Mark Activity.Tags as obsolete and/or create an analyzer

[msallin]

The Activity.Tags property only return tags which are KeyValuePair<string, string> and shouldn't be used anymore. Having both without any hints about this is confusing for the customer and might lead to mistakes.

Don't use anymore:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 271 to 280 in 79ae74f

	/// <summary>
	/// Tags are string-string key-value pairs that represent information that will
	/// be logged along with the Activity to the logging system. This information
	/// however is NOT passed on to the children of this activity.
	/// </summary>
	/// <seealso cref="Baggage"/>
	public IEnumerable<KeyValuePair<string, string?>> Tags
	{
	get => _tags?.EnumerateStringValues() ?? s_emptyBaggageTags;
	}

Use:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 282 to 289 in 79ae74f

	/// <summary>
	/// List of the tags which represent information that will be logged along with the Activity to the logging system.
	/// This information however is NOT passed on to the children of this activity.
	/// </summary>
	public IEnumerable<KeyValuePair<string, object?>> TagObjects
	{
	get => _tags ?? s_emptyTagObjects;
	}

For details see discussion with @tarekgh
#48722 (comment)

Tagging subscribers to this area: @tarekgh, @tommcdon, @pjanotti
See info in area-owners.md if you want to be subscribed.

Issue Details

---

The Activity.Tags property only return tags which are KeyValuePair<string, string> and shouldn't be used anymore. Having both without any hints about this is confusing for the customer and might lead to mistakes.

Don't use anymore:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 271 to 280 in 79ae74f

	/// <summary>
	/// Tags are string-string key-value pairs that represent information that will
	/// be logged along with the Activity to the logging system. This information
	/// however is NOT passed on to the children of this activity.
	/// </summary>
	/// <seealso cref="Baggage"/>
	public IEnumerable<KeyValuePair<string, string?>> Tags
	{
	get => _tags?.EnumerateStringValues() ?? s_emptyBaggageTags;
	}

Use:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 282 to 289 in 79ae74f

	/// <summary>
	/// List of the tags which represent information that will be logged along with the Activity to the logging system.
	/// This information however is NOT passed on to the children of this activity.
	/// </summary>
	public IEnumerable<KeyValuePair<string, object?>> TagObjects
	{
	get => _tags ?? s_emptyTagObjects;
	}

For details see discussion with @tarekgh
#48722 (comment)

Author:	msallin
Assignees:	-
Labels:	area-System.Diagnostics.Tracing, untriaged
Milestone:	-

Tagging subscribers to this area: @tarekgh
See info in area-owners.md if you want to be subscribed.

Issue Details

---

The Activity.Tags property only return tags which are KeyValuePair<string, string> and shouldn't be used anymore. Having both without any hints about this is confusing for the customer and might lead to mistakes.

Don't use anymore:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 271 to 280 in 79ae74f

	/// <summary>
	/// Tags are string-string key-value pairs that represent information that will
	/// be logged along with the Activity to the logging system. This information
	/// however is NOT passed on to the children of this activity.
	/// </summary>
	/// <seealso cref="Baggage"/>
	public IEnumerable<KeyValuePair<string, string?>> Tags
	{
	get => _tags?.EnumerateStringValues() ?? s_emptyBaggageTags;
	}

Use:

runtime/src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Activity.cs

Lines 282 to 289 in 79ae74f

	/// <summary>
	/// List of the tags which represent information that will be logged along with the Activity to the logging system.
	/// This information however is NOT passed on to the children of this activity.
	/// </summary>
	public IEnumerable<KeyValuePair<string, object?>> TagObjects
	{
	get => _tags ?? s_emptyTagObjects;
	}

For details see discussion with @tarekgh
#48722 (comment)

Author:	msallin
Assignees:	-
Labels:	area-System.Diagnostics.Activity, area-System.Diagnostics.Tracing, code-analyzer
Milestone:	-

[stephentoub]

@tarekgh, is this really a code analyzer, or are you just considering obsoleting the property if it really shouldn't be used anymore?

[tarekgh]

It is more considering obsoletion. The analyzer will be needed only if we don't obsolete it.

CC @noahfalk

[menees]

Yes, please mark Tags as obsolete in .NET 8. I couldn't find anything in the .NET 7 docs about which one to use or prefer. Finally, a web search for "activity tags vs tagobjects" linked to this issue as the 7th link down. That's too much of a treasure hunt to figure out the preferred API. An [Obsolete] attribute on Tags that said to use TagObjects instead would be much better.