{

private ?PDO $admin = null;

private string $host = '';

private string $port = '';

private string $password = '';

private array $created = [];

/** Gurmukhi, transliteration, translation, other scripts, and four-byte characters. */

private const TABLE = "CREATE TABLE gurbani (

) DEFAULT CHARSET=utf8mb4";

private const WORDS = "CREATE TABLE words (word varchar(100) COLLATE utf8mb4_0900_ai_ci PRIMARY KEY, meaning varchar(100)) DEFAULT CHARSET=utf8mb4";

protected function setUp(): void

{

$host = getenv('DB_HOST');

if (!$host || !extension_loaded('pdo_mysql')) {

$this->markTestSkipped('DB_HOST not set.');

}

$this->host = $host;

$this->port = getenv('DB_PORT') ?: '3306';

$this->password = getenv('DB_ROOT_PASSWORD') ?: 'rootpass';

$this->admin = new PDO("mysql:host={$this->host};port={$this->port};charset=utf8mb4", 'root', $this->password,

[PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);

ParamsFactory::set(new DefaultParams);

}

protected function tearDown(): void

{

foreach ($this->created as $db) {

$this->admin?->exec("DROP DATABASE IF EXISTS `$db`");

}

ParamsFactory::reset();

}

public function testSameServerDiffCarriesEveryScriptByteForByte(): void

{

[$source, $target] = $this->fixture('same');

$up = $this->cliUp($source, $target, 'all');

if ($this->onDolt()) {

$this->assertCaseOnlyChangesPlanned($up);

return;

}

$this->apply($target, $up);

$this->assertSame($this->snapshot($source), $this->snapshot($target));

}

/** The streaming merge — the cross-server path — on the same rows. */

public function testStreamingMergeSeesFourByteChanges(): void

{

[$source, $target] = $this->fixture('stream');

$capsule = new Capsule;

$dispatcher = new Dispatcher();

$dispatcher->listen(StatementPrepared::class, fn($e) => $e->statement->setFetchMode(PDO::FETCH_ASSOC));

$capsule->setEventDispatcher($dispatcher);

$conn = [];

foreach ([$source, $target] as $db) {

$capsule->addConnection(['driver' => 'mysql', 'host' => $this->host, 'port' => $this->port, 'database' => $db,

'username' => 'root', 'password' => $this->password, 'charset' => 'utf8mb4', 'collation' => 'utf8mb4_unicode_ci'], $db);

$conn[] = $capsule->getConnection($db);

}

$merge = new StreamingMergeDiff($conn[0], $conn[1], 'mysql');

$dialect = new MySQLDialect();

$up = [];

foreach (['gurbani' => ['id'], 'words' => ['word']] as $table => $key) {

$cols = array_column($this->pdo($source)->query("SHOW COLUMNS FROM `$table`")->fetchAll(PDO::FETCH_ASSOC), 'Field');

foreach ($merge->getDiff($table, $key, $cols, $cols) as $d) {

$sql = match (true) {

$d instanceof InsertData => new InsertDataSQL($d, $dialect),

$d instanceof DeleteData => new DeleteDataSQL($d, $dialect),

default => new UpdateDataSQL($d, $dialect),

};

$up[] = $sql->getUp();

}

}

// Deletes first: a key can come back under another normalisation.

usort($up, fn($a, $b) => str_starts_with($b, 'DELETE') <=> str_starts_with($a, 'DELETE'));

if ($this->onDolt()) {

$this->assertCaseOnlyChangesPlanned(implode("\n", $up));

return;

}

$this->apply($target, implode("\n", $up));

$this->assertSame($this->rows($source), $this->rows($target));

}

public function testThePreScanSeesCollationCommentAndGeneratedChanges(): void

{

$source = $this->db('prescan_s');

$target = $this->db('prescan_t');

$this->pdo($source)->exec("CREATE TABLE c1 (id int PRIMARY KEY, v text COLLATE utf8mb4_unicode_ci);

CREATE TABLE c3 (id int PRIMARY KEY, a int, g int GENERATED ALWAYS AS (a * 2) STORED)");

$this->pdo($target)->exec("CREATE TABLE c1 (id int PRIMARY KEY, v text COLLATE utf8mb4_0900_ai_ci);

CREATE TABLE c3 (id int PRIMARY KEY, a int, g int GENERATED ALWAYS AS (a * 3) STORED)");

$up = $this->cliUp($source, $target, 'schema');

$this->assertMatchesRegularExpression('/ALTER TABLE `c1` CHANGE `v` `v` text .*COLLATE utf8mb4_unicode_ci/', $up);

