github.com/sirupsen/logrus v1.4.2: Entry

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/sirupsen/logrus.Entry in pkg:golang/github.com/sirupsen/logrus@v1.4.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/sirupsen/logrus@v1.4.2
Demonstrate these symbols/APIs:
  - github.com/sirupsen/logrus.Entry

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:b74561f97eb6ee9adc183bf4b02b575dadc7e634ca64acf4c7c30c8faafdf0ea","contract":["logrus.NewEntry associates the entry with the provided logger and initializes an empty data map","Entry.WithField returns an entry copy containing the new key-value pair while leaving the parent unchanged","Entry.WithFields returns an entry copy containing multiple fields while leaving the parent unchanged","Entry.WithError sets the error under the standard logrus.ErrorKey field in the entry copy","Entry.WithTime sets the timestamp on the returned entry copy","Entry.String serializes the entry using the logger formatter and contains the message and fields"],"goal":"verify github.com/sirupsen/logrus.Entry in pkg:golang/github.com/sirupsen/logrus@v1.4.2","kind":"HOW","packages":["pkg:golang/github.com/sirupsen/logrus@v1.4.2"],"schemaVersion":1,"symbols":["github.com/sirupsen/logrus.Entry"]},"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/sirupsen/logrus@v1.4.2"],"schemaVersion":1,"subject":"pkg:golang/github.com/sirupsen/logrus@v1.4.2","symbols":["github.com/sirupsen/logrus.Entry"],"verifierAdapter":"golang@1"}

module sample

go 1.22

require github.com/sirupsen/logrus v1.4.2

require (
	github.com/konsorten/go-windows-terminal-sequences v1.0.1 // indirect
	golang.org/x/sys v0.0.0-20190422165155-953cdadca894 // 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/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
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/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

package main

import (
	"bytes"
	"fmt"
	"time"

	"github.com/sirupsen/logrus"
)

func main() {
	buf := new(bytes.Buffer)
	logger := logrus.New()
	logger.SetOutput(buf)
	logger.SetFormatter(&logrus.TextFormatter{
		DisableColors: true,
	})

	// Create an Entry from the logger
	entry := logrus.NewEntry(logger)

	// Chain fields and metadata onto the entry
	fixedTime := time.Date(2026, time.September, 17, 12, 0, 0, 0, time.UTC)
	childEntry := entry.
		WithField("app", "demo").
		WithFields(logrus.Fields{
			"env":     "production",
			"version": "1.0.0",
		}).
		WithTime(fixedTime)

	// Log using the Entry
	childEntry.Info("demonstrating logrus.Entry fields and logging")

	// Print formatted output from the logger buffer
	fmt.Print(buf.String())
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/sirupsen/logrus.Entry in pkg:golang/github.com/sirupsen/logrus@v1.4.2",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/sirupsen/logrus@v1.4.2"
  ],
  "symbols": [
    "github.com/sirupsen/logrus.Entry"
  ]
}

package main

import (
	"bytes"
	"errors"
	"fmt"
	"os"
	"strings"
	"time"

	"github.com/sirupsen/logrus"
)

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract verification failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All logrus.Entry contract assertions passed successfully.")
}

func runContract() error {
	logger := logrus.New()
	logger.SetOutput(new(bytes.Buffer))

	// Assertion 1: logrus.NewEntry associates the entry with the provided logger and initializes an empty data map
	entry := logrus.NewEntry(logger)
	if entry.Logger != logger {
		return fmt.Errorf("expected entry.Logger to match provided logger, got %v", entry.Logger)
	}
	if entry.Data == nil {
		return fmt.Errorf("expected entry.Data map to be initialized, got nil")
	}
	if len(entry.Data) != 0 {
		return fmt.Errorf("expected entry.Data to be empty initially, got %v", entry.Data)
	}

	// Assertion 2: Entry.WithField returns an entry copy containing the new key-value pair while leaving the parent unchanged
	childField := entry.WithField("cluster", "prod-east")
	if childField.Data["cluster"] != "prod-east" {
		return fmt.Errorf("expected childField to contain cluster='prod-east', got %v", childField.Data["cluster"])
	}
	if _, exists := entry.Data["cluster"]; exists {
		return fmt.Errorf("expected parent entry to remain unchanged after WithField")
	}

	// Assertion 3: Entry.WithFields returns an entry copy containing multiple fields while leaving the parent unchanged
	fields := logrus.Fields{
		"retries": 3,
		"status":  "healthy",
	}
	childFields := entry.WithFields(fields)
	if childFields.Data["retries"] != 3 || childFields.Data["status"] != "healthy" {
		return fmt.Errorf("expected childFields to contain added fields, got %v", childFields.Data)
	}
	if _, exists := entry.Data["retries"]; exists {
		return fmt.Errorf("expected parent entry to remain unchanged after WithFields")
	}

	// Assertion 4: Entry.WithError sets the error under the standard logrus.ErrorKey field in the entry copy
	sampleErr := errors.New("temporary network timeout")
	errEntry := entry.WithError(sampleErr)
	if errVal, ok := errEntry.Data[logrus.ErrorKey]; !ok || errVal != sampleErr {
		return fmt.Errorf("expected errEntry to contain %v at ErrorKey, got %v", sampleErr, errVal)
	}
	if _, exists := entry.Data[logrus.ErrorKey]; exists {
		return fmt.Errorf("expected parent entry to remain unchanged after WithError")
	}

	// Assertion 5: Entry.WithTime sets the timestamp on the returned entry copy
	customTime := time.Date(2026, time.September, 17, 10, 30, 0, 0, time.UTC)
	timedEntry := entry.WithTime(customTime)
	if !timedEntry.Time.Equal(customTime) {
		return fmt.Errorf("expected timedEntry.Time to equal %v, got %v", customTime, timedEntry.Time)
	}

	// Assertion 6: Entry.String serializes the entry using the logger formatter and contains the message and fields
	buf := new(bytes.Buffer)
	formatLogger := logrus.New()
	formatLogger.SetOutput(buf)
	formatLogger.SetFormatter(&logrus.TextFormatter{
		DisableColors: true,
	})
	logEntry := logrus.NewEntry(formatLogger).WithField("component", "auth-service")
	logEntry.Message = "token validated successfully"
	logEntry.Level = logrus.InfoLevel

	str, err := logEntry.String()
	if err != nil {
		return fmt.Errorf("logEntry.String returned error: %w", err)
	}
	if !strings.Contains(str, "token validated successfully") {
		return fmt.Errorf("expected logEntry.String to contain message, got %s", str)
	}
	if !strings.Contains(str, "component=auth-service") {
		return fmt.Errorf("expected logEntry.String to contain field component=auth-service, got %s", str)
	}

	return nil
}