Govern task context and advance execution pointer

tools/web/check-library-desktop.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+import hashlib
+import json
+import os
+import pathlib
+import sys
+import tempfile
+
+import bpy
+
+
+def library_report():
+    libraries = list(bpy.data.libraries)
+    if len(libraries) != 1:
+        raise RuntimeError(f"expected one library, found {len(libraries)}")
+    library = libraries[0]
+    return {
+        "id": "library:" + library.name,
+        "name": library.name,
+        "sourcePath": library.filepath,
+        "packed": library.packed_file is not None,
+        "readOnly": True,
+        "dependencyIds": [],
+    }
+
+
+def main() -> None:
+    arguments = sys.argv[sys.argv.index("--") + 1 :]
+    if len(arguments) != 2:
+        raise SystemExit("usage: blender -b --python check-library-desktop.py -- FIXTURE REPORT")
+    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
+    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=False)
+    before = library_report()
+    descriptor, temporary = tempfile.mkstemp(prefix="m16-library-reopen-", suffix=".blend", dir=fixture.parent)
+    os.close(descriptor)
+    try:
+        bpy.ops.wm.save_as_mainfile(filepath=temporary, check_existing=False, compress=True)
+        bpy.ops.wm.open_mainfile(filepath=temporary, load_ui=False)
+        after = library_report()
+    finally:
+        pathlib.Path(temporary).unlink(missing_ok=True)
+    if before != after:
+        raise RuntimeError(f"library save/reopen drift: {before} != {after}")
+    report = {
+        "schemaVersion": 1,
+        "task": "M16-GAP-00011",
+        "operation": "LIBRARY_DATABLOCK_DESKTOP",
+        "fixture": str(fixture),
+        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
+        "library": after,
+        "saveReopen": "EXACT",
+        "blenderVersion": bpy.app.version_string,
+    }
+    output.parent.mkdir(parents=True, exist_ok=True)
+    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+    print(f"library-desktop-ok id={after['id']} sourcePath={after['sourcePath']} saveReopen=exact")
+
+
+if __name__ == "__main__":
+    main()