MetricsAssertions 0.1.0

Prefix Reserved
.NET 10.0 This package targets .NET 10.0. The package is compatible with this framework or higher. 
dotnet add package MetricsAssertions --version 0.1.0
                    


                    

                
NuGet\Install-Package MetricsAssertions -Version 0.1.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="MetricsAssertions" Version="0.1.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="MetricsAssertions" Version="0.1.0" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="MetricsAssertions" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add MetricsAssertions --version 0.1.0
                    


                    

                
#r "nuget: MetricsAssertions, 0.1.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package MetricsAssertions@0.1.0
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=MetricsAssertions&version=0.1.0
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=MetricsAssertions&version=0.1.0
                    


                            Install as a Cake Tool

MetricsAssertions

NuGet License: MIT .NET

Scope: Test projects only. Not intended for production code.

Framework-agnostic core for fluent metric-measurement assertions over System.Diagnostics.Metrics instruments, built on the first-party MetricCollector testing primitive. Test-framework assertion entry points live in adapter packages; MetricsAssertions.TUnit ships today.

What ships

  • InstrumentCapture captures a referenceable, observable, or by-name instrument (Of / OfObservable / OfName) via MetricCollector<T>, with totals, last value, tag queries, baseline deltas (Snapshot / Since), and WaitForAsync.
  • MeasurementSet: an immutable, queryable set of measurements with counter and histogram aggregates, sample comparisons, tag and instrument narrowing, and a deterministic snapshot projection.
  • MeterCapture (meter-wide capture across instruments) and MeterInspector (instrument discovery).
  • CapturedMeasurement (instrument name, value projected to double, tags, timestamp).

Install

# Most consumers install a test-framework adapter, which pulls this in transitively:
dotnet add package MetricsAssertions.TUnit

The full reference is in the GitHub README.

License

MIT.

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on MetricsAssertions:

Package Downloads
MetricsAssertions.TUnit

TUnit-native fluent metric-assertion DSL over System.Diagnostics.Metrics instruments for .NET tests: Assert.That(capture) entry points generated via the GenerateAssertion source generator. Measurement capture is the first-party MetricCollector testing primitive wrapped in a per-test InstrumentCapture. Builds on the MetricsAssertions framework-agnostic core. AOT-compatible, trimmable, no runtime reflection in the assertion path.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
0.1.0 90 6/7/2026
0.0.1 140 6/7/2026

View the rendered release notes: https://github.com/JohnVerheij/MetricsAssertions.TUnit/releases/tag/v0.1.0

The full surface: a queryable `MeasurementSet`, multi-instrument `MeterCapture`, meter-introspection
`MeterInspector`, baseline deltas, and the complete `Assert.That` assertion vocabulary across all three.

### Added

- **`MeasurementSet` (core):** an immutable, queryable set of captured measurements with counter-style
 (`Total`) and histogram-style (`Sum`/`Min`/`Max`/`Average`) aggregates, raw `Values`/`All`, ordered and
 order-insensitive sample comparisons, tag and instrument narrowing (`Tagged`/`ForInstrument`), range and
 tag predicates, and a deterministic `ToSnapshotString` projection.
- **`MeterCapture` (core):** a meter-wide bundle composed from per-instrument captures, built fluently
 with `For` + `Add`, queried per instrument or across all via `Measurements`, with `RecordObservable`
 for observable gauges.
- **`MeterInspector` (core):** discovers which instruments a meter publishes
 (`PublishedInstrumentNames`/`IsPublished`/`PublishesAll`) via a short-lived `MeterListener`.
- **`InstrumentCapture` (core):** expanded with `OfName`/`OfObservable` construction, `Total`/`LastValue`,
 tag queries (`Tagged`/`HasMeasurementTagged`), baseline deltas (`Snapshot`/`Since` + `MeasurementBaseline`),
 `RecordObservable`, and `WaitForAsync`.
- **`MetricsAssertions.TUnit` (adapter):** the full `Assert.That(...).Has*` vocabulary (counter and
 up-down-counter totals, measurement counts, emptiness, last value, histogram sum/average/range, exact and
 order-insensitive sample sets, and tag-consistency) over `InstrumentCapture`, `MeasurementSet`, and
 `MeterCapture`.
- **Failure diagnostics:** every assertion dumps the captured measurements (instrument, value, tags,
 timestamp) under the failure, so a mismatch shows what was actually recorded, not only the mismatched
 scalar.
- **Hardening:** tolerance arguments are validated (finite, non-negative), inverted range bounds are
 rejected, baselines are bound to their originating capture, duplicate `MeterCapture` instrument names
 dispose the prior capture, and unknown meter-capture instruments fail as assertions rather than throwing.

### Changed

- **Breaking:** `InstrumentCapture.Measurements` now returns a `MeasurementSet` instead of
 `IReadOnlyList<CapturedMeasurement>`. Use `Measurements.All` for the underlying list, or the new query
 surface directly.