go.opentelemetry.io/otel/sdk/metric v1.44.0: Instrument

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify go.opentelemetry.io/otel/sdk/metric.Instrument in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/sdk/metric.Instrument

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:bf2f319e4330910b2bfca11df14b7de5c0a0a77f0f9cc1c5717b2a9f92733776","contract":["Instrument.IsEmpty returns true for a zero-value Instrument and false when any property is populated","NewView with populated Instrument criteria matches instruments having identical non-zero properties and returns configured stream","NewView with empty Instrument criteria returns a view matching no instruments","View receives populated Instrument with correct Name, Kind, Unit, Description, and Scope during Meter instrument registration"],"goal":"verify go.opentelemetry.io/otel/sdk/metric.Instrument in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk/metric.Instrument"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0","symbols":["go.opentelemetry.io/otel/sdk/metric.Instrument"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	go.opentelemetry.io/otel/metric v1.44.0
	go.opentelemetry.io/otel/sdk/metric v1.44.0
)

require (
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/uuid v1.6.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel v1.44.0 // indirect
	go.opentelemetry.io/otel/sdk v1.44.0 // indirect
	go.opentelemetry.io/otel/trace v1.44.0 // indirect
	golang.org/x/sys v0.45.0 // indirect
)

github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/otel v1.44.0 h1:JjwHmHpA4iZ3wBxluu2fbbE7j4kqlE8jXyAyPXH7HqU=
go.opentelemetry.io/otel v1.44.0/go.mod h1:BMgjTHL9WPRlRjL2oZCBTL4whCGtXch2H4BhOPIAyYc=
go.opentelemetry.io/otel/metric v1.44.0 h1:1w0gILTcHdr3YI+ixLyjemwrVnsMURbTZFrSYCdDdmc=
go.opentelemetry.io/otel/metric v1.44.0/go.mod h1:8O7hanEPBNgEMmybD3s2VBKcgWOCsA6tzHBPODAiquo=
go.opentelemetry.io/otel/metric/x v0.66.0 h1:YkCrx1zLOChi9ZcZ6euupOcsgzbVlec7D/xoEU1+cTA=
go.opentelemetry.io/otel/metric/x v0.66.0/go.mod h1:d1+BDj9t96do0/1LoU1ayfCv79ZgNE41qbhBvnMOBZk=
go.opentelemetry.io/otel/sdk v1.44.0 h1:nHYwb9lK+fJPU/dnT6s7W7Z8itMWyqrnVfbheVYrZ58=
go.opentelemetry.io/otel/sdk v1.44.0/go.mod h1:Osuydd3Se74nqjAKxid74N5eC+jfEqfTegHRnq58oK0=
go.opentelemetry.io/otel/sdk/metric v1.44.0 h1:3LlKgI+VjbVsjNRFZJZAJ30WjXC5VkNRks6si09iEfI=
go.opentelemetry.io/otel/sdk/metric v1.44.0/go.mod h1:5B5pMARnXxKhltooO4xUuCBorl65a4EpnTalObqOigA=
go.opentelemetry.io/otel/trace v1.44.0 h1:jxF5CsGYCe74MCRx2X4g7WsY/VBKRqqpNvXlX/6gtIk=
go.opentelemetry.io/otel/trace v1.44.0/go.mod h1:oLl1jrMQAVo6v3GAggN+1VH9VIz9iUSvW53sW1Q8PIE=
golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel/metric"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"
)

func main() {
	ctx := context.Background()

	// 1. Inspect a zero-value Instrument
	var zeroInst sdkmetric.Instrument
	fmt.Printf("zero-value Instrument IsEmpty: %t\n", zeroInst.IsEmpty())

	// 2. Define criteria using sdkmetric.Instrument
	criteria := sdkmetric.Instrument{
		Name: "requests_total",
		Kind: sdkmetric.InstrumentKindCounter,
	}

	// 3. Define a Stream mask to rename the metric stream
	mask := sdkmetric.Stream{
		Name:        "http_server_requests_total",
		Description: "Renamed total HTTP requests stream",
	}

	// 4. Create a View matching the criteria
	view := sdkmetric.NewView(criteria, mask)

	// 5. Configure MeterProvider with the View
	reader := sdkmetric.NewManualReader()
	provider := sdkmetric.NewMeterProvider(
		sdkmetric.WithReader(reader),
		sdkmetric.WithView(view),
	)
	defer func() {
		_ = provider.Shutdown(ctx)
	}()

	meter := provider.Meter("sample-telemetry")
	counter, err := meter.Int64Counter(
		"requests_total",
		metric.WithDescription("Original requests counter"),
		metric.WithUnit("requests"),
	)
	if err != nil {
		panic(err)
	}

	counter.Add(ctx, 1)

	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err != nil {
		panic(err)
	}

	for _, sm := range rm.ScopeMetrics {
		for _, m := range sm.Metrics {
			fmt.Printf("Collected metric stream: %s (%s)\n", m.Name, m.Description)
		}
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/metric.Instrument in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/sdk/metric.Instrument"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/metric"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
)

