Complex classes like Inspector often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Inspector, and based on these observations, apply Extract Interface, too.
| 1 | <?php | ||
| 11 | class Inspector | ||
| 12 | { | ||
| 13 | /** | ||
| 14 | * @var \Throwable | ||
| 15 | */ | ||
| 16 | private $exception; | ||
| 17 | |||
| 18 | /** | ||
| 19 | * @var \Whoops\Exception\FrameCollection | ||
| 20 | */ | ||
| 21 | private $frames; | ||
| 22 | |||
| 23 | /** | ||
| 24 | * @var \Whoops\Exception\Inspector | ||
| 25 | */ | ||
| 26 | private $previousExceptionInspector; | ||
| 27 | |||
| 28 | /** | ||
| 29 | * @var \Throwable[] | ||
| 30 | */ | ||
| 31 | private $previousExceptions; | ||
| 32 | |||
| 33 | /** | ||
| 34 | * @param \Throwable $exception The exception to inspect | ||
| 35 | */ | ||
| 36 | 5 | public function __construct($exception) | |
| 37 |     { | ||
| 38 | 5 | $this->exception = $exception; | |
| 39 | 5 | } | |
| 40 | |||
| 41 | /** | ||
| 42 | * @return \Throwable | ||
| 43 | */ | ||
| 44 | 3 | public function getException() | |
| 45 |     { | ||
| 46 | 3 | return $this->exception; | |
| 47 | } | ||
| 48 | |||
| 49 | /** | ||
| 50 | * @return string | ||
| 51 | */ | ||
| 52 | 2 | public function getExceptionName() | |
| 53 |     { | ||
| 54 | 2 | return get_class($this->exception); | |
| 55 | } | ||
| 56 | |||
| 57 | /** | ||
| 58 | * @return string | ||
| 59 | */ | ||
| 60 | public function getExceptionMessage() | ||
| 61 |     { | ||
| 62 | return $this->extractDocrefUrl($this->exception->getMessage())['message']; | ||
| 63 | } | ||
| 64 | |||
| 65 | /** | ||
| 66 | * @return string[] | ||
| 67 | */ | ||
| 68 | 1 | public function getPreviousExceptionMessages() | |
| 69 |     { | ||
| 70 |         return array_map(function ($prev) { | ||
| 71 | /** @var \Throwable $prev */ | ||
| 72 | 1 | return $this->extractDocrefUrl($prev->getMessage())['message']; | |
| 73 | 1 | }, $this->getPreviousExceptions()); | |
| 74 | } | ||
| 75 | |||
| 76 | /** | ||
| 77 | * @return int[] | ||
| 78 | */ | ||
| 79 | public function getPreviousExceptionCodes() | ||
| 80 |     { | ||
| 81 | 1 |         return array_map(function ($prev) { | |
| 82 | /** @var \Throwable $prev */ | ||
| 83 | 1 | return $prev->getCode(); | |
| 84 | 1 | }, $this->getPreviousExceptions()); | |
| 85 | } | ||
| 86 | |||
| 87 | /** | ||
| 88 | * Returns a url to the php-manual related to the underlying error - when available. | ||
| 89 | * | ||
| 90 | * @return string|null | ||
| 91 | */ | ||
| 92 | public function getExceptionDocrefUrl() | ||
| 93 |     { | ||
| 94 | return $this->extractDocrefUrl($this->exception->getMessage())['url']; | ||
| 95 | } | ||
| 96 | |||
| 97 | private function extractDocrefUrl($message) | ||
| 98 |     { | ||
| 99 | $docref = [ | ||
| 100 | 'message' => $message, | ||
| 101 | 'url' => null, | ||
| 102 | ]; | ||
| 103 | |||
| 104 | // php embbeds urls to the manual into the Exception message with the following ini-settings defined | ||
| 105 | // http://php.net/manual/en/errorfunc.configuration.php#ini.docref-root | ||
| 106 |         if (!ini_get('html_errors') || !ini_get('docref_root')) { | ||
| 107 | return $docref; | ||
| 108 | } | ||
| 109 | |||
| 110 | $pattern = "/\[<a href='([^']+)'>(?:[^<]+)<\/a>\]/"; | ||
| 111 |         if (preg_match($pattern, $message, $matches)) { | ||
| 112 | // -> strip those automatically generated links from the exception message | ||
| 113 | $docref['message'] = preg_replace($pattern, '', $message, 1); | ||
