[Exporter.Prometheus] Add ScopeInfoEnabled option

[martincostello]

Fixes #5725.
Fixes #7157.

Changes

• Add new ScopeInfoEnabled option that allows a user to opt-out of scope information being written to the scrape response.
• Improve tests by adding snapshots and simplifying naming.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

❌ Patch coverage is 96.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.98%. Comparing base (6b4c6fc) to head (8cffbbd).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...ometheus.AspNetCore/PrometheusAspNetCoreOptions.cs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7436      +/-   ##
==========================================
+ Coverage   89.93%   89.98%   +0.04%     
==========================================
  Files         283      278       -5     
  Lines       15183    14667     -516     
==========================================
- Hits        13655    13198     -457     
+ Misses       1528     1469      -59     

Flag	Coverage Δ
unittests-PowerShellScripts	?
unittests-Project-Experimental	89.89% <96.00%> (-0.02%)	⬇️
unittests-Project-Stable	89.95% <96.00%> (-0.02%)	⬇️
unittests-UnstableCoreLibraries-Experimental	48.85% <96.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ner/Internal/Shared/PrometheusCollectionManager.cs	90.35% <100.00%> (+0.08%)	⬆️
...HttpListener/Internal/Shared/PrometheusExporter.cs	100.00% <100.00%> (ø)
...tener/Internal/Shared/PrometheusExporterOptions.cs	100.00% <100.00%> (ø)
...rnal/Shared/Serialization/OpenMetricsSerializer.cs	100.00% <100.00%> (ø)
...l/Shared/Serialization/PrometheusTextSerializer.cs	100.00% <ø> (ø)
...ernal/Shared/Serialization/TextFormatSerializer.cs	100.00% <100.00%> (ø)
...hared/Serialization/TextFormatSerializerOptions.cs	100.00% <100.00%> (ø)
...theusHttpListenerMeterProviderBuilderExtensions.cs	81.81% <100.00%> (+0.56%)	⬆️
...heus.HttpListener/PrometheusHttpListenerOptions.cs	100.00% <100.00%> (ø)
...ometheus.AspNetCore/PrometheusAspNetCoreOptions.cs	50.00% <50.00%> (ø)

... and 10 files with indirect coverage changes

[Copilot]

Pull request overview

Adds a ScopeInfoEnabled configuration option to the Prometheus exporters (HttpListener + ASP.NET Core) so users can opt out of emitting otel_scope_* labels in scrape responses, aligning with the Prometheus/OpenMetrics compatibility guidance.

Changes:

• Introduces ScopeInfoEnabled on PrometheusHttpListenerOptions and PrometheusAspNetCoreOptions (default true) and wires it into the exporter pipeline.
• Threads a new TextFormatSerializerOptions through serialization to suppress scope labels when disabled.
• Refactors/expands tests to snapshot-based verification for the new behavior and updated integration scenarios.

