API - Invert changes_only flag for include_equal parameter, add test, fixes changesOnly option for history diff API call (#3976)

changedetectionio/api/Watch.py

@@ -338,7 +338,7 @@ class WatchHistoryDiff(Resource):
             word_diff = True
 
         # Get boolean diff preferences with defaults from DIFF_PREFERENCES_CONFIG
-        changes_only = strtobool(request.args.get('changesOnly', 'true'))
+        changes_only = strtobool(request.args.get('changesOnly', 'false'))
         ignore_whitespace = strtobool(request.args.get('ignoreWhitespace', 'false'))
         include_removed = strtobool(request.args.get('removed', 'true'))
         include_added = strtobool(request.args.get('added', 'true'))
@@ -349,7 +349,7 @@ class WatchHistoryDiff(Resource):
             previous_version_file_contents=from_version_file_contents,
             newest_version_file_contents=to_version_file_contents,
             ignore_junk=ignore_whitespace,
-            include_equal=changes_only,
+            include_equal=not changes_only,
             include_removed=include_removed,
             include_added=include_added,
             include_replaced=include_replaced,
@@ -567,4 +567,4 @@ class CreateWatch(Resource):
 
                 return {'status': f'OK, queueing {len(watches_to_queue)} watches in background'}, 202
 
-        return list, 200
+        return list, 200

changedetectionio/tests/test_api.py

@@ -170,6 +170,14 @@ def test_api_simple(client, live_server, measure_memory_usage, datastore_path):
         headers={'x-api-key': api_key},
     )
     assert b'(changed) Which is across' in res.data
+    assert b'Some text thats the same' in res.data
+
+    # Fetch the difference between two versions (default text format)
+    res = client.get(
+        url_for("watchhistorydiff", uuid=watch_uuid, from_timestamp='previous', to_timestamp='latest')+"?changesOnly=true",
+        headers={'x-api-key': api_key},
+    )
+    assert b'Some text thats the same' not in res.data
 
     # Test htmlcolor format
     res = client.get(