go.opentelemetry.io/otel/sdk v1.42.0: tracetest.NewInMemoryExporter

# OpenTelemetry Go SDK InMemoryExporter Lifecycle and Verification

## Goal

Verify `go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter` in `pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0`.

## Verified Contract

1. **Synchronous Span Capture**:
   When wired via `sdktrace.WithSyncer(exporter)`, completed spans are captured immediately and accessible through `exporter.GetSpans()`. Child spans inherit the parent's `TraceID` and reference the parent's `SpanID`.

2. **In-Memory Reset**:
   `exporter.Reset()` immediately empties collected spans while keeping the exporter active and ready to record subsequent spans.

3. **Shutdown Cascading**:
   Invoking `TracerProvider.Shutdown(ctx)` cascades to all registered exporters, causing `tracetest.InMemoryExporter` to clear all accumulated spans from memory.

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/trace/tracetest.NewInMemoryExporter in pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter

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.

package contract_test

import (
	"context"
	"testing"

	"go.opentelemetry.io/otel/attribute"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	"go.opentelemetry.io/otel/sdk/trace/tracetest"
)

func TestInMemoryExporterLifecycleAndSpans(t *testing.T) {
	ctx := context.Background()

	// 1. Initialize NewInMemoryExporter and wire to TracerProvider
	exporter := tracetest.NewInMemoryExporter()
	tp := sdktrace.NewTracerProvider(
		sdktrace.WithSyncer(exporter),
	)

	tracer := tp.Tracer("contract-inmemory-test")

	// 2. Start and end root and child spans
	ctxRoot, rootSpan := tracer.Start(ctx, "root-operation")
	rootSpan.SetAttributes(attribute.String("component", "core"), attribute.Int("status.code", 200))

	_, childSpan := tracer.Start(ctxRoot, "child-operation")
	childSpan.SetAttributes(attribute.String("subsystem", "auth"))
	childSpan.End()

	rootSpan.End()

	// 3. Verify synchronous collection and span properties
	spans := exporter.GetSpans()
	if len(spans) != 2 {
		t.Fatalf("expected 2 spans in InMemoryExporter, got %d", len(spans))
	}

	// Child ended before root, so child is at index 0, root at index 1
	childStub := spans[0]
	rootStub := spans[1]

	if childStub.Name != "child-operation" {
		t.Errorf("expected child span name 'child-operation', got %q", childStub.Name)
	}
	if rootStub.Name != "root-operation" {
		t.Errorf("expected root span name 'root-operation', got %q", rootStub.Name)
	}

	// Child span must share the root span TraceID
	if childStub.SpanContext.TraceID() != rootStub.SpanContext.TraceID() {
		t.Errorf("expected child TraceID to match root TraceID: %s != %s",
			childStub.SpanContext.TraceID(), rootStub.SpanContext.TraceID())
	}

	// Child span Parent SpanID must equal root SpanID
	if childStub.Parent.SpanID() != rootStub.SpanContext.SpanID() {
		t.Errorf("expected child parent SpanID to match root SpanID: %s != %s",
			childStub.Parent.SpanID(), rootStub.SpanContext.SpanID())
	}

	// 4. Verify exporter.Reset() clears accumulated spans without shutting down
	exporter.Reset()
	if remaining := len(exporter.GetSpans()); remaining != 0 {
		t.Fatalf("expected exporter.Reset() to clear spans, got %d", remaining)
	}

	// 5. Subsequent spans can still be recorded after Reset()
	_, postResetSpan := tracer.Start(ctx, "post-reset-operation")
	postResetSpan.End()

	postResetSpans := exporter.GetSpans()
	if len(postResetSpans) != 1 || postResetSpans[0].Name != "post-reset-operation" {
		t.Fatalf("expected 1 span after reset, got %d", len(postResetSpans))
	}

	// 6. TracerProvider.Shutdown() flushes and cascades shutdown to InMemoryExporter
	if err := tp.Shutdown(ctx); err != nil {
		t.Fatalf("tp.Shutdown failed: %v", err)
	}

	// InMemoryExporter clears stored spans on shutdown
	if afterShutdown := len(exporter.GetSpans()); afterShutdown != 0 {
		t.Errorf("expected exporter to have 0 spans after shutdown, got %d", afterShutdown)
	}
}

{"case":{"caseId":"case:sha256:1aaec8e182d1fb4b56d5b4291ae0c509b171dbd163f1846c88ed6c5f981f6049","contract":["NewInMemoryExporter coupled with TracerProvider synchronously collects exported spans via GetSpans","Exported child spans correctly record root span TraceID and parent SpanID","exporter.Reset() clears accumulated spans from memory without terminating the exporter","TracerProvider.Shutdown() flushes and cascades shutdown to InMemoryExporter, resetting held spans"],"goal":"verify go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter in pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","executionContext":"go","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","runtime":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0","symbols":["go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	go.opentelemetry.io/otel v1.42.0
	go.opentelemetry.io/otel/sdk v1.42.0
)

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/metric v1.42.0 // indirect
	go.opentelemetry.io/otel/trace v1.42.0 // indirect
	golang.org/x/sys v0.41.0 // 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 v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
golang.org/x/sys v0.41.0/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=

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter in pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk@v1.42.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/sdk/trace/tracetest.NewInMemoryExporter"
  ]
}