$this->assertStringContainsString("COMMENT 'ਮੂਲ ਮੰਤਰ'", $up);

// Dolt leaves information_schema's GENERATION_EXPRESSION empty, so

// the pre-scan cannot see this one there; MySQL fills it in.

if (!$this->onDolt()) {

$this->assertMatchesRegularExpression('/ALTER TABLE `c3` CHANGE `g` `g` int GENERATED ALWAYS AS \(\(`a` \* 2\)\)/', $up);

}

}

// ── helpers ──────────────────────────────────────────────────────────────

/**

private function onDolt(): bool

{

try {

$this->admin->query('SELECT dolt_version()');

return true;

} catch (PDOException) {

return false;

}

}

private function assertCaseOnlyChangesPlanned(string $up): void

{

$this->assertStringContainsString("`translit` = 'Akaal Moorat'", $up);

$this->assertStringContainsString("`meaning` = 'wondrous'", $up);

$this->assertStringContainsString("`emoji` = '🎵'", $up);

$this->assertStringContainsString("`emoji` = '𑀅𑀓'", $up);

}

/** Two databases, the target differing in ways only exact bytes reveal. @return string[] */

private function fixture(string $case): array

{

$source = $this->db("uni_{$case}_s");

$target = $this->db("uni_{$case}_t");

$nfd = "cafe\u{0301}"; // é as e + combining acute: looks the same, different bytes

$this->pdo($source)->exec(self::TABLE . ';' . self::WORDS . ";

INSERT INTO words VALUES ('ਸਤਿ','truth'),('ਨਾਮੁ','name'),('Waheguru','wondrous'),('10','ten'),('9','nine'),('é','NFC');");

$this->pdo($target)->exec(self::TABLE . ';' . self::WORDS . ";

INSERT INTO words VALUES ('ਸਤਿ','truth'),('Waheguru','Wondrous'),('9','nine'),('e\u{0301}','NFD'),('ਗੁਰੂ','guru');");

return [$source, $target];

}

private function db(string $name): string

{

$db = "dbdiff_$name";

$this->admin->exec("DROP DATABASE IF EXISTS `$db`");

$this->admin->exec("CREATE DATABASE `$db` CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci");

$this->created[] = $db;

return $db;

}

private function pdo(string $db): PDO

{

return new PDO("mysql:host={$this->host};port={$this->port};dbname=$db;charset=utf8mb4", 'root', $this->password,

[PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);

}

/** The CLI's UP from `$source` to `$target`. */

private function cliUp(string $source, string $target, string $type): string

{

$out = tempnam(sys_get_temp_dir(), 'dbdiff_uni_') . '.sql';

$url = fn($db) => "mysql://root:" . rawurlencode($this->password) . "@{$this->host}:{$this->port}/$db";

exec(escapeshellarg(PHP_BINARY) . ' ' . escapeshellarg(dirname(__DIR__, 2) . '/dbdiff.php')

. " diff --type=$type --include=up --nocomments --allow-destructive"

. ' --server1-url=' . escapeshellarg($url($source)) . ' --server2-url=' . escapeshellarg($url($target))

. ' --output=' . escapeshellarg($out) . ' 2>&1', $log, $status);

$this->assertSame(0, $status, implode("\n", $log));

$sql = file_exists($out) ? file_get_contents($out) : '';

@unlink($out);

return $sql;

}

private function apply(string $db, string $sql): void

{

$pdo = $this->pdo($db);

foreach (preg_split('/;\s*$/m', preg_replace('/^--.*$/m', '', $sql)) as $statement) {

if (trim($statement) !== '') {

$pdo->exec($statement);

}

}

}

/** Every value as hex, so a byte that changed cannot hide behind a collation. */

private function rows(string $db): array

{

$pdo = $this->pdo($db);

return [

$pdo->query("SELECT CONCAT_WS('|', id, HEX(gurmukhi), HEX(translit), HEX(english), HEX(other), HEX(emoji), HEX(legacy)) FROM gurbani ORDER BY id")->fetchAll(PDO::FETCH_COLUMN),

$pdo->query("SELECT CONCAT_WS('|', HEX(word), HEX(meaning)) FROM words ORDER BY HEX(word)")->fetchAll(PDO::FETCH_COLUMN),

];

}

private function snapshot(string $db): array

{

$collations = $this->admin->query("SELECT CONCAT_WS(' ', TABLE_NAME, COLUMN_NAME, IFNULL(COLLATION_NAME, ''))

FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '$db' ORDER BY 1")->fetchAll(PDO::FETCH_COLUMN);

return [$this->rows($db), $collations];

}