go.opentelemetry.io/otel/sdk/metric v1.39.0: InstrumentKindHistogram

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.InstrumentKindHistogram in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram

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:sha256:163bd09eb2df30d352936502f68d2571dfa25d8671b14cbe3f7649f7c0803fa6","contract":["InstrumentKindHistogram has valid constant value and String representation","DefaultTemporalitySelector returns CumulativeTemporality for InstrumentKindHistogram","DefaultAggregationSelector returns AggregationExplicitBucketHistogram for InstrumentKindHistogram","NewHistogramView configures custom bucket boundaries for InstrumentKindHistogram","NewHistogramMeterProvider integrates custom view and reader for Histogram instrument"],"goal":"verify go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0","symbols":["go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram"],"verifierAdapter":"golang@1"}

module sample

go 1.24.0

require go.opentelemetry.io/otel/sdk/metric v1.39.0

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 v1.39.0 // indirect
	go.opentelemetry.io/otel/metric v1.39.0 // indirect
	go.opentelemetry.io/otel/sdk v1.39.0 // indirect
	go.opentelemetry.io/otel/trace v1.39.0 // indirect
	golang.org/x/sys v0.39.0 // 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 v1.39.0 h1:8yPrr/S0ND9QEfTfdP9V+SiwT4E0G7Y5MO7p85nis48=
go.opentelemetry.io/otel v1.39.0/go.mod h1:kLlFTywNWrFyEdH0oj2xK0bFYZtHRYUdv1NklR/tgc8=
go.opentelemetry.io/otel/metric v1.39.0 h1:d1UzonvEZriVfpNKEVmHXbdf909uGTOQjA0HF0Ls5Q0=
go.opentelemetry.io/otel/metric v1.39.0/go.mod h1:jrZSWL33sD7bBxg1xjrqyDjnuzTUB0x1nBERXd7Ftcs=
go.opentelemetry.io/otel/sdk v1.39.0 h1:nMLYcjVsvdui1B/4FRkwjzoRVsMK8uL/cj0OyhKzt18=
go.opentelemetry.io/otel/sdk v1.39.0/go.mod h1:vDojkC4/jsTJsE+kh+LXYQlbL8CgrEcwmt1ENZszdJE=
go.opentelemetry.io/otel/sdk/metric v1.39.0 h1:cXMVVFVgsIf2YL6QkRF4Urbr/aMInf+2WKg+sEJTtB8=
go.opentelemetry.io/otel/sdk/metric v1.39.0/go.mod h1:xq9HEVH7qeX69/JnwEfp6fVq5wosJsY1mt4lLfYdVew=
go.opentelemetry.io/otel/trace v1.39.0 h1:2d2vfpEDmCJ5zVYz7ijaJdOF59xLomrvj7bjt6/qCJI=
go.opentelemetry.io/otel/trace v1.39.0/go.mod h1:88w4/PnZSazkGzz/w84VHpQafiU4EtqqlVdxWy+rNOA=
golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

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

// HistogramKind returns the InstrumentKindHistogram constant.
func HistogramKind() sdkmetric.InstrumentKind {
	return sdkmetric.InstrumentKindHistogram
}

// IsHistogram checks if the given InstrumentKind is InstrumentKindHistogram.
func IsHistogram(kind sdkmetric.InstrumentKind) bool {
	return kind == sdkmetric.InstrumentKindHistogram
}

// HistogramDefaultTemporality returns the default temporality for InstrumentKindHistogram.
func HistogramDefaultTemporality() metricdata.Temporality {
	return sdkmetric.DefaultTemporalitySelector(sdkmetric.InstrumentKindHistogram)
}

// HistogramDefaultAggregation returns the default aggregation for InstrumentKindHistogram.
func HistogramDefaultAggregation() sdkmetric.Aggregation {
	return sdkmetric.DefaultAggregationSelector(sdkmetric.InstrumentKindHistogram)
}

// NewHistogramView creates a View that matches InstrumentKindHistogram and applies custom bucket boundaries.
func NewHistogramView(boundaries []float64) sdkmetric.View {
	return sdkmetric.NewView(
		sdkmetric.Instrument{
			Kind: sdkmetric.InstrumentKindHistogram,
		},
		sdkmetric.Stream{
			Aggregation: sdkmetric.AggregationExplicitBucketHistogram{
				Boundaries: boundaries,
			},
		},
	)
}

