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

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.NFC 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.NFC

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:sha256:8cdce9ae7606b8e85211ef60832bd4cfb36420faddd2f7d892ffcaaee6e20507","contract":["norm.NFC.String composes decomposed NFD combining characters into canonical NFC characters","norm.NFC.Bytes normalizes byte slice with combining characters to canonical NFC bytes","norm.NFC.IsNormalString returns false for decomposed NFD string and true for composed NFC string","norm.NFC.IsNormal returns false for decomposed NFD byte slice and true for composed NFC byte slice","norm.NFC.String preserves already normalized ASCII and NFC strings unchanged","norm.NFC.AppendString appends normalized NFC representation to destination buffer"],"goal":"verify norm.NFC 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.NFC"]},"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.NFC"],"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 (
	"bytes"
	"fmt"

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

func main() {
	// NFD representation: 'e' + combining acute accent (\u0301)
	decomposed := "e\u0301"
	// Canonical NFC representation: 'é' (\u00e9)
	composedExpected := "\u00e9"

	fmt.Printf("Original NFD string: %q (bytes: % x, normal NFC: %t)\n",
		decomposed, []byte(decomposed), norm.NFC.IsNormalString(decomposed))

	// Normalize string to NFC
	normalized := norm.NFC.String(decomposed)
	fmt.Printf("Normalized NFC string: %q (bytes: % x, normal NFC: %t)\n",
		normalized, []byte(normalized), norm.NFC.IsNormalString(normalized))

	if normalized == composedExpected {
		fmt.Println("String normalization to NFC succeeded.")
	}

	// Normalize byte slice to NFC
	decomposedBytes := []byte(decomposed)
	normalizedBytes := norm.NFC.Bytes(decomposedBytes)
	if bytes.Equal(normalizedBytes, []byte(composedExpected)) {
		fmt.Println("Byte slice normalization to NFC succeeded.")
	}

	// Append normalized text to buffer
	buf := []byte("Result: ")
	buf = norm.NFC.AppendString(buf, decomposed)
	fmt.Printf("Appended buffer: %s\n", string(buf))
}

{
  "schemaVersion": 1,
  "goal": "verify norm.NFC in pkg:golang/golang.org/x/text@v0.3.2",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/text@v0.3.2"
  ],
  "symbols": [
    "norm.NFC"
  ]
}

package main

import (
	"bytes"
	"fmt"
	"os"

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

func main() {
	decomposedLatin := "e\u0301"       // 'e' + combining acute accent (\u0301)
	composedLatin := "\u00e9"         // 'é' (\u00e9)
	decomposedHangul := "\u1100\u1161" // Hangul Choseong Kiyeok + Jungseong A
	composedHangul := "\uac00"        // Hangul Syllable Ga (\uac00)

	// 1. norm.NFC.String composes decomposed NFD combining characters into canonical NFC characters
	if res := norm.NFC.String(decomposedLatin); res != composedLatin {
		fmt.Fprintf(os.Stderr, "assertion 1 failed for latin: expected %q, got %q\n", composedLatin, res)
		os.Exit(1)
	}
	if res := norm.NFC.String(decomposedHangul); res != composedHangul {
		fmt.Fprintf(os.Stderr, "assertion 1 failed for hangul: expected %q, got %q\n", composedHangul, res)
		os.Exit(1)
	}

	// 2. norm.NFC.Bytes normalizes byte slice with combining characters to canonical NFC bytes
	latinBytesNFD := []byte(decomposedLatin)
	latinBytesNFC := []byte(composedLatin)
	if res := norm.NFC.Bytes(latinBytesNFD); !bytes.Equal(res, latinBytesNFC) {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected %v, got %v\n", latinBytesNFC, res)
		os.Exit(1)
	}

	// 3. norm.NFC.IsNormalString returns false for decomposed NFD string and true for composed NFC string
	if norm.NFC.IsNormalString(decomposedLatin) {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected false for decomposedLatin\n")
		os.Exit(1)
	}
	if !norm.NFC.IsNormalString(composedLatin) {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected true for composedLatin\n")
		os.Exit(1)
	}

	// 4. norm.NFC.IsNormal returns false for decomposed NFD byte slice and true for composed NFC byte slice
	if norm.NFC.IsNormal(latinBytesNFD) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected false for latinBytesNFD\n")
		os.Exit(1)
	}
	if !norm.NFC.IsNormal(latinBytesNFC) {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected true for latinBytesNFC\n")
		os.Exit(1)
	}

	// 5. norm.NFC.String preserves already normalized ASCII and NFC strings unchanged
	asciiStr := "CodeSampleX"
	if res := norm.NFC.String(asciiStr); res != asciiStr {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: expected %q, got %q\n", asciiStr, res)
		os.Exit(1)
	}
	if res := norm.NFC.String(composedLatin); res != composedLatin {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: expected %q, got %q\n", composedLatin, res)
		os.Exit(1)
	}

	// 6. norm.NFC.AppendString appends normalized NFC representation to destination buffer
	buf := []byte("prefix: ")
	buf = norm.NFC.AppendString(buf, decomposedLatin)
	expectedBuf := []byte("prefix: \u00e9")
	if !bytes.Equal(buf, expectedBuf) {
		fmt.Fprintf(os.Stderr, "assertion 6 failed: expected %q, got %q\n", expectedBuf, buf)
		os.Exit(1)
	}

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