tests: check JSON feed validity (#239)

Using https://pypi.org/project/jsonfeed-util/ during tests.

Author: Guts

requirements/testing.txt

@@ -3,7 +3,8 @@
 # Testing
 # -------
 
-feedparser>=6.0,<6.1
+feedparser>=6.0.11,<6.1
+jsonfeed-util>=1.1.2,<2
 mkdocs-material[imaging]>=9
 pytest-cov>=4,<4.2
 validator-collection>=1.5,<1.6

tests/dev/dev_json_feed_validation.py

@@ -0,0 +1,39 @@
+import json
+from pathlib import Path
+
+import jsonfeed as jf
+import requests
+from jsonfeedvalidator import ErrorTree, format_errors, validate_feed
+
+# read
+
+# Requesting a valid JSON feed!
+r = requests.get("https://arxiv-feeds.appspot.com/json/test")
+# Parse from raw text...
+feed_from_text = jf.Feed.parse_string(r.text)
+# ...or parse JSON separately.
+r_json = r.json()
+feed_from_json = jf.Feed.parse(r_json)
+
+print(feed_from_text.title)
+
+# # write
+# me = jf.Author(name="Lukas Schwab", url="https://github.com/lukasschwab")
+# feed = jf.Feed("My Feed Title", authors=[me])
+# item = jf.Item("some_item_id")
+# feed.items.append(item)
+
+# print(feed.toJSON())
+
+# read from file
+path_json_feed = Path(__file__).parent.joinpath("json_feed_sample.json")
+
+with path_json_feed.open("r", encoding="UTF-8") as in_json:
+    feed_data = json.load(in_json)
+
+
+feed_from_file = jf.Feed.parse(feed_data)
+print(feed_from_file.title)
+
+errors = validate_feed(feed_from_file)
+format_errors(feed_from_file, ErrorTree(errors))