feat: update demo handling to create new feature branches when targeting template feature branches

Author: 56kyle

scripts/lint-from-demo.py

@@ -17,6 +17,7 @@
 import typer
 from retrocookie.core import retrocookie
 
+from util import DEMO
 from util import git
 from util import FolderOption
 from util import in_new_demo
@@ -40,23 +41,22 @@ def lint_from_demo(
     no_cache: Annotated[bool, typer.Option("--no-cache", "-n")] = False
 ) -> None:
     """Runs precommit in a generated project and matches the template to the results."""
-    develop_branch: str = os.getenv("COOKIECUTTER_ROBUST_PYTHON_DEVELOP_BRANCH", "develop")
     with in_new_demo(
         demos_cache_folder=demos_cache_folder,
         add_rust_extension=add_rust_extension,
         no_cache=no_cache
     ) as demo_path:
-        require_clean_and_up_to_date_repo()
-        git("checkout", develop_branch)
+        require_clean_and_up_to_date_repo(demo_path=demo_path)
+        git("checkout", DEMO.develop_branch)
         git("branch", "-D", "temp/lint-from-demo", ignore_error=True)
-        git("checkout", "-b", "temp/lint-from-demo", develop_branch)
+        git("checkout", "-b", "temp/lint-from-demo", DEMO.develop_branch)
         pre_commit.main.main(["run", "--all-files", "--show-diff-on-failure"])
 
         for path in IGNORED_FILES:
             git("checkout", "HEAD", "--", path)
         git("add", ".")
         git("commit", "-m", "meta: lint-from-demo", "--no-verify")
-    retrocookie(instance_path=demo_path, commits=[f"{develop_branch}..temp/lint-from-demo"])
+    retrocookie(instance_path=demo_path, commits=[f"{DEMO.develop_branch}..temp/lint-from-demo"])
 
 
 if __name__ == '__main__':

scripts/release-demo.py

@@ -40,7 +40,7 @@ def release_demo(
     demo_path: Path = demos_cache_folder / demo_name
 
     with work_in(demo_path):
-        require_clean_and_up_to_date_repo()
+        require_clean_and_up_to_date_repo(demo_path)
         git("checkout", DEMO.develop_branch)
         try:
             nox("setup-release", "--", "MINOR")

scripts/update-demo.py

@@ -10,12 +10,16 @@
 
 import sys
 from pathlib import Path
+from subprocess import CompletedProcess
 from typing import Annotated
+from typing import Optional
 
 import cruft
 import typer
 from cookiecutter.utils import work_in
 
+from scripts.util import TEMPLATE
+from util import DEMO
 from util import is_ancestor
 from util import get_current_branch
 from util import get_current_commit
@@ -46,9 +50,10 @@ def update_demo(
         current_branch: str = get_current_branch()
         template_commit: str = get_current_commit()
 
-        _validate_is_feature_branch(branch=current_branch)
-        _set_demo_to_clean_develop(demo_path=demo_path)
-        last_update_commit: str = _get_last_demo_develop_cruft_update(demo_path=demo_path)
+        _validate_template_main_not_checked_out(branch=current_branch)
+        require_clean_and_up_to_date_repo(demo_path=demo_path)
+        _checkout_demo_develop_or_existing_branch(demo_path=demo_path, branch=current_branch)
+        last_update_commit: str = get_last_cruft_update_commit(demo_path=demo_path)
 
         if not is_ancestor(last_update_commit, template_commit):
             raise ValueError(
@@ -83,23 +88,53 @@ def update_demo(
         sys.exit(1)
 
 
-def _set_demo_to_clean_develop(demo_path: Path) -> None:
-    """Checks out the demo development branch and validates it is up to date."""
+def _checkout_demo_develop_or_existing_branch(demo_path: Path, branch: str) -> None:
+    """Checkout either develop or an existing demo branch."""
     with work_in(demo_path):
-        require_clean_and_up_to_date_repo()
+        if __has_existing_local_demo_branch(demo_path=demo_path, branch=branch):
+            typer.secho(f"Local demo found, updating demo from base {branch}")
+            git("checkout", branch)
+            return
+
+        if __has_existing_remote_demo_branch(demo_path=demo_path, branch=branch):
+            remote_branch: str = f"{DEMO.remote}/{branch}"
+            typer.secho(f"Remote demo found, updating demo from base {remote_branch}")
+            git("checkout", "-b", branch, remote_branch)
+            return
+
         git("checkout", "develop")
 
 
-def _get_last_demo_develop_cruft_update(demo_path: Path) -> str:
-    """Gets the last cruft update commit for the demo project's develop branch."""
-    last_update_commit: str = get_last_cruft_update_commit(demo_path=demo_path)
-    return last_update_commit
+def __has_existing_local_demo_branch(demo_path: Path, branch: str) -> bool:
+    """Returns whether a local branch has been made for the given branch."""
+    with work_in(demo_path):
+        local_result: Optional[CompletedProcess] = git("branch", "--list", branch, text=True)
+        return local_result is not None and branch in local_result.stdout
+
+
+def __has_existing_remote_demo_branch(demo_path: Path, branch: str) -> bool:
+    """Returns whether a remote branch has been made for the given branch."""
+    with work_in(demo_path):
+        remote_result: Optional[CompletedProcess] = git("ls-remote", DEMO.remote, branch, text=True)
+        return remote_result is not None and branch in remote_result.stdout
+
+
+def _set_demo_to_clean_branch(demo_path: Path, branch: str) -> None:
+    """Checks out the demo branch and validates it is up to date."""
+    with work_in(demo_path):
+        git("checkout", "develop")
+
 
+def _validate_template_main_not_checked_out(branch: str) -> None:
+    """Validates that the cookiecutter isn't currently on main.
 
-def _validate_is_feature_branch(branch: str) -> None:
-    """Validates that the cookiecutter has a feature branch checked out."""
-    if not branch.startswith("feature/"):
-        raise ValueError(f"Received branch '{branch}' is not a feature branch.")
+    We allow direct develop commits (although avoid it usually), but never direct main. This may change later if the
+    template moves to a trunk based structure, but for now options are being kept open due to the possibility of a
+    package release handling demo creation one day.
+    """
+    main_like_names: list[str] = ["main", "master"]
+    if branch == TEMPLATE.main_branch or branch in main_like_names:
+        raise ValueError(f"Updating demos directly to main is not allowed currently.")
 
 
 if __name__ == '__main__':

scripts/util.py

@@ -127,11 +127,13 @@ def run_command(command: str, *args: str, ignore_error: bool = False) -> Optiona
 gh: partial[subprocess.CompletedProcess] = partial(run_command, "gh")
 
 
-def require_clean_and_up_to_date_repo() -> None:
+def require_clean_and_up_to_date_repo(demo_path: Path) -> None:
     """Checks if the repo is clean and up to date with any important branches."""
-    git("fetch")
-    git("status", "--porcelain")
-    validate_is_synced_ancestor(ancestor=DEMO.main_branch, descendent=DEMO.develop_branch)
+    with work_in(demo_path):
+        git("fetch")
+        git("status", "--porcelain")
+        validate_is_synced_ancestor(ancestor=DEMO.main_branch, descendent=DEMO.develop_branch)
+    typer.secho
 
 
 def validate_is_synced_ancestor(ancestor: str, descendent: str) -> None: