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

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.Stream 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.Stream

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:sha256:0f824af3f7ec05fd1fbf9a61cb4e54fd05acd8510fda49fa9b8ba3f7f856108d","contract":["Stream struct defines properties for metric instrument data streams including Name, Description, and Unit","Stream configured via NewView replaces instrument name, description, and unit","Stream configured with AggregationExplicitBucketHistogram customizes histogram bucket boundaries","Stream configured with AttributeFilter filters measurement attributes","Stream configured with AggregationDrop suppresses instrument data collection","MeterProvider records and collects metrics transformed by configured Stream views"],"goal":"verify go.opentelemetry.io/otel/sdk/metric.Stream 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.Stream"]},"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@v1.44.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.44.0","symbols":["go.opentelemetry.io/otel/sdk/metric.Stream"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.25.0

require (
	go.opentelemetry.io/otel v1.44.0
	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/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=

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

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	sdkmetric "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 tests passed successfully.")
}

func runContractTests() error {
	// 1. Stream struct defines properties for metric instrument data streams including Name, Description, and Unit
	{
		s := sdkmetric.Stream{
			Name:        "custom.latency",
			Description: "Custom latency stream",
			Unit:        "ms",
		}
		if s.Name != "custom.latency" || s.Description != "Custom latency stream" || s.Unit != "ms" {
			return fmt.Errorf("test 1 (Stream struct properties) failed: got Name=%q, Desc=%q, Unit=%q", s.Name, s.Description, s.Unit)
		}
	}

	// 2. Stream configured via NewView replaces instrument name, description, and unit
	{
		view := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "http.request.duration"},
			sdkmetric.Stream{
				Name:        "http.server.duration",
				Description: "Server-side request duration",
				Unit:        "s",
			},
		)
		stream, matched := view(sdkmetric.Instrument{
			Name:        "http.request.duration",
			Description: "Original duration",
			Unit:        "ms",
		})
		if !matched {
			return fmt.Errorf("test 2 (NewView match) failed: expected view to match instrument")
		}
		if stream.Name != "http.server.duration" || stream.Description != "Server-side request duration" || stream.Unit != "s" {
			return fmt.Errorf("test 2 (NewView replace) failed: got Name=%q, Desc=%q, Unit=%q", stream.Name, stream.Description, stream.Unit)
		}
	}

	// 3. Stream configured with AggregationExplicitBucketHistogram customizes histogram bucket boundaries
	{
		boundaries := []float64{0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0}
		view := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "rpc.server.duration"},
			sdkmetric.Stream{
				Aggregation: sdkmetric.AggregationExplicitBucketHistogram{
					Boundaries: boundaries,
				},
			},
		)
		stream, matched := view(sdkmetric.Instrument{Name: "rpc.server.duration"})
		if !matched {
			return fmt.Errorf("test 3 (aggregation match) failed: expected view to match instrument")
		}
		agg, ok := stream.Aggregation.(sdkmetric.AggregationExplicitBucketHistogram)
		if !ok {
			return fmt.Errorf("test 3 (aggregation type) failed: expected AggregationExplicitBucketHistogram, got %T", stream.Aggregation)
		}
		if len(agg.Boundaries) != len(boundaries) {
			return fmt.Errorf("test 3 (boundaries length) failed: got %d, want %d", len(agg.Boundaries), len(boundaries))
		}
		for i, b := range boundaries {
			if agg.Boundaries[i] != b {
				return fmt.Errorf("test 3 (boundary value at %d) failed: got %f, want %f", i, agg.Boundaries[i], b)
			}
		}
	}

	// 4. Stream configured with AttributeFilter filters measurement attributes
	{
		filter := attribute.NewAllowKeysFilter("http.method", "http.status_code")
		view := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "http.requests"},
			sdkmetric.Stream{
				AttributeFilter: filter,
			},
		)
		stream, matched := view(sdkmetric.Instrument{Name: "http.requests"})
		if !matched {
			return fmt.Errorf("test 4 (attribute filter match) failed: expected view to match instrument")
		}
		if stream.AttributeFilter == nil {
			return fmt.Errorf("test 4 (nil AttributeFilter) failed: expected non-nil filter")
		}
		if !stream.AttributeFilter(attribute.String("http.method", "GET")) {
			return fmt.Errorf("test 4 (allowed attribute) failed: expected http.method to be allowed")
		}
		if stream.AttributeFilter(attribute.String("user.id", "secret123")) {
			return fmt.Errorf("test 4 (denied attribute) failed: expected user.id to be filtered out")
		}
	}

