go.opentelemetry.io/otel/metric v1.24.0: WithExplicitBucketBoundaries

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/metric.WithExplicitBucketBoundaries in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries

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.

package sample

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

// HistogramInstruments holds metric instruments configured with explicit bucket boundaries.
type HistogramInstruments struct {
	Duration metric.Float64Histogram
	Payload  metric.Int64Histogram
}

// NewHistogramInstruments initializes Float64Histogram and Int64Histogram instruments
// using metric.WithExplicitBucketBoundaries.
func NewHistogramInstruments(mp metric.MeterProvider, meterName string, durationBounds []float64, payloadBounds []float64) (*HistogramInstruments, error) {
	if mp == nil {
		mp = noop.NewMeterProvider()
	}
	meter := mp.Meter(meterName)

	durationHist, err := meter.Float64Histogram(
		"http_request_duration_seconds",
		metric.WithDescription("Duration of HTTP requests in seconds"),
		metric.WithUnit("s"),
		metric.WithExplicitBucketBoundaries(durationBounds...),
	)
	if err != nil {
		return nil, fmt.Errorf("failed to create duration histogram: %w", err)
	}

	payloadHist, err := meter.Int64Histogram(
		"http_request_payload_bytes",
		metric.WithDescription("Size of HTTP request payload in bytes"),
		metric.WithUnit("By"),
		metric.WithExplicitBucketBoundaries(payloadBounds...),
	)
	if err != nil {
		return nil, fmt.Errorf("failed to create payload histogram: %w", err)
	}

	return &HistogramInstruments{
		Duration: durationHist,
		Payload:  payloadHist,
	}, nil
}

// RecordObservations records sample measurements with contextual attributes.
func (h *HistogramInstruments) RecordObservations(ctx context.Context, duration float64, payloadBytes int64, attrs ...attribute.KeyValue) {
	if h == nil {
		return
	}
	if h.Duration != nil {
		h.Duration.Record(ctx, duration, metric.WithAttributes(attrs...))
	}
	if h.Payload != nil {
		h.Payload.Record(ctx, payloadBytes, metric.WithAttributes(attrs...))
	}
}

{"case":{"caseId":"case:sha256:f8fb53f5f744b4780ea2498099b4138baa720fe96908182b45530edb84d9145b","contract":["WithExplicitBucketBoundaries configures explicit bucket boundaries on Float64HistogramConfig","WithExplicitBucketBoundaries configures explicit bucket boundaries on Int64HistogramConfig","WithExplicitBucketBoundaries preserves empty boundaries when no arguments provided","Float64Histogram and Int64Histogram instruments initialize with explicit bucket boundaries","Instruments created with WithExplicitBucketBoundaries record measurements successfully"],"goal":"verify go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","moduleSystem":"go.mod","os":"linux","osVersionBucket":"24","packageManager":"go","runtime":"go","runtimeVersion":"1.26","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0","symbols":["go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries"],"verifierAdapter":"golang@1"}

module example.com/otel-metric-boundaries

go 1.22

require (
	go.opentelemetry.io/otel v1.24.0
	go.opentelemetry.io/otel/metric v1.24.0
)

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 v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
github.com/go-logr/logr v1.4.1/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 v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
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 v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
go.opentelemetry.io/otel v1.24.0 h1:0LAOdjNmQeSTzGBzduGe/rU4tZhMwL5rWgtp9Ku5Jfo=
go.opentelemetry.io/otel v1.24.0/go.mod h1:W7b9Ozg4nkF5tWI5zsXkaKKDjdVjpD4oAt9Qi/MArHo=
go.opentelemetry.io/otel/metric v1.24.0 h1:6EhoGWWK28x1fbpA4tYTOWBkPefTDQnb8WSGXlc88kI=
go.opentelemetry.io/otel/metric v1.24.0/go.mod h1:VYhLe1rFfxuTXLgj4CBiyz+9WYBA8pNGJgDcSFRKBco=
go.opentelemetry.io/otel/trace v1.24.0 h1:CsKnnL4dUAr/0llH9FKuc698G04IrpWV0MQA/Y1YELI=
go.opentelemetry.io/otel/trace v1.24.0/go.mod h1:HPc3Xr/cOApsBI154IU0OI0HJexz+aw5uPdbs3UCjNU=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries"
  ]
}

package test

import (
	"context"
	"reflect"
	"testing"

	sample "example.com/otel-metric-boundaries"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

func TestWithExplicitBucketBoundariesContract(t *testing.T) {
	ctx := context.Background()

	// 1. WithExplicitBucketBoundaries configures explicit bucket boundaries on Float64HistogramConfig
	wantFloatBounds := []float64{0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0}
	floatCfg := metric.NewFloat64HistogramConfig(metric.WithExplicitBucketBoundaries(wantFloatBounds...))
	gotFloatBounds := floatCfg.ExplicitBucketBoundaries()
	if !reflect.DeepEqual(gotFloatBounds, wantFloatBounds) {
		t.Fatalf("Float64HistogramConfig boundaries mismatch: got %v, want %v", gotFloatBounds, wantFloatBounds)
	}

	// 2. WithExplicitBucketBoundaries configures explicit bucket boundaries on Int64HistogramConfig
	wantIntBounds := []float64{10, 50, 100, 500, 1000}
	intCfg := metric.NewInt64HistogramConfig(metric.WithExplicitBucketBoundaries(wantIntBounds...))
	gotIntBounds := intCfg.ExplicitBucketBoundaries()
	if !reflect.DeepEqual(gotIntBounds, wantIntBounds) {
		t.Fatalf("Int64HistogramConfig boundaries mismatch: got %v, want %v", gotIntBounds, wantIntBounds)
	}

	// 3. WithExplicitBucketBoundaries preserves empty boundaries when no arguments provided
	emptyCfg := metric.NewFloat64HistogramConfig(metric.WithExplicitBucketBoundaries())
	if got := emptyCfg.ExplicitBucketBoundaries(); len(got) != 0 {
		t.Fatalf("expected empty boundaries, got %v", got)
	}

	// 4. Float64Histogram and Int64Histogram instruments initialize with explicit bucket boundaries
	mp := noop.NewMeterProvider()
	instruments, err := sample.NewHistogramInstruments(mp, "example.com/test-boundaries", wantFloatBounds, wantIntBounds)
	if err != nil {
		t.Fatalf("failed to create histogram instruments: %v", err)
	}
	if instruments.Duration == nil || instruments.Payload == nil {
		t.Fatal("expected both Duration and Payload instruments to be non-nil")
	}

	// 5. Instruments created with WithExplicitBucketBoundaries record measurements successfully
	instruments.RecordObservations(
		ctx,
		0.125,
		1024,
		attribute.String("http.route", "/api/v1/items"),
		attribute.Int("http.response.status_code", 200),
	)
}