// NewHistogramMeterProvider creates a MeterProvider configured with the given reader and view.
func NewHistogramMeterProvider(reader sdkmetric.Reader, view sdkmetric.View) *sdkmetric.MeterProvider {
	return sdkmetric.NewMeterProvider(
		sdkmetric.WithReader(reader),
		sdkmetric.WithView(view),
	)
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.39.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"
	"reflect"

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

func main() {
	// Assertion 1: InstrumentKindHistogram has valid constant value and String representation
	kind := sample.HistogramKind()
	if kind != sdkmetric.InstrumentKindHistogram {
		fmt.Fprintf(os.Stderr, "FAIL: expected InstrumentKindHistogram, got %v\n", kind)
		os.Exit(1)
	}
	if !sample.IsHistogram(kind) {
		fmt.Fprintf(os.Stderr, "FAIL: IsHistogram returned false for InstrumentKindHistogram\n")
		os.Exit(1)
	}
	if kind.String() != "Histogram" {
		fmt.Fprintf(os.Stderr, "FAIL: expected String() to be 'Histogram', got %q\n", kind.String())
		os.Exit(1)
	}

	// Assertion 2: DefaultTemporalitySelector returns CumulativeTemporality for InstrumentKindHistogram
	temp := sample.HistogramDefaultTemporality()
	if temp != metricdata.CumulativeTemporality {
		fmt.Fprintf(os.Stderr, "FAIL: expected CumulativeTemporality, got %v\n", temp)
		os.Exit(1)
	}

	// Assertion 3: DefaultAggregationSelector returns AggregationExplicitBucketHistogram for InstrumentKindHistogram
	agg := sample.HistogramDefaultAggregation()
	bucketAgg, ok := agg.(sdkmetric.AggregationExplicitBucketHistogram)
	if !ok {
		fmt.Fprintf(os.Stderr, "FAIL: expected AggregationExplicitBucketHistogram, got %T\n", agg)
		os.Exit(1)
	}
	if len(bucketAgg.Boundaries) == 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-empty default boundaries for Histogram aggregation\n")
		os.Exit(1)
	}

	// Assertion 4: NewHistogramView configures custom bucket boundaries for InstrumentKindHistogram
	customBoundaries := []float64{0.1, 0.5, 1.0, 5.0}
	view := sample.NewHistogramView(customBoundaries)
	stream, matches := view(sdkmetric.Instrument{
		Name: "http_request_duration",
		Kind: sdkmetric.InstrumentKindHistogram,
	})
	if !matches {
		fmt.Fprintf(os.Stderr, "FAIL: view should match InstrumentKindHistogram\n")
		os.Exit(1)
	}
	customAgg, ok := stream.Aggregation.(sdkmetric.AggregationExplicitBucketHistogram)
	if !ok || !reflect.DeepEqual(customAgg.Boundaries, customBoundaries) {
		fmt.Fprintf(os.Stderr, "FAIL: expected custom boundaries %v, got %v\n", customBoundaries, customAgg.Boundaries)
		os.Exit(1)
	}

	// Non-histogram instrument should not match this view
	_, nonMatch := view(sdkmetric.Instrument{
		Name: "request_counter",
		Kind: sdkmetric.InstrumentKindCounter,
	})
	if nonMatch {
		fmt.Fprintf(os.Stderr, "FAIL: view should not match non-histogram InstrumentKind\n")
		os.Exit(1)
	}

	// Assertion 5: NewHistogramMeterProvider integrates custom view and reader for Histogram instrument
	reader := sdkmetric.NewManualReader()
	mp := sample.NewHistogramMeterProvider(reader, view)
	meter := mp.Meter("test-meter")
	hist, err := meter.Float64Histogram("http_request_duration")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to create Float64Histogram: %v\n", err)
		os.Exit(1)
	}
	ctx := context.Background()
	hist.Record(ctx, 0.42)

	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Collect failed: %v\n", err)
		os.Exit(1)
	}
	if len(rm.ScopeMetrics) == 0 || len(rm.ScopeMetrics[0].Metrics) == 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected recorded metrics in Collect\n")
		os.Exit(1)
	}

	if err := mp.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: meter provider Shutdown failed: %v\n", err)
		os.Exit(1)
	}

	fmt.Println("PASS: go.opentelemetry.io/otel/sdk/metric.InstrumentKindHistogram contract verified")
}