Exception raised when Type is null

[sebbrochet]

Get a Null Reference Exception inside DeltaKustoLib.KustoModel.MappingModel.MappingElement.Equals method when other.DataType is Null.

delta-kusto 0.10.2

Activating Client...
Client Activated
Newer clients available:  0.10.2.109
Loading parameters at 'XXX\rev-engineer-parameters.yaml'
2 jobs
Job 'download-dev':

Compute Delta...
829 commands in delta
Processing delta commands...
Delta processed / Job completed

Job 'delta-dev':

Compute Delta...
Exception registered with Session ID '142c3da0-d32f-4040-8f2f-ca94eef05edd'
Exception encountered:  System.NullReferenceException ; Object reference not set to an instance of an object.
Stack trace:     at DeltaKustoLib.KustoModel.MappingModel.MappingElement.Equals(Object obj) in C:\repos\delta-kusto\code\DeltaKustoLib\KustoModel\MappingModel.cs:line 79
   at System.Linq.Enumerable.SequenceEqual[TSource](IEnumerable`1 first, IEnumerable`1 second, IEqualityComparer`1 comparer)
   at System.Linq.Enumerable.SequenceEqual[TSource](IEnumerable`1 first, IEnumerable`1 second)
   at DeltaKustoLib.KustoModel.MappingModel.MappingAsJsonEquals(QuotedText otherMappingAsJson) in C:\repos\delta-kusto\code\DeltaKustoLib\KustoModel\MappingModel.cs:line 180
   at DeltaKustoLib.KustoModel.MappingModel.Equals(Object obj) in C:\repos\delta-kusto\code\DeltaKustoLib\KustoModel\MappingModel.cs:line 120
   at DeltaKustoLib.DeltaHelper.GetUpdated[M,K](IEnumerable`1 currents, IEnumerable`1 targets, Func`2 keyExtractor)+MoveNext() in C:\repos\delta-kusto\code\DeltaKustoLib\DeltaHelper.cs:line 50
   at System.Linq.Enumerable.SelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.ConcatIterator`1.MoveNext()
   at System.Linq.Enumerable.SelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.ConcatIterator`1.MoveNext()
   at DeltaKustoLib.KustoModel.TableModel.ComputeDelta(TableModel targetModel)+MoveNext() in C:\repos\delta-kusto\code\DeltaKustoLib\KustoModel\TableModel.cs:line 334
   at System.Linq.Enumerable.SelectManySingleSelectorIterator`2.MoveNext()
   at System.Linq.Enumerable.ConcatIterator`1.MoveNext()
   at System.Collections.Generic.LargeArrayBuilder`1.AddRange(IEnumerable`1 items)
   at System.Collections.Generic.SparseArrayBuilder`1.ReserveOrAdd(IEnumerable`1 items)
   at System.Linq.Enumerable.ConcatNIterator`1.LazyToArray()
   at System.Linq.Enumerable.ConcatNIterator`1.ToArray()
   at System.Collections.Immutable.ImmutableArray.CreateRange[T](IEnumerable`1 items)
   at DeltaKustoLib.KustoModel.DatabaseModel.ComputeDelta(DatabaseModel targetModel) in C:\repos\delta-kusto\code\DeltaKustoLib\KustoModel\DatabaseModel.cs:line 191
   at delta_kusto.DeltaOrchestration.ProcessJobAsync(MainParameterization parameters, IKustoManagementGatewayFactory kustoGatewayFactory, IFileGateway localFileGateway, String jobName, JobParameterization job) in C:\repos\delta-kusto\code\delta-kusto\DeltaOrchestration.cs:line 143
   at delta_kusto.DeltaOrchestration.ComputeDeltaAsync(String parameterFilePath, IEnumerable`1 pathOverrides) in C:\repos\delta-kusto\code\delta-kusto\DeltaOrchestration.cs:line 82
   at delta_kusto.DeltaOrchestration.ComputeDeltaAsync(String parameterFilePath, IEnumerable`1 pathOverrides) in C:\repos\delta-kusto\code\delta-kusto\DeltaOrchestration.cs:line 106
   at delta_kusto.DeltaOrchestration.ComputeDeltaAsync(String parameterFilePath, IEnumerable`1 pathOverrides) in C:\repos\delta-kusto\code\delta-kusto\DeltaOrchestration.cs:line 110
   at delta_kusto.Program.RunOptionsAsync(CommandLineOptions options) in C:\repos\delta-kusto\code\delta-kusto\Program.cs:line 120
   at CommandLine.ParserResultExtensions.WithParsedAsync[T](ParserResult`1 result, Func`2 action)
   at delta_kusto.Program.Main(String[] args) in C:\repos\delta-kusto\code\delta-kusto\Program.cs:line 51

Was able to work around it with this "fix":

public override bool Equals(object? obj)
{
    var other = obj as MappingElement;
    var result = other != null
        && other.Column.Equals(Column)
        && other.DataType != null && other.DataType.Equals(DataType)
        && other.Properties.Equals(Properties);

    return result;
}

[vplauzon]

Good catch. Fixed in 0.10.3.