golang.org/x/text v0.24.0

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/text@v0.24.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/text@v0.24.0

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:sha256:1151d301c3e9cf06fc7ef152b74de5c21a0ad6b314a1881ed69c1a36ce6ae982","contract":["language.Parse and language.NewMatcher match requested BCP 47 language tags against supported preferences","cases.Title, cases.Upper and cases.Lower apply language-aware case transformations","norm.NFC, norm.NFD and norm.NFKD perform canonical and compatibility Unicode normalization","width.Fold normalizes fullwidth characters to standard halfwidth ASCII forms","bidirule.ValidString validates directional strings according to RFC 5893"],"goal":"verify pkg:golang/golang.org/x/text@v0.24.0","kind":"HOW","packages":["pkg:golang/golang.org/x/text@v0.24.0"],"schemaVersion":1},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/text@v0.24.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/text@v0.24.0","verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require golang.org/x/text v0.24.0

golang.org/x/text v0.24.0 h1:dd5Bzh4yt5KYA8f9CJHCP4FB4D51c2c6JvN37xJJkJ0=
golang.org/x/text v0.24.0/go.mod h1:L8rBsPeo2pSS+xqN0d5u2ikmjtmoJbDBT1b7nHvFCdU=

package main

import (
	"fmt"

	"golang.org/x/text/cases"
	"golang.org/x/text/language"
	"golang.org/x/text/secure/bidirule"
	"golang.org/x/text/unicode/norm"
	"golang.org/x/text/width"
)

func main() {
	// 1. Language matching
	serverLangs := []language.Tag{language.English, language.German, language.French}
	matcher := language.NewMatcher(serverLangs)
	tag, index, conf := matcher.Match(language.BritishEnglish)
	fmt.Printf("Matched: %s at %d (%v)\n", tag, index, conf)

	// 2. Locale-sensitive casing
	fmt.Printf("Turkish upper: %s\n", cases.Upper(language.Turkish).String("istanbul"))

	// 3. Unicode normalization
	fmt.Printf("NFC: %s\n", norm.NFC.String("e\u0301"))

	// 4. Width folding
	fmt.Printf("Fold: %s\n", width.Fold.String("Ｈｅｌｌｏ １２３！"))

	// 5. Bidi rule validation
	fmt.Printf("Bidi valid: %t\n", bidirule.ValidString("example"))
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/text@v0.24.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/text@v0.24.0"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/text/cases"
	"golang.org/x/text/language"
	"golang.org/x/text/secure/bidirule"
	"golang.org/x/text/unicode/norm"
	"golang.org/x/text/width"
)

func main() {
	// Assertion 1: language.Parse and language.NewMatcher match requested BCP 47 language tags against supported preferences
	supported := []language.Tag{language.English, language.German, language.French}
	matcher := language.NewMatcher(supported)

	parsedTag, err := language.Parse("de-AT")
	if err != nil {
		fmt.Fprintf(os.Stderr, "Assertion 1 failed: language.Parse error: %v\n", err)
		os.Exit(1)
	}

	_, index, conf := matcher.Match(parsedTag)
	if supported[index] != language.German || index != 1 || conf < language.High {
		fmt.Fprintf(os.Stderr, "Assertion 1 failed: expected German at index 1 with High+ conf, got %v at %d (%v)\n", supported[index], index, conf)
		os.Exit(1)
	}

	// Assertion 2: cases.Title, cases.Upper and cases.Lower apply language-aware case transformations
	trUpper := cases.Upper(language.Turkish).String("istanbul")
	enUpper := cases.Upper(language.English).String("istanbul")
	if trUpper != "İSTANBUL" || enUpper != "ISTANBUL" {
		fmt.Fprintf(os.Stderr, "Assertion 2 failed: Upper expected tr='İSTANBUL', en='ISTANBUL', got tr='%s', en='%s'\n", trUpper, enUpper)
		os.Exit(1)
	}

	trLower := cases.Lower(language.Turkish).String("ISTANBUL")
	enLower := cases.Lower(language.English).String("ISTANBUL")
	if trLower != "ıstanbul" || enLower != "istanbul" {
		fmt.Fprintf(os.Stderr, "Assertion 2 failed: Lower expected tr='ıstanbul', en='istanbul', got tr='%s', en='%s'\n", trLower, enLower)
		os.Exit(1)
	}

	trTitle := cases.Title(language.Turkish).String("istanbul")
	enTitle := cases.Title(language.English).String("istanbul")
	if trTitle != "İstanbul" || enTitle != "Istanbul" {
		fmt.Fprintf(os.Stderr, "Assertion 2 failed: Title expected tr='İstanbul', en='Istanbul', got tr='%s', en='%s'\n", trTitle, enTitle)
		os.Exit(1)
	}

	// Assertion 3: norm.NFC, norm.NFD and norm.NFKD perform canonical and compatibility Unicode normalization
	decomposed := "e\u0301" // e + combining acute accent
	composed := norm.NFC.String(decomposed)
	if composed != "é" || len(composed) != 2 {
		fmt.Fprintf(os.Stderr, "Assertion 3 failed: NFC expected 'é' (2 bytes), got '%s' (%d bytes)\n", composed, len(composed))
		os.Exit(1)
	}

	if norm.NFD.String("é") != decomposed {
		fmt.Fprintf(os.Stderr, "Assertion 3 failed: NFD did not match decomposed form\n")
		os.Exit(1)
	}

	if norm.NFKD.String("fi") != "fi" {
		fmt.Fprintf(os.Stderr, "Assertion 3 failed: NFKD ligature decomposition failed\n")
		os.Exit(1)
	}

	// Assertion 4: width.Fold normalizes fullwidth characters to standard halfwidth ASCII forms
	fullwidth := "Ｈｅｌｌｏ １２３！"
	folded := width.Fold.String(fullwidth)
	if folded != "Hello 123!" {
		fmt.Fprintf(os.Stderr, "Assertion 4 failed: width.Fold expected 'Hello 123!', got '%s'\n", folded)
		os.Exit(1)
	}

	// Assertion 5: bidirule.ValidString validates directional strings according to RFC 5893
	if !bidirule.ValidString("example") {
		fmt.Fprintf(os.Stderr, "Assertion 5 failed: bidirule.ValidString('example') returned false\n")
		os.Exit(1)
	}
	if !bidirule.ValidString("العربية") {
		fmt.Fprintf(os.Stderr, "Assertion 5 failed: bidirule.ValidString('العربية') returned false\n")
		os.Exit(1)
	}
	if bidirule.ValidString("example العربية") {
		fmt.Fprintf(os.Stderr, "Assertion 5 failed: bidirule.ValidString('example العربية') returned true for mixed invalid label\n")
		os.Exit(1)
	}

	fmt.Println("Contract passed: all assertions verified successfully.")
}