Move Glance keep rules to floret-kit, check R8 keeps reflective constructors in CI (#75)

scripts/check_r8_keeps.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""Fail when R8 keeps one of our classes by name but strips its no-arg constructor.
+
+A keep rule that names a class but no members keeps the class and lets R8 drop
+the constructor nothing calls directly. Anything that then instantiates it by
+reflection (Room, Glance's ActionCallback, WorkManager) fails at runtime only,
+in release builds only (#1, #75). R8 reports both halves: seeds.txt lists what
+keep rules pinned, usage.txt what it removed.
+
+    scripts/check_r8_keeps.py [mapping dir]   default: fullReleaseTest's
+"""
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+DEFAULT_DIR = ROOT / "app/build/outputs/mapping/fullReleaseTest"
+PACKAGES = ("de.jeanlucmakiola.",)
+
+
+def kept_classes(seeds: Path) -> set[str]:
+    return {
+        line.strip()
+        for line in seeds.read_text().splitlines()
+        if line.startswith(PACKAGES) and ":" not in line
+    }
+
+
+def classes_without_default_ctor(usage: Path) -> set[str]:
+    stripped, current = set(), None
+    for line in usage.read_text().splitlines():
+        if not line.startswith(" "):
+            current = line.rstrip(":") if line.endswith(":") else None
+        elif current and line.strip().endswith(" <init>()"):
+            stripped.add(current)
+    return stripped
+
+
+def main() -> int:
+    mapping = Path(sys.argv[1]) if len(sys.argv) > 1 else DEFAULT_DIR
+    seeds, usage = mapping / "seeds.txt", mapping / "usage.txt"
+    if not seeds.exists() or not usage.exists():
+        print(f"ERROR: no seeds.txt/usage.txt in {mapping}; build a minified variant first.", file=sys.stderr)
+        return 1
+    broken = sorted(kept_classes(seeds) & classes_without_default_ctor(usage))
+    for name in broken:
+        print(f"ERROR: {name} is kept by a rule but R8 removed its no-arg constructor.", file=sys.stderr)
+    if broken:
+        print("Keep the constructor too: -keep class ... { <init>(); }", file=sys.stderr)
+        return 1
+    print(f"OK: every kept class under {', '.join(PACKAGES)} still has its no-arg constructor.")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())