google.golang.org/grpc v1.75.1: ErrServerStopped

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 google.golang.org/grpc.ErrServerStopped in pkg:golang/google.golang.org/grpc@v1.75.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/google.golang.org/grpc@v1.75.1
Demonstrate these symbols/APIs:
  - google.golang.org/grpc.ErrServerStopped

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:sha256:06ca65eea2b401ed8437653afd49044ba7f164e03788b0141ccd54ef9741a99c","contract":["grpc.ErrServerStopped is a non-nil sentinel error with message \"grpc: the server has been stopped\".","server.Serve returns grpc.ErrServerStopped when called on a server stopped via Stop.","server.Serve returns grpc.ErrServerStopped when called on a server stopped via GracefulStop.","server.Serve closes the provided net.Listener when returning grpc.ErrServerStopped.","errors.Is matches grpc.ErrServerStopped against errors returned by Serve on a stopped server."],"goal":"verify google.golang.org/grpc.ErrServerStopped in pkg:golang/google.golang.org/grpc@v1.75.1","kind":"HOW","packages":["pkg:golang/google.golang.org/grpc@v1.75.1"],"schemaVersion":1,"symbols":["google.golang.org/grpc.ErrServerStopped"]},"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/google.golang.org/grpc@v1.75.1"],"schemaVersion":1,"subject":"pkg:golang/google.golang.org/grpc@v1.75.1","symbols":["google.golang.org/grpc.ErrServerStopped"],"verifierAdapter":"golang@1"}

module example.com/grpc-errserverstopped

go 1.25.0

require google.golang.org/grpc v1.75.1

require (
	golang.org/x/net v0.41.0 // indirect
	golang.org/x/sys v0.33.0 // indirect
	golang.org/x/text v0.26.0 // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 // indirect
	google.golang.org/protobuf v1.36.6 // indirect
)

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/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
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=
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/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 h1:pFyd6EwwL2TqFf8emdthzeX+gZE1ElRq3iM8pui4KBY=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
google.golang.org/grpc v1.75.1 h1:/ODCNEuf9VghjgO3rqLcfg8fiOP0nSluljWFlDxELLI=
google.golang.org/grpc v1.75.1/go.mod h1:JtPAzKiq4v1xcAB2hydNlWI2RnF85XXcV0mhKXr2ecQ=
google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY=
google.golang.org/protobuf v1.36.6/go.mod h1:jduwjTPXsFjZGTmRluh+L6NjiWu7pchiJ2/5YcXBHnY=

package main

import (
	"errors"
	"fmt"
	"net"

	"google.golang.org/grpc"
)

func main() {
	lis, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		fmt.Printf("failed to listen: %v\n", err)
		return
	}

	server := grpc.NewServer()
	server.Stop()

	err = server.Serve(lis)
	if errors.Is(err, grpc.ErrServerStopped) {
		fmt.Printf("server returned expected error: %v\n", err)
	} else {
		fmt.Printf("unexpected error: %v\n", err)
	}
}

{
  "schemaVersion": 1,
  "goal": "verify google.golang.org/grpc.ErrServerStopped in pkg:golang/google.golang.org/grpc@v1.75.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/google.golang.org/grpc@v1.75.1"
  ],
  "symbols": [
    "google.golang.org/grpc.ErrServerStopped"
  ]
}

package main

import (
	"errors"
	"fmt"
	"net"
	"os"

	"google.golang.org/grpc"
)

func assert(cond bool, msg string, args ...any) {
	if !cond {
		fmt.Fprintf(os.Stderr, "CONTRACT ASSERTION FAILED: "+msg+"\n", args...)
		os.Exit(1)
	}
}

func main() {
	// Assertion 1: grpc.ErrServerStopped is a non-nil sentinel error with message "grpc: the server has been stopped".
	{
		assert(grpc.ErrServerStopped != nil, "grpc.ErrServerStopped is nil")
		assert(grpc.ErrServerStopped.Error() == "grpc: the server has been stopped",
			"unexpected error message: %q", grpc.ErrServerStopped.Error())
	}

	// Assertion 2: server.Serve returns grpc.ErrServerStopped when called on a server stopped via Stop.
	{
		lis, err := net.Listen("tcp", "127.0.0.1:0")
		assert(err == nil, "net.Listen failed: %v", err)

		server := grpc.NewServer()
		server.Stop()

		err = server.Serve(lis)
		assert(err == grpc.ErrServerStopped, "expected grpc.ErrServerStopped, got: %v", err)
	}

	// Assertion 3: server.Serve returns grpc.ErrServerStopped when called on a server stopped via GracefulStop.
	{
		lis, err := net.Listen("tcp", "127.0.0.1:0")
		assert(err == nil, "net.Listen failed: %v", err)

		server := grpc.NewServer()
		server.GracefulStop()

		err = server.Serve(lis)
		assert(err == grpc.ErrServerStopped, "expected grpc.ErrServerStopped after GracefulStop, got: %v", err)
	}

	// Assertion 4: server.Serve closes the provided net.Listener when returning grpc.ErrServerStopped.
	{
		lis, err := net.Listen("tcp", "127.0.0.1:0")
		assert(err == nil, "net.Listen failed: %v", err)

		server := grpc.NewServer()
		server.Stop()

		err = server.Serve(lis)
		assert(err == grpc.ErrServerStopped, "expected grpc.ErrServerStopped, got: %v", err)

		closeErr := lis.Close()
		assert(closeErr != nil && errors.Is(closeErr, net.ErrClosed),
			"expected listener to already be closed, got: %v", closeErr)
	}

	// Assertion 5: errors.Is matches grpc.ErrServerStopped against errors returned by Serve on a stopped server.
	{
		lis, err := net.Listen("tcp", "127.0.0.1:0")
		assert(err == nil, "net.Listen failed: %v", err)

		server := grpc.NewServer()
		server.Stop()

		err = server.Serve(lis)
		assert(errors.Is(err, grpc.ErrServerStopped), "errors.Is(err, grpc.ErrServerStopped) should be true")
		assert(!errors.Is(errors.New("other error"), grpc.ErrServerStopped), "errors.Is should not match unrelated error")
	}

	fmt.Println("All contract assertions passed successfully.")
}