/**
* @throws InvalidKey When an invalid key is encountered
* @throws InvalidValue When an invalid value is encountered
*/
private static function flattenNestedArray(array $nestedArray, string $prefix = '') : array
{
$flatArray = [];
foreach ($nestedArray as $key => $value) {
if (!is_string($key) && ('' === $prefix || !is_int($key))) {
throw InvalidKey::fromNonNestedKey($key);
}
if ('' !== $prefix) {
$key = $prefix . '[' . $key . ']';
}
if (is_string($value)) {
$flatArray[$key] = $value;
continue;
}
if (is_array($value)) {
$flatArray += self::flattenNestedArray($value, $key);
continue;
}
throw InvalidValue::fromNonNestedValue($value);
}
return $flatArray;
}
public function testFromNonNestedKey()
{
$this->assertSame('Expected string or nested integer key, but "boolean" was provided', InvalidKey::fromNonNestedKey(true)->getMessage());
}
