private object PopulateObject()

in src/Elastic.Apm/Libraries/Newtonsoft.Json/Serialization/JsonSerializerInternalReader.cs [2128:2236]
89 lines of code
31 McCabe index (conditional complexity)

		private object PopulateObject(object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty? member, string? id)
		{
			OnDeserializing(reader, contract, newObject);

			// only need to keep a track of properties' presence if they are required or a value should be defaulted if missing
			var propertiesPresence = contract.HasRequiredOrDefaultValueProperties
				|| HasFlag(Serializer._defaultValueHandling, DefaultValueHandling.Populate)
					? contract.Properties.ToDictionary(m => m, m => PropertyPresence.None)
					: null;

			if (id != null) AddReference(reader, id, newObject);

			var initialDepth = reader.Depth;

			var finished = false;
			do
				switch (reader.TokenType)
				{
					case JsonToken.PropertyName:
					{
						var propertyName = reader.Value!.ToString();

						if (CheckPropertyName(reader, propertyName)) continue;

						try
						{
							// attempt exact case match first
							// then try match ignoring case
							var property = contract.Properties.GetClosestMatchProperty(propertyName);

							if (property == null)
							{
								if (TraceWriter != null && TraceWriter.LevelFilter >= TraceLevel.Verbose)
									TraceWriter.Trace(TraceLevel.Verbose,
										JsonPosition.FormatMessage(reader as IJsonLineInfo, reader.Path,
											"Could not find member '{0}' on {1}".FormatWith(CultureInfo.InvariantCulture, propertyName,
												contract.UnderlyingType)), null);

								if ((contract.MissingMemberHandling ?? Serializer._missingMemberHandling) == MissingMemberHandling.Error)
									throw JsonSerializationException.Create(reader,
										"Could not find member '{0}' on object of type '{1}'".FormatWith(CultureInfo.InvariantCulture, propertyName,
											contract.UnderlyingType.Name));

								if (!reader.Read()) break;

								SetExtensionData(contract, member, reader, propertyName, newObject);
								continue;
							}

							if (property.Ignored || !ShouldDeserialize(reader, property, newObject))
							{
								if (!reader.Read()) break;

								SetPropertyPresence(reader, property, propertiesPresence);
								SetExtensionData(contract, member, reader, propertyName, newObject);
							}
							else
							{
								if (property.PropertyContract == null) property.PropertyContract = GetContractSafe(property.PropertyType);

								var propertyConverter = GetConverter(property.PropertyContract, property.Converter, contract, member);

								if (!reader.ReadForType(property.PropertyContract, propertyConverter != null))
									throw JsonSerializationException.Create(reader,
										"Unexpected end when setting {0}'s value.".FormatWith(CultureInfo.InvariantCulture, propertyName));

								SetPropertyPresence(reader, property, propertiesPresence);

								// set extension data if property is ignored or readonly
								if (!SetPropertyValue(property, propertyConverter, contract, member, reader, newObject))
									SetExtensionData(contract, member, reader, propertyName, newObject);
							}
						}
						catch (Exception ex)
						{
							if (IsErrorHandled(newObject, contract, propertyName, reader as IJsonLineInfo, reader.Path, ex))
								HandleError(reader, true, initialDepth);
							else
								throw;
						}
						break;
					}
					case JsonToken.EndObject:
						finished = true;
						break;
					case JsonToken.Comment:
						// ignore
						break;
					default:
						throw JsonSerializationException.Create(reader, "Unexpected token when deserializing object: " + reader.TokenType);
				}
			while (!finished && reader.Read());

			if (!finished) ThrowUnexpectedEndException(reader, contract, newObject, "Unexpected end when deserializing object.");

			if (propertiesPresence != null)
			{
				foreach (var propertyPresence in propertiesPresence)
				{
					var property = propertyPresence.Key;
					var presence = propertyPresence.Value;

					EndProcessProperty(newObject, reader, contract, initialDepth, property, presence, true);
				}
			}

			OnDeserialized(reader, contract, newObject);
			return newObject;
		}