| 114 | $docref['url'] = $matches[1]; | ||
| 115 | } | ||
| 116 | |||
| 117 | return $docref; | ||
| 118 | } | ||
| 119 | |||
| 120 | /** | ||
| 121 | * Does the wrapped Exception has a previous Exception? | ||
| 122 | * @return bool | ||
| 123 | */ | ||
| 124 | 2 | public function hasPreviousException() | |
| 128 | |||
| 129 | /** | ||
| 130 | * Returns an Inspector for a previous Exception, if any. | ||
| 131 | * @todo Clean this up a bit, cache stuff a bit better. | ||
| 132 | * @return Inspector | ||
| 133 | */ | ||
| 134 | 2 | public function getPreviousExceptionInspector() | |
| 135 |     { | ||
| 136 | 2 |         if ($this->previousExceptionInspector === null) { | |
| 146 | |||
| 147 | |||
| 148 | /** | ||
| 149 | * Returns an array of all previous exceptions for this inspector's exception | ||
| 150 | * @return \Throwable[] | ||
| 151 | */ | ||
| 152 | 2 | public function getPreviousExceptions() | |
| 166 | |||
| 167 | /** | ||
| 168 | * Returns an iterator for the inspected exception's | ||
| 169 | * frames. | ||
| 170 | * @return \Whoops\Exception\FrameCollection | ||
| 171 | */ | ||
| 172 | 3 | public function getFrames() | |
| 232 | |||
| 233 | /** | ||
| 234 | * Gets the backtrace from an exception. | ||
| 235 | * | ||
| 236 | * If xdebug is installed | ||
| 237 | * | ||
| 238 | * @param \Throwable $e | ||
| 239 | * @return array | ||
| 240 | */ | ||
| 241 | 1 | protected function getTrace($e) | |
| 242 |     { | ||
| 243 | 1 | $traces = $e->getTrace(); | |
| 244 | |||
| 245 | // Get trace from xdebug if enabled, failure exceptions only trace to the shutdown handler by default | ||
| 246 | 1 |         if (!$e instanceof \ErrorException) { | |
| 247 | 1 | return $traces; | |
| 248 | } | ||
| 249 | |||
| 250 |         if (!Misc::isLevelFatal($e->getSeverity())) { | ||
| 251 | return $traces; | ||
| 252 | } | ||
| 253 | |||
| 254 |         if (!extension_loaded('xdebug') || !function_exists('xdebug_is_enabled') || !xdebug_is_enabled()) { | ||
| 255 | return $traces; | ||
| 256 | } | ||
| 257 | |||
| 258 | // Use xdebug to get the full stack trace and remove the shutdown handler stack trace | ||
| 259 | $stack = array_reverse(xdebug_get_function_stack()); | ||
| 260 | $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS); | ||
| 261 | $traces = array_diff_key($stack, $trace); | ||
| 262 | |||
| 263 | return $traces; | ||
| 264 | } | ||
| 265 | |||
| 266 | /** | ||
| 267 | * Given an exception, generates an array in the format | ||
| 268 | * generated by Exception::getTrace() | ||
| 269 | * @param \Throwable $exception | ||
| 270 | * @return array | ||
| 271 | */ | ||
| 272 | 1 | protected function getFrameFromException($exception) | |
| 283 | |||
| 284 | /** | ||
| 285 | * Given an error, generates an array in the format | ||
| 286 | * generated by ErrorException | ||
| 287 | * @param ErrorException $exception | ||
| 288 | * @return array | ||
| 289 | */ | ||
| 290 | protected function getFrameFromError(ErrorException $exception) | ||
| 299 | |||
| 300 | /** | ||
| 301 | * Determine if the frame can be used to fill in previous frame's missing info | ||
| 302 | * happens for call_user_func and call_user_func_array usages (PHP Bug #44428) | ||
| 303 | * | ||
| 304 | * @param array $frame | ||
| 305 | * @return bool | ||
| 306 | */ | ||
| 307 | 1 | protected function isValidNextFrame(array $frame) | |
| 323 | } | ||
| 324 | 
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: