github.com/davecgh/go-spew v1.1.1: spew.Sdump

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/davecgh/go-spew/spew.Sdump in pkg:golang/github.com/davecgh/go-spew@v1.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/davecgh/go-spew@v1.1.1
Demonstrate these symbols/APIs:
  - github.com/davecgh/go-spew/spew.Sdump

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:dcc064eef11722f595022bfd78881083ea9a8c989249f2c66aa3ab94faeefffe","contract":["spew.Sdump formats structs with type names, field names, and value types","spew.Sdump formats slices and maps with length and capacity details","spew.Sdump formats multiple arguments separated by newlines","spew.Sdump formats nil pointers and nil interfaces safely without panicking"],"goal":"verify github.com/davecgh/go-spew/spew.Sdump in pkg:golang/github.com/davecgh/go-spew@v1.1.1","kind":"HOW","packages":["pkg:golang/github.com/davecgh/go-spew@v1.1.1"],"schemaVersion":1,"symbols":["github.com/davecgh/go-spew/spew.Sdump"]},"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/davecgh/go-spew@v1.1.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/davecgh/go-spew@v1.1.1","symbols":["github.com/davecgh/go-spew/spew.Sdump"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.22

require github.com/davecgh/go-spew v1.1.1

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=

package main

import (
	"fmt"

	"github.com/davecgh/go-spew/spew"
)

type Config struct {
	Host    string
	Port    int
	Enabled bool
}

func main() {
	cfg := Config{
		Host:    "localhost",
		Port:    8080,
		Enabled: true,
	}

	dump := spew.Sdump(cfg)
	fmt.Print(dump)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/davecgh/go-spew/spew.Sdump in pkg:golang/github.com/davecgh/go-spew@v1.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/davecgh/go-spew@v1.1.1"
  ],
  "symbols": [
    "github.com/davecgh/go-spew/spew.Sdump"
  ]
}

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/davecgh/go-spew/spew"
)

type Record struct {
	ID    int
	Title string
}

func main() {
	// Assertion 1: spew.Sdump formats structs with type names, field names, and value types
	rec := Record{
		ID:    42,
		Title: "Test Record",
	}
	dump1 := spew.Sdump(rec)
	if !strings.Contains(dump1, "(main.Record)") {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected (main.Record) in dump, got: %s\n", dump1)
		os.Exit(1)
	}
	if !strings.Contains(dump1, "ID: (int) 42") {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected ID: (int) 42 in dump, got: %s\n", dump1)
		os.Exit(1)
	}
	if !strings.Contains(dump1, "Title: (string) (len=11) \"Test Record\"") {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected Title string info in dump, got: %s\n", dump1)
		os.Exit(1)
	}

	// Assertion 2: spew.Sdump formats slices and maps with length and capacity details
	nums := []int{10, 20, 30}
	dump2 := spew.Sdump(nums)
	if !strings.Contains(dump2, "([]int) (len=3 cap=3)") {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected slice length and capacity in dump, got: %s\n", dump2)
		os.Exit(1)
	}
	if !strings.Contains(dump2, "(int) 10") || !strings.Contains(dump2, "(int) 20") || !strings.Contains(dump2, "(int) 30") {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected elements in dump, got: %s\n", dump2)
		os.Exit(1)
	}

	// Assertion 3: spew.Sdump formats multiple arguments separated by newlines
	dump3 := spew.Sdump("hello", 100, true)
	expectedLines := []string{
		"(string) (len=5) \"hello\"",
		"(int) 100",
		"(bool) true",
	}
	for _, expected := range expectedLines {
		if !strings.Contains(dump3, expected) {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected %q in dump, got: %s\n", expected, dump3)
			os.Exit(1)
		}
	}

	// Assertion 4: spew.Sdump formats nil pointers and nil interfaces safely without panicking
	var nilPtr *Record
	var nilIface any
	dump4 := spew.Sdump(nilPtr, nilIface)
	if !strings.Contains(dump4, "(*main.Record)(<nil>)") {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected (*main.Record)(<nil>) in dump, got: %s\n", dump4)
		os.Exit(1)
	}
	if !strings.Contains(dump4, "(interface {}) <nil>") {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected (interface {}) <nil> in dump, got: %s\n", dump4)
		os.Exit(1)
	}

	fmt.Println("All spew.Sdump contract assertions passed.")
}