go.opentelemetry.io/otel/sdk/metric v1.39.0: metricdata.Temporality

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/metricdata.Temporality 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/metricdata.Temporality

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:e174f8bdb8f568f13cb15a24d9380741623fef27982b4241a1d1c00e3a60aa69","contract":["metricdata.Temporality represents the aggregation window and includes CumulativeTemporality and DeltaTemporality constants.","Temporality.String() returns canonical string names for CumulativeTemporality and DeltaTemporality.","Temporality.MarshalText() encodes the Temporality into UTF-8 text matching String().","metric.TemporalitySelector maps InstrumentKind values to metricdata.Temporality.","metric.ManualReader with a custom TemporalitySelector produces metricdata aggregations carrying the selected Temporality."],"goal":"verify go.opentelemetry.io/otel/sdk/metric/metricdata.Temporality 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/metricdata.Temporality"]},"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/metricdata.Temporality"],"verifierAdapter":"golang@1"}

module example.com/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 main

import (
	"context"
	"fmt"

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

func main() {
	// Temporality defines whether an aggregation is reported as cumulative or delta.
	var cumulative metricdata.Temporality = metricdata.CumulativeTemporality
	var delta metricdata.Temporality = metricdata.DeltaTemporality

	fmt.Printf("Cumulative Temporality: %s\n", cumulative)
	fmt.Printf("Delta Temporality: %s\n", delta)

	// Configure a TemporalitySelector for metric readers
	deltaSelector := func(metric.InstrumentKind) metricdata.Temporality {
		return metricdata.DeltaTemporality
	}

	reader := metric.NewManualReader(metric.WithTemporalitySelector(deltaSelector))
	meterProvider := metric.NewMeterProvider(metric.WithReader(reader))
	defer func() { _ = meterProvider.Shutdown(context.Background()) }()

	meter := meterProvider.Meter("example.com/temporality-demo")
	counter, err := meter.Int64Counter("events_total")
	if err != nil {
		panic(err)
	}

	ctx := context.Background()
	counter.Add(ctx, 10)

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

	for _, sm := range rm.ScopeMetrics {
		for _, m := range sm.Metrics {
			if sumData, ok := m.Data.(metricdata.Sum[int64]); ok {
				fmt.Printf("Metric %s temporality: %s\n", m.Name, sumData.Temporality)
			}
		}
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/metric/metricdata.Temporality 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/metricdata.Temporality"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

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

func main() {
	if err := runContractTests(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All contract assertions passed.")
}

func runContractTests() error {
	// 1. metricdata.Temporality represents the aggregation window and includes CumulativeTemporality and DeltaTemporality constants.
	var t metricdata.Temporality
	if t == metricdata.CumulativeTemporality || t == metricdata.DeltaTemporality {
		return fmt.Errorf("default Temporality should be zero-value, got %v", t)
	}
	if metricdata.CumulativeTemporality == metricdata.DeltaTemporality {
		return fmt.Errorf("expected CumulativeTemporality != DeltaTemporality")
	}

	// 2. Temporality.String() returns canonical string names for CumulativeTemporality and DeltaTemporality.
	if s := metricdata.CumulativeTemporality.String(); s != "CumulativeTemporality" {
		return fmt.Errorf("expected CumulativeTemporality.String() == 'CumulativeTemporality', got %q", s)
	}
	if s := metricdata.DeltaTemporality.String(); s != "DeltaTemporality" {
		return fmt.Errorf("expected DeltaTemporality.String() == 'DeltaTemporality', got %q", s)
	}
	if s := metricdata.Temporality(99).String(); s != "Temporality(99)" {
		return fmt.Errorf("expected unknown Temporality.String() == 'Temporality(99)', got %q", s)
	}

	// 3. Temporality.MarshalText() encodes the Temporality into UTF-8 text matching String().
	cumText, err := metricdata.CumulativeTemporality.MarshalText()
	if err != nil {
		return fmt.Errorf("failed to marshal CumulativeTemporality: %w", err)
	}
	if string(cumText) != "CumulativeTemporality" {
		return fmt.Errorf("expected MarshalText 'CumulativeTemporality', got %q", string(cumText))
	}
	deltaText, err := metricdata.DeltaTemporality.MarshalText()
	if err != nil {
		return fmt.Errorf("failed to marshal DeltaTemporality: %w", err)
	}
	if string(deltaText) != "DeltaTemporality" {
		return fmt.Errorf("expected MarshalText 'DeltaTemporality', got %q", string(deltaText))
	}

	// 4. metric.TemporalitySelector maps InstrumentKind values to metricdata.Temporality.
	customSelector := func(kind metric.InstrumentKind) metricdata.Temporality {
		if kind == metric.InstrumentKindCounter {
			return metricdata.DeltaTemporality
		}
		return metricdata.CumulativeTemporality
	}
	var selector metric.TemporalitySelector = customSelector
	if got := selector(metric.InstrumentKindCounter); got != metricdata.DeltaTemporality {
		return fmt.Errorf("expected DeltaTemporality for Counter, got %v", got)
	}
	if got := selector(metric.InstrumentKindGauge); got != metricdata.CumulativeTemporality {
		return fmt.Errorf("expected CumulativeTemporality for Gauge, got %v", got)
	}
	if got := metric.DefaultTemporalitySelector(metric.InstrumentKindCounter); got != metricdata.CumulativeTemporality {
		return fmt.Errorf("expected DefaultTemporalitySelector to return CumulativeTemporality, got %v", got)
	}

	// 5. metric.ManualReader with a custom TemporalitySelector produces metricdata aggregations carrying the selected Temporality.
	reader := metric.NewManualReader(metric.WithTemporalitySelector(customSelector))
	mp := metric.NewMeterProvider(metric.WithReader(reader))
	defer func() { _ = mp.Shutdown(context.Background()) }()

	meter := mp.Meter("example.com/test-meter")
	counter, err := meter.Int64Counter("items_processed")
	if err != nil {
		return fmt.Errorf("failed to create counter: %w", err)
	}

	ctx := context.Background()
	counter.Add(ctx, 42)

	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err != nil {
		return fmt.Errorf("failed to collect metrics: %w", err)
	}

	if len(rm.ScopeMetrics) == 0 || len(rm.ScopeMetrics[0].Metrics) == 0 {
		return fmt.Errorf("expected at least one metric to be collected")
	}

	sumData, ok := rm.ScopeMetrics[0].Metrics[0].Data.(metricdata.Sum[int64])
	if !ok {
		return fmt.Errorf("expected metric data type Sum[int64], got %T", rm.ScopeMetrics[0].Metrics[0].Data)
	}

	if sumData.Temporality != metricdata.DeltaTemporality {
		return fmt.Errorf("expected sum temporality to be DeltaTemporality, got %v", sumData.Temporality)
	}
	if len(sumData.DataPoints) != 1 || sumData.DataPoints[0].Value != 42 {
		return fmt.Errorf("expected data point value 42, got %v", sumData.DataPoints)
	}

	return nil
}