Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Stream 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 Stream, and based on these observations, apply Extract Interface, too.
1 | <?php |
||
15 | class Stream implements StreamInterface |
||
16 | { |
||
17 | use Type; |
||
18 | |||
19 | private $type; |
||
20 | private $spec; |
||
21 | private $values; |
||
22 | |||
23 | 375 | public function __construct(string $type) |
|
29 | |||
30 | 3 | public static function of(string $type, ...$values): self |
|
40 | |||
41 | /** |
||
42 | * {@inheritdoc} |
||
43 | */ |
||
44 | 141 | public function type(): Str |
|
48 | |||
49 | /** |
||
50 | * {@inheritdoc} |
||
51 | */ |
||
52 | 48 | public function size(): int |
|
56 | |||
57 | /** |
||
58 | * {@inheritdoc} |
||
59 | */ |
||
60 | 18 | public function count(): int |
|
64 | |||
65 | /** |
||
66 | * {@inheritdoc} |
||
67 | */ |
||
68 | 135 | public function toPrimitive() |
|
72 | |||
73 | /** |
||
74 | * {@inheritdoc} |
||
75 | */ |
||
76 | 102 | public function current() |
|
80 | |||
81 | /** |
||
82 | * {@inheritdoc} |
||
83 | */ |
||
84 | 72 | public function key() |
|
88 | |||
89 | /** |
||
90 | * {@inheritdoc} |
||
91 | */ |
||
92 | 96 | public function next() |
|
96 | |||
97 | /** |
||
98 | * {@inheritdoc} |
||
99 | */ |
||
100 | 102 | public function rewind() |
|
104 | |||
105 | /** |
||
106 | * {@inheritdoc} |
||
107 | */ |
||
108 | 102 | public function valid() |
|
112 | |||
113 | /** |
||
114 | * {@inheritdoc} |
||
115 | */ |
||
116 | 3 | public function offsetExists($offset): bool |
|
120 | |||
121 | /** |
||
122 | * {@inheritdoc} |
||
123 | */ |
||
124 | 27 | public function offsetGet($offset) |
|
128 | |||
129 | /** |
||
130 | * {@inheritdoc} |
||
131 | */ |
||
132 | 3 | public function offsetSet($offset, $value) |
|
136 | |||
137 | /** |
||
138 | * {@inheritdoc} |
||
139 | */ |
||
140 | 3 | public function offsetUnset($offset) |
|
144 | |||
145 | /** |
||
146 | * {@inheritdoc} |
||
147 | */ |
||
148 | 78 | public function get(int $index) |
|
152 | |||
153 | /** |
||
154 | * {@inheritdoc} |
||
155 | */ |
||
156 | 6 | public function diff(StreamInterface $stream): StreamInterface |
|
167 | |||
168 | /** |
||
169 | * {@inheritdoc} |
||
170 | */ |
||
171 | 3 | public function distinct(): StreamInterface |
|
178 | |||
179 | /** |
||
180 | * {@inheritdoc} |
||
181 | */ |
||
182 | 24 | public function drop(int $size): StreamInterface |
|
189 | |||
190 | /** |
||
191 | * {@inheritdoc} |
||
192 | */ |
||
193 | 3 | public function dropEnd(int $size): StreamInterface |
|
200 | |||
201 | /** |
||
202 | * {@inheritdoc} |
||
203 | */ |
||
204 | 33 | public function equals(StreamInterface $stream): bool |
|
212 | |||
213 | /** |
||
214 | * {@inheritdoc} |
||
215 | */ |
||
216 | 6 | public function filter(callable $predicate): StreamInterface |
|
223 | |||
224 | /** |
||
225 | * {@inheritdoc} |
||
226 | */ |
||
227 | 6 | public function foreach(callable $function): StreamInterface |
|
233 | |||
234 | /** |
||
235 | * {@inheritdoc} |
||
236 | */ |
||
237 | 9 | View Code Duplication | public function groupBy(callable $discriminator): MapInterface |
