[OneCollector] Dictionary serialization issue

[MattHyman]

Component

OpenTelemetry.Exporter.OneCollector

Package Version

Package Name	Version
OpenTelemetry.Api	1.8.0
OpenTelemetry	1.8.0
TBD	TBD

Runtime Version

1.9.2

Description

One Collector Exporter double serializing Dictionary payload with loggerMessage

Steps to Reproduce

Use LoggerMessage and Otel with a dictionary of objects indexed by strings. Send a message and notice how in fiddler the JSON is not being formed/parsed corectly.

[LoggerMessage(LogLevel.Debug, EventName = "ExtensionInitialized")]
public static partial void SendExtensionInitializedEvent(this ILogger logger, Dictionary<string, object> payload);

Expected Result

When direct logging is used everything is formed/parsed correctly.

otelLogger.Log(LogLevel.Information, new EventId(0, eventName), "{EventName}{Payload}", eventName, payload);

Actual Result

Use LoggerMessage and Otel with a dictionary of objects indexed by strings. Send a message and notice how in fiddler the JSON is not being formed/parsed corectly.

[LoggerMessage(LogLevel.Debug, EventName = "ExtensionInitialized")]
public static partial void SendExtensionInitializedEvent(this ILogger logger, Dictionary<string, object> payload);

Additional Context

We have found a partial mitigation via
[LogProperties(OmitReferenceName = true)] as described in documentation.

[LoggerMessage(LogLevel.Information, EventName = "WidgetActionStarted")]
public static partial void SendWidgetActionStartedEvent(this ILogger logger, [LogProperties(OmitReferenceName = true)] WidgetActionTelemetryEvent payload);

[sstulman]

I am seeing this also.