.gitea/preparse.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Reproduces the CI "Preparse .sage files" step locally, so `ruff check` sees
+# the same generated *.sage.py files that the pipeline lints. Run this before
+# `sage --python -m ruff check --no-respect-gitignore .` to catch issues that
+# only show up in the generated output (e.g. missing trailing newlines).
+#
+# The generated files are gitignored; clean them up afterwards with:
+#   git clean -x sage/ playground/
+
+set -e
+
+for f in $(find . -name "*.sage" -not -path "./playground/*"); do
+  sage --preparse "$f"
+  printf 'from sage.all import *  # noqa: F401,F403\n%s\n' "$(cat "${f}.py")" > "${f}.py"
+done

.gitea/workflows/ci.yml

@@ -24,12 +24,7 @@ jobs:
         # parse it, and prepends the `from sage.all import *` that `sage`
         # normally injects at runtime, so Sage's globals (ZZ, var, matrix, ...)
         # resolve instead of looking like undefined names.
-        run: |
-          set -e
-          for f in $(find . -name "*.sage" -not -path "./playground/*"); do
-            sage --preparse "$f"
-            printf 'from sage.all import *  # noqa: F401,F403\n%s\n' "$(cat "${f}.py")" > "${f}.py"
-          done
+        run: .gitea/preparse.sh
 
       - name: ruff check
         # --no-respect-gitignore: *.sage.py is gitignored (it's generated, see

pyproject.toml

@@ -23,7 +23,10 @@ ignore = [
 #   so trailing-whitespace warnings fire mechanically on almost every line
 #   with a number in it -- not something `ruff format` could fix anyway,
 #   since it wouldn't change the .sage source that generated it.
-"*.sage.py" = ["F403", "F405", "F821", "E741", "E402", "E702", "I001", "W291", "W293"]
+# - W292: whether the reconstructed file ends in a real trailing newline
+#   depends on how many blank lines the preparser appends, which varies by
+#   Sage version -- not something worth pinning tool versions over.
+"*.sage.py" = ["F403", "F405", "F821", "E741", "E402", "E702", "I001", "W291", "W293", "W292"]
 
 # tests/test_smoke.py does `from sage.all import *` and `load(...)` a .sage
 # file to get at its classes -- the same dynamic-namespace situation as