fix: use default org and bucket

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## 4.2.0 [unreleased]
 
+### Bug Fixes
+1. [#313](https://github.com/influxdata/influxdb-client-csharp/pull/313): Using default `org` and `bucket` in `WriteApiAsync`
+
 ## 4.1.0 [2022-04-19]
 
 ### Features

Client.Test/WriteApiAsyncTest.cs

@@ -239,6 +239,31 @@ await writeApi.WriteRecordAsync(
                 ae.Message);
         }
 
+        [Test]
+        public async Task UseDefaultOrganizationAndBucket()
+        {
+            MockServer
+                .Given(Request.Create().WithPath("/api/v2/write").UsingPost())
+                .RespondWith(CreateResponse("{}"));
+
+            _influxDbClient.Dispose();
+
+            var options = InfluxDBClientOptions.Builder
+                .CreateNew()
+                .Url(MockServerUrl)
+                .AuthenticateToken("token")
+                .Bucket("my-bucket")
+                .Org("my-org")
+                .Build();
+
+            _influxDbClient = InfluxDBClientFactory.Create(options);
+
+            var writeApi = _influxDbClient.GetWriteApiAsync();
+            await writeApi.WriteRecordsAsyncWithIRestResponse(new[] { "mem,location=a level=1.0 1" });
+            await writeApi.WritePointsAsyncWithIRestResponse(new[]
+                { PointData.Measurement("h2o").Field("water_level", 9.0D) });
+        }
+
         private string GetRequestBody(RestResponse restResponse)
         {
             var bytes = (byte[])restResponse.Request?.Parameters

Client/WriteApiAsync.cs

@@ -95,10 +95,12 @@ public Task<RestResponse> WriteRecordsAsyncWithIRestResponse(IEnumerable<string>
             WritePrecision precision = WritePrecision.Ns, string bucket = null, string org = null,
             CancellationToken cancellationToken = default)
         {
+            var options = new BatchWriteOptions(bucket ?? _options.Bucket, org ?? _options.Org, precision);
             var batch = records
-                .Select(it => new BatchWriteRecord(new BatchWriteOptions(bucket, org, precision), it));
+                .Select(it => new BatchWriteRecord(options, it));
 
-            return WriteDataAsyncWithIRestResponse(batch, bucket, org, precision, cancellationToken);
+            return WriteDataAsyncWithIRestResponse(batch, options.Bucket, options.OrganizationId, precision,
+                cancellationToken);
         }
 
         /// <summary>
@@ -169,12 +171,13 @@ public Task<RestResponse[]> WritePointsAsyncWithIRestResponse(IEnumerable<PointD
             var tasks = new List<Task<RestResponse>>();
             foreach (var grouped in points.GroupBy(it => it.Precision))
             {
-                var options = new BatchWriteOptions(bucket, org, grouped.Key);
+                var options = new BatchWriteOptions(bucket ?? _options.Bucket, org ?? _options.Org, grouped.Key);
                 var groupedPoints = grouped
                     .Select(it => new BatchWritePoint(options, _options, it))
                     .ToList();
 
-                tasks.Add(WriteDataAsyncWithIRestResponse(groupedPoints, bucket, org, grouped.Key, cancellationToken));
+                tasks.Add(WriteDataAsyncWithIRestResponse(groupedPoints, options.Bucket, options.OrganizationId,
+                    grouped.Key, cancellationToken));
             }
 
             return Task.WhenAll(tasks);