golang.org/x/text v0.3.2: norm.NFD

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 norm.NFD in pkg:golang/golang.org/x/text@v0.3.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/text@v0.3.2
Demonstrate these symbols/APIs:
  - norm.NFD
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:a6d10a7edc58ee83664681f2a35589ae9509fcb1098af1fca477307660f06ee9","contract":["norm.NFD.String decomposes precomposed characters into canonical decomposed form","norm.NFD.Bytes decomposes UTF-8 byte slice into canonical decomposed byte slice","norm.NFD.IsNormal returns false for precomposed NFC byte slice and true for decomposed NFD byte slice","norm.NFD.IsNormalString returns false for precomposed NFC string and true for decomposed NFD string","norm.NFD.String leaves ASCII string unchanged","norm.NFD.Reader transforms stream to decomposed form"],"goal":"verify norm.NFD in pkg:golang/golang.org/x/text@v0.3.2","kind":"HOW","packages":["pkg:golang/golang.org/x/text@v0.3.2"],"schemaVersion":1,"symbols":["norm.NFD"]},"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/text@v0.3.2"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/text@v0.3.2","symbols":["norm.NFD"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.23

require golang.org/x/text v0.3.2

golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

package main

import (
	"fmt"

	"golang.org/x/text/unicode/norm"
)

func main() {
	precomposed := "café"
	decomposed := norm.NFD.String(precomposed)

	fmt.Printf("Original string: %s (bytes: %d)\n", precomposed, len(precomposed))
	fmt.Printf("Decomposed string: %s (bytes: %d)\n", decomposed, len(decomposed))
	fmt.Printf("Is normal NFD: %t\n", norm.NFD.IsNormalString(decomposed))
}

{
  "schemaVersion": 1,
  "goal": "verify norm.NFD in pkg:golang/golang.org/x/text@v0.3.2",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/text@v0.3.2"
  ],
  "symbols": [
    "norm.NFD"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

package main

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

	"golang.org/x/text/unicode/norm"
)

func main() {
	// 1. norm.NFD.String decomposes precomposed characters into canonical decomposed form
	precomposed := "café"
	expectedDecomposed := "cafe\u0301"
	decomposed := norm.NFD.String(precomposed)
	if decomposed != expectedDecomposed {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected %q, got %q\n", expectedDecomposed, decomposed)
		os.Exit(1)
	}

	// 2. norm.NFD.Bytes decomposes UTF-8 byte slice into canonical decomposed byte slice
	decomposedBytes := norm.NFD.Bytes([]byte(precomposed))
	if !bytes.Equal(decomposedBytes, []byte(expectedDecomposed)) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected %v, got %v\n", []byte(expectedDecomposed), decomposedBytes)
		os.Exit(1)
	}

	// 3. norm.NFD.IsNormal returns false for precomposed NFC byte slice and true for decomposed NFD byte slice
	if norm.NFD.IsNormal([]byte(precomposed)) {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected IsNormal([]byte) to be false for NFC\n")
		os.Exit(1)
	}
	if !norm.NFD.IsNormal([]byte(expectedDecomposed)) {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected IsNormal([]byte) to be true for NFD\n")
		os.Exit(1)
	}

	// 4. norm.NFD.IsNormalString returns false for precomposed NFC string and true for decomposed NFD string
	if norm.NFD.IsNormalString(precomposed) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected IsNormalString to be false for NFC\n")
		os.Exit(1)
	}
	if !norm.NFD.IsNormalString(expectedDecomposed) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected IsNormalString to be true for NFD\n")
		os.Exit(1)
	}

	// 5. norm.NFD.String leaves ASCII string unchanged
	ascii := "hello world 123 !@#"
	if norm.NFD.String(ascii) != ascii {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: ASCII string modified by NFD\n")
		os.Exit(1)
	}

	// 6. norm.NFD.Reader transforms stream to decomposed form
	reader := norm.NFD.Reader(strings.NewReader(precomposed))
	readBuf, err := io.ReadAll(reader)
	if err != nil {
		fmt.Fprintf(os.Stderr, "assertion 6 failed with error: %v\n", err)
		os.Exit(1)
	}
	if string(readBuf) != expectedDecomposed {
		fmt.Fprintf(os.Stderr, "assertion 6 failed: reader output %q != expected %q\n", string(readBuf), expectedDecomposed)
		os.Exit(1)
	}

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