go.opentelemetry.io/otel v1.32.0: ErrorHandler

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 otel.ErrorHandler in pkg:golang/go.opentelemetry.io/otel@v1.32.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel@v1.32.0
Demonstrate these symbols/APIs:
  - otel.ErrorHandler
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:d39e79a6e139d8b4f8eb5b018097a94582550edc347b7fce94508b7ac20ee43f","contract":["otel.SetErrorHandler registers a custom ErrorHandler that receives errors passed to otel.Handle","otel.ErrorHandlerFunc adapts a function to satisfy the otel.ErrorHandler interface","otel.GetErrorHandler returns a non-nil ErrorHandler"],"goal":"verify otel.ErrorHandler in pkg:golang/go.opentelemetry.io/otel@v1.32.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel@v1.32.0"],"schemaVersion":1,"symbols":["otel.ErrorHandler"]},"contractCommand":["go","test","./..."],"environment":{"arch":"amd64","compiler":"go","compilerVersion":"1.26.6","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel@v1.32.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel@v1.32.0","symbols":["otel.ErrorHandler"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	github.com/go-logr/logr v1.4.2 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	go.opentelemetry.io/otel v1.32.0 // indirect
	go.opentelemetry.io/otel/metric v1.32.0 // indirect
	go.opentelemetry.io/otel/trace v1.32.0 // indirect
)

github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
github.com/go-logr/logr v1.4.2/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=
go.opentelemetry.io/otel v1.32.0 h1:WnBN+Xjcteh0zdk01SVqV55d/m62NJLJdIyb4y/WO5U=
go.opentelemetry.io/otel v1.32.0/go.mod h1:00DCVSB0RQcnzlwyTfqtxSm+DRr9hpYrHjNGiBHVQIg=
go.opentelemetry.io/otel/metric v1.32.0 h1:xV2umtmNcThh2/a/aCP+h64Xx5wsj8qqnkYZktzNa0M=
go.opentelemetry.io/otel/metric v1.32.0/go.mod h1:jH7CIbbK6SH2V2wE16W05BHCtIDzauciCRLoc/SyMv8=
go.opentelemetry.io/otel/trace v1.32.0 h1:WIC9mYrXf8TmY/EXuULKc8hR17vE+Hjv2cssQDe03fM=
go.opentelemetry.io/otel/trace v1.32.0/go.mod h1:+i4rkvCraA+tG6AzwloGaCtkx53Fa+L+V8e9a7YvhT8=

package sample

import (
	"sync"

	"go.opentelemetry.io/otel"
)

// RecordingHandler records handled errors in a thread-safe slice.
type RecordingHandler struct {
	mu     sync.Mutex
	errors []error
}

// Handle implements otel.ErrorHandler.
func (h *RecordingHandler) Handle(err error) {
	if err == nil {
		return
	}
	h.mu.Lock()
	defer h.mu.Unlock()
	h.errors = append(h.errors, err)
}

// Errors returns a copy of recorded errors.
func (h *RecordingHandler) Errors() []error {
	h.mu.Lock()
	defer h.mu.Unlock()
	res := make([]error, len(h.errors))
	copy(res, h.errors)
	return res
}

// Count returns the number of recorded errors.
func (h *RecordingHandler) Count() int {
	h.mu.Lock()
	defer h.mu.Unlock()
	return len(h.errors)
}

// Ensure RecordingHandler implements otel.ErrorHandler.
var _ otel.ErrorHandler = (*RecordingHandler)(nil)

// ConfigureErrorHandler sets the global OpenTelemetry error handler to the given otel.ErrorHandler.
func ConfigureErrorHandler(handler otel.ErrorHandler) {
	otel.SetErrorHandler(handler)
}

// TriggerError passes an error to the global OpenTelemetry error handling mechanism.
func TriggerError(err error) {
	otel.Handle(err)
}

{
  "schemaVersion": 1,
  "goal": "verify otel.ErrorHandler in pkg:golang/go.opentelemetry.io/otel@v1.32.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel@v1.32.0"
  ],
  "symbols": [
    "otel.ErrorHandler"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

package test

import (
	"errors"
	"testing"

	"sample"

	"go.opentelemetry.io/otel"
)

func TestErrorHandlerContract(t *testing.T) {
	t.Run("implements otel.ErrorHandler and receives handled errors", func(t *testing.T) {
		handler := &sample.RecordingHandler{}
		sample.ConfigureErrorHandler(handler)

		testErr := errors.New("simulated otel error")
		sample.TriggerError(testErr)

		if handler.Count() != 1 {
			t.Fatalf("expected 1 error, got %d", handler.Count())
		}
		recorded := handler.Errors()
		if len(recorded) != 1 || recorded[0].Error() != "simulated otel error" {
			t.Fatalf("unexpected error recorded: %v", recorded)
		}
	})

	t.Run("ErrorHandlerFunc implements otel.ErrorHandler", func(t *testing.T) {
		var captured error
		var fnHandler otel.ErrorHandler = otel.ErrorHandlerFunc(func(err error) {
			captured = err
		})

		customErr := errors.New("custom functional error")
		fnHandler.Handle(customErr)

		if captured != customErr {
			t.Fatalf("expected custom error to be captured, got %v", captured)
		}
	})

	t.Run("GetErrorHandler returns an otel.ErrorHandler instance", func(t *testing.T) {
		currentHandler := otel.GetErrorHandler()
		if currentHandler == nil {
			t.Fatal("expected non-nil ErrorHandler from otel.GetErrorHandler()")
		}
	})
}