270 | |||
271 | /** |
||
272 | * {@inheritdoc} |
||
273 | */ |
||
274 | 6 | public function first() |
|
278 | |||
279 | /** |
||
280 | * {@inheritdoc} |
||
281 | */ |
||
282 | 6 | public function last() |
|
286 | |||
287 | /** |
||
288 | * {@inheritdoc} |
||
289 | */ |
||
290 | 153 | public function contains($element): bool |
|
294 | |||
295 | /** |
||
296 | * {@inheritdoc} |
||
297 | */ |
||
298 | 57 | public function indexOf($element): int |
|
302 | |||
303 | /** |
||
304 | * {@inheritdoc} |
||
305 | */ |
||
306 | 3 | public function indices(): StreamInterface |
|
313 | |||
314 | /** |
||
315 | * {@inheritdoc} |
||
316 | */ |
||
317 | 9 | public function map(callable $function): StreamInterface |
|
328 | |||
329 | /** |
||
330 | * {@inheritdoc} |
||
331 | */ |
||
332 | 6 | View Code Duplication | public function pad(int $size, $element): StreamInterface |
341 | |||
342 | /** |
||
343 | * {@inheritdoc} |
||
344 | */ |
||
345 | 6 | public function partition(callable $predicate): MapInterface |
|
362 | |||
363 | /** |
||
364 | * {@inheritdoc} |
||
365 | */ |
||
366 | 9 | public function slice(int $from, int $until): StreamInterface |
|
373 | |||
374 | /** |
||
375 | * {@inheritdoc} |
||
376 | */ |
||
377 | 3 | public function splitAt(int $position): StreamInterface |
|
388 | |||
389 | /** |
||
390 | * {@inheritdoc} |
||
391 | */ |
||
392 | 24 | public function take(int $size): StreamInterface |
|
399 | |||
400 | /** |
||
401 | * {@inheritdoc} |
||
402 | */ |
||
403 | 3 | public function takeEnd(int $size): StreamInterface |
|
410 | |||
411 | /** |
||
412 | * {@inheritdoc} |
||
413 | */ |
||
414 | 33 | View Code Duplication | public function append(StreamInterface $stream): StreamInterface |
425 | |||
426 | /** |
||
427 | * {@inheritdoc} |
||
428 | */ |
||
429 | 9 | View Code Duplication | public function intersect(StreamInterface $stream): StreamInterface |
440 | |||
441 | /** |
||
442 | * {@inheritdoc} |
||
443 | */ |
||
444 | 21 | public function join(string $separator): Str |
|
448 | |||
449 | /** |
||
450 | * {@inheritdoc} |
||
451 | */ |
||
452 | 297 | View Code Duplication | public function add($element): StreamInterface |
461 | |||
462 | /** |
||
463 | * {@inheritdoc} |
||
464 | */ |
||
465 | 6 | public function sort(callable $function): StreamInterface |
|
472 | |||
473 | /** |
||
474 | * {@inheritdoc} |
||
475 | */ |
||
476 | 60 | public function reduce($carry, callable $reducer) |
|
480 | |||
481 | /** |
||
482 | * {@inheritdoc} |
||
483 | */ |
||
484 | 45 | public function clear(): StreamInterface |
|
491 | |||
492 | /** |
||
493 | * {@inheritdoc} |
||
494 | */ |
||
495 | 6 | public function reverse(): StreamInterface |
|
502 | |||
503 | /** |
||
504 | * Make sure the stream is compatible with the current one |
||
505 | * |
||
506 | * @param StreamInterface $stream |
||
507 | * |
||
508 | * @throws InvalidArgumentException |
||
509 | * |
||
510 | * @return void |
||
511 | */ |
||
512 | 75 | private function validate(StreamInterface $stream) |
|
520 | } |
||
521 |
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: