github.com/rs/zerolog v1.15.0: WarnLevel

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/rs/zerolog.WarnLevel in pkg:golang/github.com/rs/zerolog@v1.15.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/rs/zerolog@v1.15.0
Demonstrate these symbols/APIs:
  - github.com/rs/zerolog.WarnLevel

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:f0cbb1b86232db030e86c9ff3c1dde86630aedca63ffa90c75b421b11937e4dd","contract":["zerolog.WarnLevel string representation is warn","zerolog.ParseLevel parses warn string to zerolog.WarnLevel","zerolog.Logger.Level sets the logger minimum level to zerolog.WarnLevel","zerolog.Logger configured at zerolog.WarnLevel filters out debug and info messages","zerolog.Logger configured at zerolog.WarnLevel emits warning and error messages","zerolog.SetGlobalLevel configures zerolog.GlobalLevel to zerolog.WarnLevel"],"goal":"verify github.com/rs/zerolog.WarnLevel in pkg:golang/github.com/rs/zerolog@v1.15.0","kind":"HOW","packages":["pkg:golang/github.com/rs/zerolog@v1.15.0"],"schemaVersion":1,"symbols":["github.com/rs/zerolog.WarnLevel"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/rs/zerolog@v1.15.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/rs/zerolog@v1.15.0","symbols":["github.com/rs/zerolog.WarnLevel"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/rs/zerolog v1.15.0

github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
github.com/rs/xid v1.2.1/go.mod h1:+uKXf+4Djp6Md1KODXJxgGQPKngRmWyn10oCKFzNHOQ=
github.com/rs/zerolog v1.15.0 h1:uPRuwkWF4J6fGsJ2R0Gn2jB1EQiav9k3S6CSdygQJXY=
github.com/rs/zerolog v1.15.0/go.mod h1:xYTKnLHcpfU2225ny5qZjxnj9NvkumZYjJHlAThCjNc=
github.com/zenazn/goji v0.9.0/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20190425163242-31fd60d6bfdc/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=

package main

import (
	"bytes"
	"fmt"
	"os"

	"github.com/rs/zerolog"
)

// ConfigureWarnLogger sets up a zerolog.Logger configured with WarnLevel threshold.
func ConfigureWarnLogger(buf *bytes.Buffer) zerolog.Logger {
	return zerolog.New(buf).Level(zerolog.WarnLevel)
}

func main() {
	var buf bytes.Buffer
	logger := ConfigureWarnLogger(&buf)

	// Demonstrating zerolog.WarnLevel:
	// Messages below WarnLevel (such as Info) are suppressed.
	logger.Info().Msg("this information message will be suppressed")

	// Messages at WarnLevel are recorded.
	logger.Warn().Str("component", "worker").Msg("this is a warning message")

	// Output the buffer contents
	fmt.Printf("Captured log output:\n%s", buf.String())

	// Demonstrating WarnLevel constants and parsing
	fmt.Printf("WarnLevel value: %s\n", zerolog.WarnLevel.String())
	parsedLevel, err := zerolog.ParseLevel("warn")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to parse level: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Parsed level matches: %t\n", parsedLevel == zerolog.WarnLevel)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/rs/zerolog.WarnLevel in pkg:golang/github.com/rs/zerolog@v1.15.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/rs/zerolog@v1.15.0"
  ],
  "symbols": [
    "github.com/rs/zerolog.WarnLevel"
  ]
}

package main

import (
	"bytes"
	"fmt"
	"os"
	"strings"

	"github.com/rs/zerolog"
)

func main() {
	// Assertion 1: zerolog.WarnLevel string representation is "warn"
	{
		if zerolog.WarnLevel.String() != "warn" {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected WarnLevel string to be 'warn', got %q\n", zerolog.WarnLevel.String())
			os.Exit(1)
		}
	}

	// Assertion 2: zerolog.ParseLevel parses "warn" string to zerolog.WarnLevel
	{
		level, err := zerolog.ParseLevel("warn")
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: ParseLevel('warn') returned error: %v\n", err)
			os.Exit(1)
		}
		if level != zerolog.WarnLevel {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: expected level %v, got %v\n", zerolog.WarnLevel, level)
			os.Exit(1)
		}
	}

	// Assertion 3: zerolog.Logger.Level sets the logger minimum level to zerolog.WarnLevel
	{
		var buf bytes.Buffer
		logger := zerolog.New(&buf).Level(zerolog.WarnLevel)
		if logger.GetLevel() != zerolog.WarnLevel {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected logger level %v, got %v\n", zerolog.WarnLevel, logger.GetLevel())
			os.Exit(1)
		}
	}

	// Assertion 4: zerolog.Logger configured at zerolog.WarnLevel filters out debug and info messages
	{
		var buf bytes.Buffer
		logger := zerolog.New(&buf).Level(zerolog.WarnLevel)
		logger.Debug().Msg("debug message")
		logger.Info().Msg("info message")
		if buf.Len() != 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: expected empty buffer for suppressed levels, got %q\n", buf.String())
			os.Exit(1)
		}
	}

	// Assertion 5: zerolog.Logger configured at zerolog.WarnLevel emits warning and error messages
	{
		var buf bytes.Buffer
		logger := zerolog.New(&buf).Level(zerolog.WarnLevel)
		logger.Warn().Str("alert", "low_disk").Msg("warning message")
		outWarn := buf.String()
		if !strings.Contains(outWarn, `"level":"warn"`) || !strings.Contains(outWarn, `"alert":"low_disk"`) || !strings.Contains(outWarn, `"message":"warning message"`) {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: expected warn log output, got %q\n", outWarn)
			os.Exit(1)
		}

		buf.Reset()
		logger.Error().Msg("error message")
		outErr := buf.String()
		if !strings.Contains(outErr, `"level":"error"`) || !strings.Contains(outErr, `"message":"error message"`) {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: expected error log output, got %q\n", outErr)
			os.Exit(1)
		}
	}

	// Assertion 6: zerolog.SetGlobalLevel configures zerolog.GlobalLevel to zerolog.WarnLevel
	{
		origLevel := zerolog.GlobalLevel()
		zerolog.SetGlobalLevel(zerolog.WarnLevel)
		if zerolog.GlobalLevel() != zerolog.WarnLevel {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: GlobalLevel is not WarnLevel\n")
			os.Exit(1)
		}
		zerolog.SetGlobalLevel(origLevel)
	}

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