	// 5. Stream configured with AggregationDrop suppresses instrument data collection
	{
		dropView := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "noisy.metric"},
			sdkmetric.Stream{
				Aggregation: sdkmetric.AggregationDrop{},
			},
		)
		stream, matched := dropView(sdkmetric.Instrument{Name: "noisy.metric"})
		if !matched {
			return fmt.Errorf("test 5 (drop view match) failed: expected view to match instrument")
		}
		if _, ok := stream.Aggregation.(sdkmetric.AggregationDrop); !ok {
			return fmt.Errorf("test 5 (drop aggregation type) failed: expected AggregationDrop, got %T", stream.Aggregation)
		}
	}

	// 6. MeterProvider records and collects metrics transformed by configured Stream views
	{
		ctx := context.Background()
		reader := sdkmetric.NewManualReader()

		streamView := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "raw.requests"},
			sdkmetric.Stream{
				Name:            "processed.requests",
				Description:     "Processed request count",
				Unit:            "1",
				AttributeFilter: attribute.NewAllowKeysFilter("env", "endpoint"),
			},
		)
		dropView := sdkmetric.NewView(
			sdkmetric.Instrument{Name: "unwanted.debug"},
			sdkmetric.Stream{
				Aggregation: sdkmetric.AggregationDrop{},
			},
		)

		mp := sdkmetric.NewMeterProvider(
			sdkmetric.WithReader(reader),
			sdkmetric.WithView(streamView),
			sdkmetric.WithView(dropView),
		)
		defer mp.Shutdown(ctx)

		meter := mp.Meter("contract-meter")
		counter, err := meter.Int64Counter("raw.requests")
		if err != nil {
			return fmt.Errorf("test 6 (create counter) failed: %w", err)
		}
		counter.Add(ctx, 5, metric.WithAttributes(
			attribute.String("env", "prod"),
			attribute.String("endpoint", "/api/v1"),
			attribute.String("auth_token", "super_secret"),
		))

		dropCounter, err := meter.Int64Counter("unwanted.debug")
		if err != nil {
			return fmt.Errorf("test 6 (create drop counter) failed: %w", err)
		}
		dropCounter.Add(ctx, 100)

		var rm metricdata.ResourceMetrics
		if err := reader.Collect(ctx, &rm); err != nil {
			return fmt.Errorf("test 6 (collect metrics) failed: %w", err)
		}

		if len(rm.ScopeMetrics) == 0 {
			return fmt.Errorf("test 6 (empty ScopeMetrics) failed: expected scope metrics")
		}

		var foundProcessed bool
		for _, sm := range rm.ScopeMetrics {
			for _, m := range sm.Metrics {
				if m.Name == "unwanted.debug" {
					return fmt.Errorf("test 6 (drop check) failed: unwanted.debug was collected despite AggregationDrop")
				}
				if m.Name == "processed.requests" {
					foundProcessed = true
					if m.Description != "Processed request count" {
						return fmt.Errorf("test 6 (metric description) failed: got %q, want %q", m.Description, "Processed request count")
					}
					if m.Unit != "1" {
						return fmt.Errorf("test 6 (metric unit) failed: got %q, want %q", m.Unit, "1")
					}

					sumData, ok := m.Data.(metricdata.Sum[int64])
					if !ok {
						return fmt.Errorf("test 6 (sum data type) failed: expected Sum[int64], got %T", m.Data)
					}
					if len(sumData.DataPoints) == 0 {
						return fmt.Errorf("test 6 (data points empty) failed: expected at least 1 data point")
					}
					dp := sumData.DataPoints[0]
					if dp.Value != 5 {
						return fmt.Errorf("test 6 (data point value) failed: got %d, want 5", dp.Value)
					}
					if !dp.Attributes.HasValue(attribute.Key("env")) {
						return fmt.Errorf("test 6 (attribute filter) failed: missing allowed attribute 'env'")
					}
					if !dp.Attributes.HasValue(attribute.Key("endpoint")) {
						return fmt.Errorf("test 6 (attribute filter) failed: missing allowed attribute 'endpoint'")
					}
					if dp.Attributes.HasValue(attribute.Key("auth_token")) {
						return fmt.Errorf("test 6 (attribute filter) failed: attribute 'auth_token' was not filtered out")
					}
				}
			}
		}

		if !foundProcessed {
			return fmt.Errorf("test 6 (stream rename) failed: processed.requests metric was not found in collected metrics")
		}
	}

	return nil
}