go.opentelemetry.io/otel/sdk/metric v1.37.0: ErrReaderShutdown

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.ErrReaderShutdown in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown

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:sha256:150f10c2cf2fa07ed6ac8b8410888f344be0ae81ba74d5d23ab16e29edb88e3b","contract":["metric.ErrReaderShutdown is a non-nil sentinel error with error string 'reader is shutdown'.","ManualReader.Shutdown succeeds on the first call with nil error.","ManualReader.Shutdown returns ErrReaderShutdown on subsequent calls, verifiable with errors.Is.","ManualReader.Collect returns ErrReaderShutdown when invoked after the reader is shutdown.","ErrReaderShutdown wrapped with fmt.Errorf still matches via errors.Is."],"goal":"verify go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown"]},"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@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0","symbols":["go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require go.opentelemetry.io/otel/sdk/metric v1.37.0

require (
	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 v1.1.0 // indirect
	go.opentelemetry.io/otel v1.37.0 // indirect
	go.opentelemetry.io/otel/metric v1.37.0 // indirect
	go.opentelemetry.io/otel/sdk v1.37.0 // indirect
	go.opentelemetry.io/otel/trace v1.37.0 // indirect
	golang.org/x/sys v0.33.0 // indirect
)

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 v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
go.opentelemetry.io/otel/metric v1.37.0 h1:mvwbQS5m0tbmqML4NqK+e3aDiO02vsf/WgbsdpcPoZE=
go.opentelemetry.io/otel/metric v1.37.0/go.mod h1:04wGrZurHYKOc+RKeye86GwKiTb9FKm1WHtO+4EVr2E=
go.opentelemetry.io/otel/sdk v1.37.0 h1:ItB0QUqnjesGRvNcmAcU0LyvkVyGJ2xftD29bWdDvKI=
go.opentelemetry.io/otel/sdk v1.37.0/go.mod h1:VredYzxUvuo2q3WRcDnKDjbdvmO0sCzOvVAiY+yUkAg=
go.opentelemetry.io/otel/sdk/metric v1.37.0 h1:90lI228XrB9jCMuSdA0673aubgRobVZFhbjxHHspCPc=
go.opentelemetry.io/otel/sdk/metric v1.37.0/go.mod h1:cNen4ZWfiD37l5NhS+Keb5RXVWZWpRE+9WyVCpbo5ps=
go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mxVK7z4=
go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
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"
	"errors"
	"fmt"

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

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

	// Create a new ManualReader
	reader := metric.NewManualReader()

	// First shutdown succeeds
	if err := reader.Shutdown(ctx); err != nil {
		fmt.Printf("Unexpected error on first shutdown: %v\n", err)
		return
	}

	// Second shutdown returns ErrReaderShutdown
	if err := reader.Shutdown(ctx); errors.Is(err, metric.ErrReaderShutdown) {
		fmt.Printf("Subsequent Shutdown correctly returned ErrReaderShutdown: %v\n", err)
	}

	// Collect after shutdown returns ErrReaderShutdown
	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); errors.Is(err, metric.ErrReaderShutdown) {
		fmt.Printf("Collect after Shutdown correctly returned ErrReaderShutdown: %v\n", err)
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown in pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk/metric@v1.37.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/sdk/metric.ErrReaderShutdown"
  ]
}

package main

import (
	"context"
	"errors"
	"fmt"
	"os"

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

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

	// Assertion 1: metric.ErrReaderShutdown is a non-nil sentinel error with error string "reader is shutdown".
	if metric.ErrReaderShutdown == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected metric.ErrReaderShutdown to be non-nil\n")
		os.Exit(1)
	}
	if got := metric.ErrReaderShutdown.Error(); got != "reader is shutdown" {
		fmt.Fprintf(os.Stderr, "FAIL: expected error message 'reader is shutdown', got %q\n", got)
		os.Exit(1)
	}

	// Assertion 2: ManualReader.Shutdown succeeds on the first call with nil error.
	reader := metric.NewManualReader()
	if err := reader.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected first reader.Shutdown to succeed, got %v\n", err)
		os.Exit(1)
	}

	// Assertion 3: ManualReader.Shutdown returns ErrReaderShutdown on subsequent calls, verifiable with errors.Is.
	if err := reader.Shutdown(ctx); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error on second reader.Shutdown, got nil\n")
		os.Exit(1)
	} else if !errors.Is(err, metric.ErrReaderShutdown) {
		fmt.Fprintf(os.Stderr, "FAIL: expected errors.Is(err, metric.ErrReaderShutdown) to be true, got %v\n", err)
		os.Exit(1)
	}

	// Assertion 4: ManualReader.Collect returns ErrReaderShutdown when invoked after the reader is shutdown.
	var rm metricdata.ResourceMetrics
	if err := reader.Collect(ctx, &rm); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error on Collect after shutdown, got nil\n")
		os.Exit(1)
	} else if !errors.Is(err, metric.ErrReaderShutdown) {
		fmt.Fprintf(os.Stderr, "FAIL: expected errors.Is(err, metric.ErrReaderShutdown) on Collect, got %v\n", err)
		os.Exit(1)
	}

	// Assertion 5: ErrReaderShutdown wrapped with fmt.Errorf still matches via errors.Is.
	wrappedErr := fmt.Errorf("operation failed: %w", metric.ErrReaderShutdown)
	if !errors.Is(wrappedErr, metric.ErrReaderShutdown) {
		fmt.Fprintf(os.Stderr, "FAIL: expected errors.Is to match wrapped ErrReaderShutdown\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all metric.ErrReaderShutdown contract assertions passed.")
}