golang.org/x/net v0.24.0: atom.H3

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.H3 in pkg:golang/golang.org/x/net@v0.24.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/net@v0.24.0
Demonstrate these symbols/APIs:
  - golang.org/x/net/html/atom.H3

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:e9f92b0081741fc80357f8807f4789b4f800b7c943c07e755b13dc53df4820f8","contract":["atom.H3 represents the HTML h3 element and is non-zero","atom.H3.String returns string \"h3\"","atom.Lookup with byte slice \"h3\" returns atom.H3","atom.String with byte slice \"h3\" returns string \"h3\"","atom.Lookup returns 0 for unrecognized tag names"],"goal":"verify golang.org/x/net/html/atom.H3 in pkg:golang/golang.org/x/net@v0.24.0","kind":"HOW","packages":["pkg:golang/golang.org/x/net@v0.24.0"],"schemaVersion":1,"symbols":["golang.org/x/net/html/atom.H3"]},"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/golang.org/x/net@v0.24.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/net@v0.24.0","symbols":["golang.org/x/net/html/atom.H3"],"verifierAdapter":"golang@1"}

module sample

go 1.22

require golang.org/x/net v0.24.0

golang.org/x/net v0.24.0 h1:1PcaxkF854Fu3+lvBIx5SYn9wRlBzzcnHZSiaFFAb0w=
golang.org/x/net v0.24.0/go.mod h1:2Q7sJY5mzlzWjKtYUEXSlBWCdyaioyXzRB2RtU8KVE8=

package main

import (
	"fmt"

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

// GetH3Atom returns the atom representation of the HTML h3 element.
func GetH3Atom() atom.Atom {
	return atom.H3
}

func main() {
	a := GetH3Atom()
	fmt.Printf("Atom: %s (value: %d)\n", a.String(), a)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/net/html/atom.H3 in pkg:golang/golang.org/x/net@v0.24.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/net@v0.24.0"
  ],
  "symbols": [
    "golang.org/x/net/html/atom.H3"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	// 1. atom.H3 represents the HTML h3 element and is non-zero
	if atom.H3 == 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.H3 to be non-zero\n")
		os.Exit(1)
	}

	// 2. atom.H3.String returns string "h3"
	if s := atom.H3.String(); s != "h3" {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.H3.String() == %q, got %q\n", "h3", s)
		os.Exit(1)
	}

	// 3. atom.Lookup with byte slice "h3" returns atom.H3
	if a := atom.Lookup([]byte("h3")); a != atom.H3 {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.Lookup([]byte(\"h3\")) == atom.H3, got %v\n", a)
		os.Exit(1)
	}

	// 4. atom.String with byte slice "h3" returns string "h3"
	if s := atom.String([]byte("h3")); s != "h3" {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.String([]byte(\"h3\")) == %q, got %q\n", "h3", s)
		os.Exit(1)
	}

	// 5. atom.Lookup returns 0 for unrecognized tag names
	if a := atom.Lookup([]byte("unrecognized_html_tag_name")); a != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.Lookup for unknown tag to return 0, got %v\n", a)
		os.Exit(1)
	}
	if a := atom.Lookup([]byte("H3")); a != 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected atom.Lookup for uppercase tag to return 0, got %v\n", a)
		os.Exit(1)
	}

	fmt.Println("PASS: all contract assertions passed")
}