public static async Task HaveCollectionsChanged()

in src/Microsoft.Extensions.Configuration.AzureAppConfiguration/Extensions/ConfigurationClientExtensions.cs [67:109]
33 lines of code
8 McCabe index (conditional complexity)

        public static async Task<bool> HaveCollectionsChanged(this ConfigurationClient client, KeyValueSelector keyValueSelector, IEnumerable<MatchConditions> matchConditions, IConfigurationSettingPageIterator pageIterator, CancellationToken cancellationToken)
        {
            if (matchConditions == null)
            {
                throw new ArgumentNullException(nameof(matchConditions));
            }

            if (keyValueSelector == null)
            {
                throw new ArgumentNullException(nameof(keyValueSelector));
            }

            if (keyValueSelector.SnapshotName != null)
            {
                throw new ArgumentException("Cannot check snapshot for changes.", $"{nameof(keyValueSelector)}.{nameof(keyValueSelector.SnapshotName)}");
            }

            SettingSelector selector = new SettingSelector
            {
                KeyFilter = keyValueSelector.KeyFilter,
                LabelFilter = keyValueSelector.LabelFilter
            };

            AsyncPageable<ConfigurationSetting> pageable = client.GetConfigurationSettingsAsync(selector, cancellationToken);

            using IEnumerator<MatchConditions> existingMatchConditionsEnumerator = matchConditions.GetEnumerator();

            await foreach (Page<ConfigurationSetting> page in pageable.AsPages(pageIterator, matchConditions).ConfigureAwait(false))
            {
                using Response response = page.GetRawResponse();

                // Return true if the lists of etags are different
                if ((!existingMatchConditionsEnumerator.MoveNext() ||
                    !existingMatchConditionsEnumerator.Current.IfNoneMatch.Equals(response.Headers.ETag)) &&
                    response.Status == (int)HttpStatusCode.OK)
                {
                    return true;
                }
            }

            // Need to check if pages were deleted and no change was found within the new shorter list of match conditions
            return existingMatchConditionsEnumerator.MoveNext();
        }