// Vectors mirror ref/hare/strings/utf8.ha where ww can express them.
// External strings_test package per the Go foo_test idiom (rule-5/9
// carve-out, task #16); the shared streq helper lives in
// helpers_test.ww — same-package test files compose in dir-mode
// (the package, not the file, is the unit of testing).
package strings_test;

import strings;
import encoding.utf8;

// ref/hare/strings/utf8.ha:31. Validation-half coverage lives in
// lib/encoding/utf8 (utf8test) per CLAUDE.md rule 9 carve-out.

@test fn utf8_roundtrip_cases() void = {
	let s: str = "hello";
	let b: []u8 = strings.toutf8(s);
	assert(!(b.len != 5));
	assert(!(b[0] != 104u8));	// 'h'
	let r: str = strings.frombytes(b);
	assert(!(!streq(r, "hello")));
	assert(!(r.ptr != s.ptr));	// borrowed, not copied
};