Add a script to fetch schemas from mozilla-central

requirements.txt

@@ -2,3 +2,4 @@ jsonschema==3.2.0
 PyYAML==5.4
 yamllint==1.21.0
 pyjexl==0.3.0
+requests>=2.27.1,<2.28.0

scripts/fetch-schemas.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from pathlib import Path
+
+import requests
+
+URL_BASE = "https://hg.mozilla.org/mozilla-central/raw-file/tip/"
+
+SCHEMAS = {
+    # The combined FxMS Mega schema
+    "MessagingExperiment.schema.json": (
+        "browser/components/newtab/content-src/asrouter/schemas/"
+        "MessagingExperiment.schema.json"
+    ),
+    # The Nimbus recipe schema
+    "NimbusExperiment.schema.json": (
+        "toolkit/components/nimbus/schemas/NimbusExperiment.schema.json"
+    ),
+    # Non-message schemas
+    "SpecialMessageActionSchemas.json": (
+        "toolkit/components/messaging-system/schemas/"
+        "SpecialMessageActionSchemas/SpecialMessageActionSchemas.json"
+    ),
+    "message-groups.schema.json": (
+        "browser/components/newtab/content-src/asrouter/schemas/"
+        "message-group.schema.json"
+    ),
+}
+
+
+def main():
+    session = requests.session()
+
+    for schema, fragment in SCHEMAS.items():
+        path = Path("schema") / schema
+        url = URL_BASE + fragment
+
+        print(f"Fetching {schema} ...")
+
+        with path.open("w") as f, session.get(url) as req:
+            f.write(req.text)
+
+
+if __name__ == "__main__":
+    main()

scripts/validate.py

@@ -4,7 +4,6 @@ import json
 import sys
 
 import jsonschema
-
 from jsonschema.exceptions import best_match, ValidationError
 from pyjexl.jexl import JEXL