Reviewed changes

Copilot reviewed 52 out of 53 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/PrometheusSerializerTests.cs	Adds unit coverage for suppressing scope labels during metric serialization.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/PrometheusHttpListenerTests.cs	Updates integration tests and adds snapshot verification (including ScopeInfoEnabled scenarios).
test/OpenTelemetry.Exporter.Prometheus.AspNetCore.Tests/PrometheusExporterMiddlewareTests.cs	Updates ASP.NET Core integration tests and adds snapshot verification (including ScopeInfoEnabled scenarios).
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.WriteMetricSupportsScopeInfoEnabledOptionForCounters_useOpenMetrics=True_suppressScopeInfo=True.verified.txt	Snapshot baseline for serialization with scope info suppressed (OpenMetrics).
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.WriteMetricSupportsScopeInfoEnabledOptionForCounters_useOpenMetrics=True_suppressScopeInfo=False.verified.txt	Snapshot baseline for serialization with scope info enabled (OpenMetrics).
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.WriteMetricSupportsScopeInfoEnabledOptionForCounters_useOpenMetrics=False_suppressScopeInfo=True.verified.txt	Snapshot baseline for serialization with scope info suppressed (Prometheus text).
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.WriteMetricSupportsScopeInfoEnabledOptionForCounters_useOpenMetrics=False_suppressScopeInfo=False.verified.txt	Snapshot baseline for serialization with scope info enabled (Prometheus text).
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithTextPlainResponseAndMeterTags.verified.text	Snapshot baseline for text/plain scrape with meter tags.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithTextPlainResponse.verified.text	Snapshot baseline for text/plain scrape.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithScrapeEndpointPathOverride.verified.text	Snapshot baseline for path override behavior.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithScrapeEndpointPathFallbackFromAddPrometheusExporter.verified.text	Snapshot baseline for options fallback via AddPrometheusExporter.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithScrapeEndpointPathFallback.verified.text	Snapshot baseline for scrape endpoint path fallback.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithScopeInfoEnabledConfigured_scopeInfoEnabled=True.verified.text	Snapshot baseline when scope labels are enabled.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithScopeInfoEnabledConfigured_scopeInfoEnabled=False.verified.text	Snapshot baseline when scope labels are disabled.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithPathNamedOptionsOverride.verified.text	Snapshot baseline for named-options overrides.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithOpenMetricsVersionHeaderAndMeterTags.verified.text	Snapshot baseline for OpenMetrics negotiation with meter tags.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithOpenMetricsVersionHeader.verified.text	Snapshot baseline for OpenMetrics negotiation.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithNoMetrics.verified.text	Snapshot baseline for “no metrics” scrape.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMixedPredicateAndPath.verified.text	Snapshot baseline for mixed predicate/path configuration.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMixedPath.verified.text	Snapshot baseline for mixed path configuration.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMeterProvider.verified.text	Snapshot baseline for custom meter provider usage.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMapPrometheusScrapingEndpointWithPathOverride.verified.text	Snapshot baseline for endpoint mapping with path override.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMapPrometheusScrapingEndpointWithPathNamedOptionsOverride.verified.text	Snapshot baseline for endpoint mapping with named options.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMapPrometheusScrapingEndpointWithMeterProvider.verified.text	Snapshot baseline for endpoint mapping with external meter provider.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithMapPrometheusScrapingEndpoint.verified.text	Snapshot baseline for endpoint mapping defaults.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithHttpContextPredicate.verified.text	Snapshot baseline for scrape predicate behavior.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithDefaultOptions.verified.text	Snapshot baseline for ASP.NET Core default scrape behavior.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunWithCustomScrapeEndpointPath.verified.text	Snapshot baseline for custom scrape path in ASP.NET Core.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithScopeInfoEnabledConfigured_scopeInfoEnabled=True.verified.text	Snapshot baseline for HttpListener server with scope labels enabled.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithScopeInfoEnabledConfigured_scopeInfoEnabled=False.verified.text	Snapshot baseline for HttpListener server with scope labels disabled.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithOpenMetricsVersionHeaderAndMeterTags.verified.text	Snapshot baseline for HttpListener server OpenMetrics + meter tags.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithOpenMetricsVersionHeader.verified.text	Snapshot baseline for HttpListener server OpenMetrics.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithNoMetrics.verified.text	Snapshot baseline for HttpListener server with no metrics.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithNoAcceptHeaderAndMeterTags.verified.text	Snapshot baseline for HttpListener server Prometheus text + meter tags.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithNoAcceptHeader.verified.text	Snapshot baseline for HttpListener server Prometheus text.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.RunHttpServerWithDefaultOptions.verified.text	Snapshot baseline for HttpListener server default behavior.
test/OpenTelemetry.Exporter.Prometheus.HttpListener.Tests/snapshots/PrometheusSerializer.BufferSizeIncreasesWithLotOfMetrics.verified.text	Snapshot baseline for large-payload/buffer growth scenario.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/PrometheusHttpListenerOptions.cs	Adds public ScopeInfoEnabled option (default true).
src/OpenTelemetry.Exporter.Prometheus.HttpListener/PrometheusHttpListenerMeterProviderBuilderExtensions.cs	Wires ScopeInfoEnabled from listener options into exporter options.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/PrometheusExporterOptions.cs	Adds internal ScopeInfoEnabled plumbing (default true).
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/PrometheusExporter.cs	Stores ScopeInfoEnabled on the exporter instance.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/PrometheusCollectionManager.cs	Passes suppression intent into serialization via TextFormatSerializerOptions.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/Serialization/TextFormatSerializerOptions.cs	Introduces serializer options struct (includes SuppressScopeInfo).
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/Serialization/TextFormatSerializer.cs	Threads serializer options into tag writing and created-series paths.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/Serialization/OpenMetricsSerializer.cs	Updates created-series writing to propagate serializer options.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/Internal/Shared/Serialization/PrometheusTextSerializer.cs	Updates created-series writing signature to accept serializer options.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/README.md	Documents ScopeInfoEnabled.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/CHANGELOG.md	Notes the new ScopeInfoEnabled option.
src/OpenTelemetry.Exporter.Prometheus.HttpListener/.publicApi/PublicAPI.Unshipped.txt	Tracks the new public API on PrometheusHttpListenerOptions.
src/OpenTelemetry.Exporter.Prometheus.AspNetCore/PrometheusAspNetCoreOptions.cs	Adds ScopeInfoEnabled surface for ASP.NET Core options.
src/OpenTelemetry.Exporter.Prometheus.AspNetCore/README.md	Documents ScopeInfoEnabled for ASP.NET Core exporter.
src/OpenTelemetry.Exporter.Prometheus.AspNetCore/CHANGELOG.md	Notes the new ScopeInfoEnabled option.
src/OpenTelemetry.Exporter.Prometheus.AspNetCore/.publicApi/PublicAPI.Unshipped.txt	Tracks the new public API on PrometheusAspNetCoreOptions.

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