{

#[DataProvider('providerForDecoding')]

public function testWhenDecodingThenReturnsOriginalValue(string $value, string $expected): void

{

/** @Given a Base62 encoded string */

$encoded = $value;

/** @When decoding the encoded string using Base62 */

$actual = Base62::from(value: $encoded)->decode();

/** @Then the decoded value matches the original payload */

self::assertEquals($expected, $actual);

}

#[DataProvider('providerForEncoding')]

public function testWhenEncodingThenReturnsBase62Representation(string $value, string $expected): void

{

/** @Given a raw string value */

$payload = $value;

/** @When encoding the payload using Base62 */

$actual = Base62::from(value: $payload)->encode();

/** @Then the encoded representation matches the expected Base62 string */

self::assertEquals($expected, $actual);

}

#[DataProvider('providerForRoundTripWithAllZeroBytes')]

public function testWhenRoundTrippingAllZeroBytesThenReturnsOriginalPayload(string $value): void

{

/** @Given a binary payload containing only zero bytes */

$payload = $value;

/** @When round-tripping the payload through encode and decode */

$decoded = Base62::from(value: Base62::from(value: $payload)->encode())->decode();

/** @Then the decoded payload matches the original binary payload */

self::assertEquals($payload, $decoded);

}

public function testWhenDecodingValueWithBackslashThenInvalidDecodingIsThrown(): void

{

/** @Given a payload containing a backslash that is not in the Base62 alphabet */

$payload = '\\A';

/** @Then an InvalidDecoding exception describing the payload should be thrown */

$this->expectException(InvalidDecoding::class);

$this->expectExceptionMessage(sprintf('The value <%s> could not be decoded.', $payload));

/** @When attempting to decode the invalid payload */

Base62::from(value: $payload)->decode();

}

#[DataProvider('providerForRoundTripWithLeadingZeroBytes')]

public function testWhenRoundTrippingPayloadWithLeadingZeroBytesThenReturnsOriginalPayload(string $value): void

{

/** @Given a binary payload with leading zero bytes */

$payload = $value;

/** @When round-tripping the payload through encode and decode */

$decoded = Base62::from(value: Base62::from(value: $payload)->encode())->decode();

/** @Then the decoded payload matches the original binary payload */

self::assertEquals($payload, $decoded);

}

public function testWhenDecodingValueWithCharactersOutsideAlphabetThenInvalidDecodingIsThrown(): void

{

/** @Given a binary payload containing characters outside the Base62 alphabet */

$payload = hex2bin('9850EEEC191BF4FF26F99315CE43B0C8');

/** @Then an InvalidDecoding exception describing the payload should be thrown */

$this->expectException(InvalidDecoding::class);

$this->expectExceptionMessage(sprintf('The value <%s> could not be decoded.', $payload));

/** @When attempting to decode the invalid payload */

Base62::from(value: $payload)->decode();

}

public static function providerForDecoding(): array

{

return [

'Zero value' => ['value' => '0', 'expected' => ''],

'Empty string' => ['value' => '', 'expected' => ''],

'Hello world' => ['value' => 'T8dgcjRGuYUueWht', 'expected' => 'Hello world!'],

'Leading zeros' => ['value' => '000001', 'expected' => hex2bin('000000000001')],

'Two zero bytes' => ['value' => '000', 'expected' => "\x00\x00"],

'Numeric string' => ['value' => '1A0afZkibIAR2O', 'expected' => '1234567890'],

'Single zero byte' => ['value' => '00', 'expected' => "\x00"],

'Single character' => ['value' => '1', 'expected' => "\001"],

'Special characters' => ['value' => 'MjehbVgJedVR', 'expected' => '@#$%^&*()']

];

}

public static function providerForEncoding(): array

{

return [

'Hello world' => ['value' => 'Hello world!', 'expected' => 'T8dgcjRGuYUueWht'],

'Empty string' => ['value' => '', 'expected' => ''],

'Numeric string' => ['value' => '1234567890', 'expected' => '1A0afZkibIAR2O'],

'Special characters' => ['value' => '@#$%^&*()', 'expected' => 'MjehbVgJedVR']

];

}

public static function providerForRoundTripWithAllZeroBytes(): array

{

return [

'Single zero byte' => ['value' => "\x00"],

'Two zero bytes' => ['value' => "\x00\x00"],

'Eight zero bytes' => ['value' => str_repeat("\x00", 8)]

];

}

public static function providerForRoundTripWithLeadingZeroBytes(): array

{

return [

'Leading zero bytes 01' => ['value' => '001jlt60MnKnB9ECKRt4gl'],

'Leading zero bytes 02' => ['value' => hex2bin('07d8e31da269bf28')],

'Leading zero bytes 03' => ['value' => hex2bin('0000010203040506')]

];

}