_module_existing_dir(tmp_path: Path):
     assert "to not exist, or be an empty dir" in str(excinfo.value)
 
 
+def test_new_module_merge_from_valid_branch(tmp_path: Path):
+    module = tmp_path / "my-module"
+    check_output(
+        sys.executable,
+        "-m",
+        "python3_pip_skeleton",
+        "new",
+        "--org=myorg",
+        "--package=my_module",
+        "--full-name=Firstname Lastname",
+        "[email protected]",
+        "--from-branch=main",
+        str(module),
+    )
+    assert check_output("git", "branch", cwd=module).strip() == "* main"
+
+
+def test_new_module_merge_from_invalid_branch(tmp_path: Path):
+    module = tmp_path / "my-module"
+
+    with pytest.raises(ValueError) as excinfo:
+        check_output(
+            sys.executable,
+            "-m",
+            "python3_pip_skeleton",
+            "new",
+            "--org=myorg",
+            "--package=my_module",
+            "--full-name=Firstname Lastname",
+            "[email protected]",
+            "--from-branch=fail",
+            str(module),
+        )
+    assert "couldn't find remote ref fail" in str(excinfo.value)
+
+
 def test_existing_module(tmp_path: Path):
     module = tmp_path / "scanspec"
     __main__.git(
@@ -169,3 +205,27 @@ def test_existing_module_already_adopted(tmp_path: Path):
             str(module),
         )
     assert "already adopted skeleton" in str(excinfo.value)
+
+
+def test_existing_module_merge_from_invalid_branch(tmp_path: Path):
+    module = tmp_path / "scanspec"
+    __main__.git(
+        "clone",
+        "--depth",
+        "1",
+        "--branch",
+        "0.5.3",
+        "https://github.com/dls-controls/scanspec",
+        str(module),
+    )
+    with pytest.raises(ValueError) as excinfo:
+        check_output(
+            sys.executable,
+            "-m",
+            "python3_pip_skeleton",
+            "existing",
+            "--org=epics-containers",
+            "--from-branch=fail",
+            str(module),
+        )
+    assert "couldn't find remote ref fail" in str(excinfo.value)