[LSG] LoggerMessage source generator generates error when using template destructuring

[gingters]

Description

When using serilog object destructuring in a LoggerMessage template, the source generator won't recognize the parameter.

Reproduction Steps

Add this log message to a partial class:

[LoggerMessage(2020, LogLevel.Trace, "Transporting {@Response}")]
partial void LogTransporting(object response);

Expected behavior

The source generator should generate the logging method.

Actual behavior

The source generator creates an error: [SYSLIB1014] Template '@Response' is not provided as argument to the logging method

Regression?

No response

Known Workarounds

None. Using @ before the parameter name (as you would to escape reserved words) does not help.

Configuration

.NET 6.0.300

Other information

No response

[ghost]

Tagging subscribers to this area: @dotnet/area-extensions-logging
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Issue Details

---

Description

When using serilog object destructuring in a LoggerMessage template, the source generator won't recognize the parameter.

Reproduction Steps

Add this log message to a partial class:

[LoggerMessage(2020, LogLevel.Trace, "Transporting {@Response}")]
partial void LogTransporting(object response);

Expected behavior

The source generator should generate the logging method.

Actual behavior

The source generator creates an error: [SYSLIB1014] Template '@Response' is not provided as argument to the logging method

Regression?

No response

Known Workarounds

None. Using @ before the parameter name (as you would to escape reserved words) does not help.

Configuration

.NET 6.0.300

Other information

No response

Author:	gingters
Assignees:	-
Labels:	untriaged, area-Extensions-Logging
Milestone:	-

[maryamariyan]

Looking

[maryamariyan]

fyi, as part of the bugfix in #60968 we fixed the sample case below:

    [LoggerMessage(EventId = 2020, Level = LogLevel.Trace, Message = "Transporting {Response}")]
    public static partial void LogTransporting(ILogger logger, string @response);

Where at sign goes over the method variable not the message template argument.
Wondering if it is a common scenario to have @ as part of the message templates. Also noticed an example in https://messagetemplates.org/

[tarekgh]

This should be already fixed by #79038