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract verification failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All go.opentelemetry.io/otel/sdk/metric.Instrument contract assertions passed.")
}

func runContract() error {
	// Assertion 1: Instrument.IsEmpty returns true for a zero-value Instrument and false when any property is populated
	var zeroInst sdkmetric.Instrument
	if !zeroInst.IsEmpty() {
		return fmt.Errorf("assertion 1 failed: expected zero-value Instrument.IsEmpty() to be true, got false")
	}

	populatedInst := sdkmetric.Instrument{
		Name: "active_tasks",
	}
	if populatedInst.IsEmpty() {
		return fmt.Errorf("assertion 1 failed: expected populated Instrument.IsEmpty() to be false, got true")
	}

	// Assertion 2: NewView with populated Instrument criteria matches instruments having identical non-zero properties and returns configured stream
	criteria := sdkmetric.Instrument{
		Name: "requests_total",
		Kind: sdkmetric.InstrumentKindCounter,
	}
	mask := sdkmetric.Stream{
		Name:        "custom_requests_total",
		Description: "Custom description for total requests",
	}
	view := sdkmetric.NewView(criteria, mask)

	matchingCandidate := sdkmetric.Instrument{
		Name: "requests_total",
		Kind: sdkmetric.InstrumentKindCounter,
		Unit: "requests",
	}
	stream, matched := view(matchingCandidate)
	if !matched {
		return fmt.Errorf("assertion 2 failed: expected view to match instrument with matching name and kind")
	}
	if stream.Name != "custom_requests_total" {
		return fmt.Errorf("assertion 2 failed: expected stream name %q, got %q", "custom_requests_total", stream.Name)
	}
	if stream.Description != "Custom description for total requests" {
		return fmt.Errorf("assertion 2 failed: expected stream description %q, got %q", "Custom description for total requests", stream.Description)
	}

	nonMatchingCandidate := sdkmetric.Instrument{
		Name: "requests_latency",
		Kind: sdkmetric.InstrumentKindHistogram,
	}
	_, matchedNon := view(nonMatchingCandidate)
	if matchedNon {
		return fmt.Errorf("assertion 2 failed: expected view not to match instrument with different name and kind")
	}

	// Assertion 3: NewView with empty Instrument criteria returns a view matching no instruments
	var emptyCriteria sdkmetric.Instrument
	emptyView := sdkmetric.NewView(emptyCriteria, sdkmetric.Stream{Name: "dropped_stream"})
	_, matchedEmpty := emptyView(matchingCandidate)
	if matchedEmpty {
		return fmt.Errorf("assertion 3 failed: expected empty criteria view not to match any instrument")
	}

	// Assertion 4: View receives populated Instrument with correct Name, Kind, Unit, Description, and Scope during Meter instrument registration
	var capturedInst sdkmetric.Instrument
	captureView := func(i sdkmetric.Instrument) (sdkmetric.Stream, bool) {
		if i.Name == "payload_bytes" {
			capturedInst = i
		}
		return sdkmetric.Stream{}, false
	}

	reader := sdkmetric.NewManualReader()
	provider := sdkmetric.NewMeterProvider(
		sdkmetric.WithReader(reader),
		sdkmetric.WithView(captureView),
	)
	defer func() {
		_ = provider.Shutdown(context.Background())
	}()

	meter := provider.Meter(
		"contract-meter",
		metric.WithInstrumentationVersion("v1.2.3"),
	)
	_, err := meter.Int64UpDownCounter(
		"payload_bytes",
		metric.WithDescription("Size of in-flight payload in bytes"),
		metric.WithUnit("By"),
	)
	if err != nil {
		return fmt.Errorf("assertion 4 failed: meter.Int64UpDownCounter error: %w", err)
	}

	if capturedInst.IsEmpty() {
		return fmt.Errorf("assertion 4 failed: expected captured Instrument to be populated")
	}
	if capturedInst.Name != "payload_bytes" {
		return fmt.Errorf("assertion 4 failed: expected Instrument Name %q, got %q", "payload_bytes", capturedInst.Name)
	}
	if capturedInst.Kind != sdkmetric.InstrumentKindUpDownCounter {
		return fmt.Errorf("assertion 4 failed: expected Instrument Kind %v, got %v", sdkmetric.InstrumentKindUpDownCounter, capturedInst.Kind)
	}
	if capturedInst.Unit != "By" {
		return fmt.Errorf("assertion 4 failed: expected Instrument Unit %q, got %q", "By", capturedInst.Unit)
	}
	if capturedInst.Description != "Size of in-flight payload in bytes" {
		return fmt.Errorf("assertion 4 failed: expected Instrument Description %q, got %q", "Size of in-flight payload in bytes", capturedInst.Description)
	}
	if capturedInst.Scope.Name != "contract-meter" || capturedInst.Scope.Version != "v1.2.3" {
		return fmt.Errorf("assertion 4 failed: expected Scope name 'contract-meter' and version 'v1.2.3', got %v", capturedInst.Scope)
	}

	return nil
}