golang.org/x/net v0.61.0: atom.H4

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 golang.org/x/net/html/atom.H4 in pkg:golang/golang.org/x/net@v0.61.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/net@v0.61.0
Demonstrate these symbols/APIs:
  - golang.org/x/net/html/atom.H4

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:a617fd0a6bc73580b923a3d642d03bde673f1f18b3cf055fd8a9d56e4308e30a","contract":["atom.H4 is a non-zero Atom value representing HTML h4 heading tag","atom.H4.String() returns string literal \"h4\"","atom.Lookup returns atom.H4 for byte slice []byte(\"h4\")","atom.Lookup is case-sensitive and returns 0 for byte slice []byte(\"H4\")","atom.String returns \"h4\" for byte slice []byte(\"h4\")"],"goal":"verify golang.org/x/net/html/atom.H4 in pkg:golang/golang.org/x/net@v0.61.0","kind":"HOW","packages":["pkg:golang/golang.org/x/net@v0.61.0"],"schemaVersion":1,"symbols":["golang.org/x/net/html/atom.H4"]},"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/golang.org/x/net@v0.61.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/net@v0.61.0","symbols":["golang.org/x/net/html/atom.H4"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require golang.org/x/net v0.61.0

golang.org/x/net v0.61.0 h1:RR+6j/BTBCrggOLugxa+66R8FvoN6MHlzDlZIbN9YFw=
golang.org/x/net v0.61.0/go.mod h1:WgDCOTH8iwtB66T4/GfI94AHo/hhdb7Hah9NDseQfiI=

package main

import (
	"fmt"

	"golang.org/x/net/html/atom"
)

func main() {
	// Demonstrating golang.org/x/net/html/atom.H4
	// atom.H4 is an integer code representing the HTML <h4> tag name.

	// 1. Value and type
	h4Atom := atom.H4
	fmt.Printf("atom.H4 raw value: %#x\n", uint32(h4Atom))

	// 2. String representation via Atom.String()
	name := h4Atom.String()
	fmt.Printf("atom.H4 name: %s\n", name)

	// 3. Lookup by byte slice
	lookedUp := atom.Lookup([]byte("h4"))
	fmt.Printf("atom.Lookup(\"h4\") == atom.H4: %t\n", lookedUp == atom.H4)

	// 4. String lookup via atom.String
	strResult := atom.String([]byte("h4"))
	fmt.Printf("atom.String(\"h4\"): %s\n", strResult)

	fmt.Println("golang.org/x/net/html/atom.H4 demonstrated successfully.")
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/net/html/atom.H4 in pkg:golang/golang.org/x/net@v0.61.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/net@v0.61.0"
  ],
  "symbols": [
    "golang.org/x/net/html/atom.H4"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/net/html/atom"
)

func main() {
	// Assertion 1: atom.H4 is a non-zero Atom value representing HTML h4 heading tag
	{
		if atom.H4 == 0 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: atom.H4 is zero\n")
			os.Exit(1)
		}
	}

	// Assertion 2: atom.H4.String() returns string literal "h4"
	{
		str := atom.H4.String()
		if str != "h4" {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: expected \"h4\", got %q\n", str)
			os.Exit(1)
		}
	}

	// Assertion 3: atom.Lookup returns atom.H4 for byte slice []byte("h4")
	{
		lookedUp := atom.Lookup([]byte("h4"))
		if lookedUp != atom.H4 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected atom.H4 (%#x), got %#x\n", atom.H4, lookedUp)
			os.Exit(1)
		}
	}

	// Assertion 4: atom.Lookup is case-sensitive and returns 0 for byte slice []byte("H4")
	{
		lookedUpUpper := atom.Lookup([]byte("H4"))
		if lookedUpUpper != 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: expected 0 for uppercase H4 lookup, got %#x\n", lookedUpUpper)
			os.Exit(1)
		}
	}

	// Assertion 5: atom.String returns "h4" for byte slice []byte("h4")
	{
		str := atom.String([]byte("h4"))
		if str != "h4" {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: expected \"h4\", got %q\n", str)
			os.Exit(1)
		}
	}

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