github.com/go-logr/logr v1.3.0: Discard

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 github.com/go-logr/logr.Discard in pkg:golang/github.com/go-logr/logr@v1.3.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/go-logr/logr@v1.3.0
Demonstrate these symbols/APIs:
  - github.com/go-logr/logr.Discard

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:sha256:94ea6b015e5e21313ce69c46b02af7d77dbc8556e1a0cb824ae42e889600dd88","contract":["logr.Discard returns a Logger with nil LogSink and IsZero reporting true","logr.Discard instances always compare as equal to each other and zero Logger","logr.Discard disables all logging and verbosity levels via Enabled","logr.Discard methods Info and Error execute safely without panicking or side effects","logr.Discard context integration with logr.NewContext and logr.FromContextOrDiscard"],"goal":"verify github.com/go-logr/logr.Discard in pkg:golang/github.com/go-logr/logr@v1.3.0","kind":"HOW","packages":["pkg:golang/github.com/go-logr/logr@v1.3.0"],"schemaVersion":1,"symbols":["github.com/go-logr/logr.Discard"]},"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/github.com/go-logr/logr@v1.3.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/go-logr/logr@v1.3.0","symbols":["github.com/go-logr/logr.Discard"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.22

require github.com/go-logr/logr v1.3.0

github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=
github.com/go-logr/logr v1.3.0/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=

package main

import (
	"context"
	"errors"
	"fmt"

	"github.com/go-logr/logr"
)

// Service demonstrates optional logging using logr.Discard as a safe default no-op logger.
type Service struct {
	logger logr.Logger
}

// NewService constructs a Service, defaulting to logr.Discard when no logger is supplied.
func NewService(logger *logr.Logger) *Service {
	if logger == nil {
		return &Service{logger: logr.Discard()}
	}
	return &Service{logger: *logger}
}

// DoWork executes a task while safely emitting logs through the configured logger.
func (s *Service) DoWork(ctx context.Context, item string) error {
	subLogger := s.logger.WithName("worker").WithValues("item", item)
	subLogger.Info("processing item")
	if item == "" {
		err := errors.New("empty item")
		subLogger.Error(err, "item processing failed")
		return err
	}
	subLogger.Info("item processed successfully")
	return nil
}

func main() {
	// Initialize service with a Discard logger
	discardLogger := logr.Discard()
	svc := NewService(&discardLogger)

	ctx := context.Background()
	_ = svc.DoWork(ctx, "sample-task")

	fmt.Println("Discard logger executed silently without errors")
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/go-logr/logr.Discard in pkg:golang/github.com/go-logr/logr@v1.3.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/go-logr/logr@v1.3.0"
  ],
  "symbols": [
    "github.com/go-logr/logr.Discard"
  ]
}

package main

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

	"github.com/go-logr/logr"
)

func main() {
	// Contract 1: logr.Discard returns a Logger with nil LogSink and IsZero reporting true
	{
		l := logr.Discard()
		if l.GetSink() != nil {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard().GetSink() should be nil\n")
			os.Exit(1)
		}
		if !l.IsZero() {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard().IsZero() should be true\n")
			os.Exit(1)
		}
	}

	// Contract 2: logr.Discard instances always compare as equal to each other and zero Logger
	{
		d1 := logr.Discard()
		d2 := logr.Discard()
		zero := logr.Logger{}
		if d1 != d2 {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard() instances must compare as equal\n")
			os.Exit(1)
		}
		if d1 != zero {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard() must equal zero Logger{}\n")
			os.Exit(1)
		}
	}

	// Contract 3: logr.Discard disables all logging and verbosity levels via Enabled
	{
		l := logr.Discard()
		if l.Enabled() {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard().Enabled() must be false\n")
			os.Exit(1)
		}
		if l.V(0).Enabled() || l.V(1).Enabled() || l.V(10).Enabled() {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard().V().Enabled() must be false for any level\n")
			os.Exit(1)
		}
		if l.GetV() != 0 || l.V(5).GetV() != 0 {
			fmt.Fprintf(os.Stderr, "FAIL: logr.Discard().GetV() must remain 0\n")
			os.Exit(1)
		}
	}

	// Contract 4: logr.Discard methods Info and Error execute safely without panicking or side effects
	{
		l := logr.Discard()
		// Calling Info and Error with arbitrary keys and values must succeed without panic
		l.Info("testing discard info message", "key1", "val1", "count", 42)
		testErr := errors.New("synthetic test error")
		l.Error(testErr, "testing discard error message", "component", "contract-test")

		// Derived loggers (WithName, WithValues, WithCallDepth) return unchanged discard loggers
		derived := l.WithName("sub").WithValues("k", "v").WithCallDepth(2)
		if derived != l {
			fmt.Fprintf(os.Stderr, "FAIL: derived discard loggers must equal base discard logger\n")
			os.Exit(1)
		}
		derived.Info("derived info")
		derived.Error(errors.New("sub error"), "derived error")
	}

	// Contract 5: logr.Discard context integration with logr.NewContext and logr.FromContextOrDiscard
	{
		l := logr.Discard()
		ctx := logr.NewContext(context.Background(), l)
		fromCtx, err := logr.FromContext(ctx)
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: logr.FromContext failed: %v\n", err)
			os.Exit(1)
		}
		if fromCtx != l {
			fmt.Fprintf(os.Stderr, "FAIL: retrieved logger must equal discard logger\n")
			os.Exit(1)
		}

		emptyCtx := context.Background()
		discardFromEmpty := logr.FromContextOrDiscard(emptyCtx)
		if discardFromEmpty != l {
			fmt.Fprintf(os.Stderr, "FAIL: logr.FromContextOrDiscard on empty context must equal logr.Discard()\n")
			os.Exit(1)
		}
	}

	fmt.Println("PASS: github.com/go-logr/logr.Discard contracts verified successfully")
}