chore: support dart3, fix queryRaw for InfluxDB Cloud

CHANGELOG.md

@@ -1,5 +1,11 @@
 ## 2.9.0 [unreleased]
 
+### Bug Fixes
+1. [#124](https://github.com/influxdata/influxdb-client-dart/pull/124): `queryRaw` for InfluxDB Cloud
+
+### Others
+1. [#124](https://github.com/influxdata/influxdb-client-dart/pull/124): Add compatibility with Dart 3
+
 ## 2.8.0 [2022-12-01]
 
 ### Others

lib/client/flux_transformer.dart

@@ -187,7 +187,7 @@ class FluxTransformer implements StreamTransformer<List, FluxRecord> {
     }
 
     var duplicates = table.columns.map((item) => item.label).toList();
-    duplicates.toSet().forEach((item) => {duplicates.remove(item)});
+    duplicates.toSet().forEach((item) => duplicates.remove(item));
 
     if (duplicates.isNotEmpty) {
       logPrint('The response contains columns with duplicated names:'

lib/client/query_service.dart

@@ -44,13 +44,8 @@ class QueryService extends DefaultService {
     query.params = params ?? query.params;
     query.dialect = dialect ?? query.dialect;
 
-    var uri = _buildUri(influxDB.url!, '/api/v2/query', {'org': influxDB.org});
-    var body = jsonEncode(query);
-    Map<String, String> headers = {};
-    _updateParamsForAuth(headers);
-    var response = await _invoke(uri, 'POST',
-        headers: headers, body: body, maxRedirects: influxDB.maxRedirects);
-    return (response as Response).body;
+    var response = await _send('/api/v2/query', {'org': influxDB.org}, query);
+    return (response as StreamedResponse).stream.bytesToString();
   }
 
   /// Streams the result of [fluxQuery] using [Dialect].