golang.org/x/net v0.0.0-20191119073136-fc4aabc6c914: atom.A

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.A in pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914
Demonstrate these symbols/APIs:
  - golang.org/x/net/html/atom.A

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:b60f8d0f0a182172a4bef504d551404570699d8c2dd85d6db06b5a3c8137bf3c","contract":["atom.A constant is non-zero and atom.A.String returns \"a\"","atom.Lookup on byte slice \"a\" returns atom.A while case-mismatched or unknown input returns 0","atom.String on byte slice \"a\" returns identical string value \"a\""],"goal":"verify golang.org/x/net/html/atom.A in pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914","kind":"HOW","packages":["pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914"],"schemaVersion":1,"symbols":["golang.org/x/net/html/atom.A"]},"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@v0.0.0-20191119073136-fc4aabc6c914"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914","symbols":["golang.org/x/net/html/atom.A"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.21

require golang.org/x/net v0.0.0-20191119073136-fc4aabc6c914

golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/net v0.0.0-20191119073136-fc4aabc6c914 h1:MlY3mEfbnWGmUi4rtHOtNnnnN4UJRGSyLPx+DXA5Sq4=
golang.org/x/net v0.0.0-20191119073136-fc4aabc6c914/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
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=

package main

import (
	"fmt"

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

func main() {
	aAtom := atom.A
	fmt.Printf("Atom: %d, String: %s\n", aAtom, aAtom.String())

	lookedUp := atom.Lookup([]byte("a"))
	fmt.Printf("Lookup 'a': %d (matches atom.A: %t)\n", lookedUp, lookedUp == aAtom)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/net/html/atom.A in pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/net@v0.0.0-20191119073136-fc4aabc6c914"
  ],
  "symbols": [
    "golang.org/x/net/html/atom.A"
  ]
}

package main

import (
	"fmt"
	"os"

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

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

func runContractTests() error {
	// 1. atom.A constant is non-zero and atom.A.String returns "a"
	if atom.A == 0 {
		return fmt.Errorf("expected atom.A != 0, got 0")
	}
	if got := atom.A.String(); got != "a" {
		return fmt.Errorf("expected atom.A.String() == %q, got %q", "a", got)
	}

	// 2. atom.Lookup on byte slice "a" returns atom.A while case-mismatched or unknown input returns 0
	if lookedUp := atom.Lookup([]byte("a")); lookedUp != atom.A {
		return fmt.Errorf("expected atom.Lookup([]byte(\"a\")) == atom.A (%d), got %d", atom.A, lookedUp)
	}
	if upper := atom.Lookup([]byte("A")); upper != 0 {
		return fmt.Errorf("expected atom.Lookup([]byte(\"A\")) == 0, got %d", upper)
	}
	if unknown := atom.Lookup([]byte("unknown_tag_xyz")); unknown != 0 {
		return fmt.Errorf("expected atom.Lookup(unknown) == 0, got %d", unknown)
	}

	// 3. atom.String on byte slice "a" returns identical string value "a"
	if s := atom.String([]byte("a")); s != "a" {
		return fmt.Errorf("expected atom.String([]byte(\"a\")) == %q, got %q", "a", s)
	}

	return nil
}