golang.org/x/net v0.47.0

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 pkg:golang/golang.org/x/net@v0.47.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/net@v0.47.0

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:sha256:09f6b15367fa8a6c5659a2c6c08f7ba5a96fa693df6c16f46fdcb1ce3a212c2c","contract":["html.Parse parses valid HTML and returns root node containing html, head, and body elements","html.Render serializes html.Node tree back to valid HTML string","html.EscapeString and html.UnescapeString handle HTML special characters correctly","atom.Lookup returns correct non-zero Atom for known HTML tag names and returns 0 for unknown tags","atom.String returns string representation matching tag name"],"goal":"verify pkg:golang/golang.org/x/net@v0.47.0","kind":"HOW","packages":["pkg:golang/golang.org/x/net@v0.47.0"],"schemaVersion":1},"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@v0.47.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/net@v0.47.0","verifierAdapter":"golang@1"}

module example.com/sample

go 1.24.0

require golang.org/x/net v0.47.0

golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=

package main

import (
	"bytes"
	"fmt"
	"strings"

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

func main() {
	raw := `<!DOCTYPE html><html><head><title>Test</title></head><body><h1>Hello CodeSampleX</h1><p>Testing x/net html</p></body></html>`
	doc, err := html.Parse(strings.NewReader(raw))
	if err != nil {
		panic(err)
	}

	var buf bytes.Buffer
	if err := html.Render(&buf, doc); err != nil {
		panic(err)
	}
	fmt.Printf("Rendered: %s\n", buf.String())

	escaped := html.EscapeString("<hello & world>")
	fmt.Printf("Escaped: %s\n", escaped)
	unescaped := html.UnescapeString(escaped)
	fmt.Printf("Unescaped: %s\n", unescaped)

	a := atom.Lookup([]byte("body"))
	fmt.Printf("Atom for body: %s (%d)\n", a.String(), uint32(a))
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/net@v0.47.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/net@v0.47.0"
  ]
}

package main

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

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

func main() {
	// 1. html.Parse parses valid HTML and returns root node containing html, head, and body elements
	rawHTML := `<!DOCTYPE html><html><head><title>Contract Test</title></head><body><p id="msg">Hello CodeSampleX</p></body></html>`
	doc, err := html.Parse(strings.NewReader(rawHTML))
	if err != nil {
		fmt.Fprintf(os.Stderr, "Contract 1 failed: html.Parse error: %v\n", err)
		os.Exit(1)
	}

	var foundBody, foundHead, foundHtml bool
	var walk func(*html.Node)
	walk = func(n *html.Node) {
		if n.Type == html.ElementNode {
			switch n.DataAtom {
			case atom.Html:
				foundHtml = true
			case atom.Head:
				foundHead = true
			case atom.Body:
				foundBody = true
			}
		}
		for c := n.FirstChild; c != nil; c = c.NextSibling {
			walk(c)
		}
	}
	walk(doc)

	if !foundHtml || !foundHead || !foundBody {
		fmt.Fprintf(os.Stderr, "Contract 1 failed: missing html (%t), head (%t), or body (%t)\n", foundHtml, foundHead, foundBody)
		os.Exit(1)
	}

	// 2. html.Render serializes html.Node tree back to valid HTML string
	var rendered bytes.Buffer
	if err := html.Render(&rendered, doc); err != nil {
		fmt.Fprintf(os.Stderr, "Contract 2 failed: html.Render error: %v\n", err)
		os.Exit(1)
	}
	if !strings.Contains(rendered.String(), "<p id=\"msg\">Hello CodeSampleX</p>") {
		fmt.Fprintf(os.Stderr, "Contract 2 failed: rendered HTML does not contain expected snippet: %q\n", rendered.String())
		os.Exit(1)
	}

	// 3. html.EscapeString and html.UnescapeString handle HTML special characters correctly
	plain := `<script>alert("hello & goodbye")</script>`
	escaped := html.EscapeString(plain)
	if !strings.Contains(escaped, "&lt;script&gt;") || !strings.Contains(escaped, "&amp;") {
		fmt.Fprintf(os.Stderr, "Contract 3 failed: escape output invalid: %q\n", escaped)
		os.Exit(1)
	}
	unescaped := html.UnescapeString(escaped)
	if unescaped != plain {
		fmt.Fprintf(os.Stderr, "Contract 3 failed: unescape expected %q, got %q\n", plain, unescaped)
		os.Exit(1)
	}

	// 4. atom.Lookup returns correct non-zero Atom for known HTML tag names and returns 0 for unknown tags
	lookupBody := atom.Lookup([]byte("body"))
	if lookupBody != atom.Body || lookupBody == 0 {
		fmt.Fprintf(os.Stderr, "Contract 4 failed: atom.Lookup(\"body\") expected atom.Body (%d), got %d\n", atom.Body, lookupBody)
		os.Exit(1)
	}
	lookupUnknown := atom.Lookup([]byte("notarealtag12345"))
	if lookupUnknown != 0 {
		fmt.Fprintf(os.Stderr, "Contract 4 failed: atom.Lookup for unknown tag expected 0, got %d\n", lookupUnknown)
		os.Exit(1)
	}

	// 5. atom.String returns string representation matching tag name
	if atom.Body.String() != "body" {
		fmt.Fprintf(os.Stderr, "Contract 5 failed: atom.Body.String() expected \"body\", got %q\n", atom.Body.String())
		os.Exit(1)
	}
	if atom.Head.String() != "head" {
		fmt.Fprintf(os.Stderr, "Contract 5 failed: atom.Head.String() expected \"head\", got %q\n", atom.Head.String())
		os.Exit(1)
	}

	fmt.Println("PASS: all contracts satisfied")
}