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:
1 | <?php |
||
23 | class Client |
||
24 | { |
||
25 | const DEFAULT_OPTIONS = [ |
||
26 | Options::SCHEMA => 'https', |
||
27 | Options::PATH => '/', |
||
28 | Options::USER_AGENT => 'WyriHaximus/php-api-client', |
||
29 | Options::HEADERS => [], |
||
30 | ]; |
||
31 | |||
32 | /** |
||
33 | * @var GuzzleClient |
||
34 | */ |
||
35 | protected $handler; |
||
36 | |||
37 | /** |
||
38 | * @var LoopInterface |
||
39 | */ |
||
40 | protected $loop; |
||
41 | |||
42 | /** |
||
43 | * @var array |
||
44 | */ |
||
45 | protected $options = []; |
||
46 | |||
47 | /** |
||
48 | * @var Hydrator |
||
49 | */ |
||
50 | protected $hydrator; |
||
51 | |||
52 | /** |
||
53 | * @var CacheInterface |
||
54 | */ |
||
55 | protected $cache; |
||
56 | |||
57 | /** |
||
58 | * @param LoopInterface $loop |
||
59 | * @param GuzzleClient $handler |
||
60 | * @param array $options |
||
61 | */ |
||
62 | 12 | public function __construct(LoopInterface $loop, GuzzleClient $handler, array $options = []) |
|
72 | |||
73 | /** |
||
74 | * @return Hydrator |
||
75 | */ |
||
76 | 12 | protected function determineHydrator(): Hydrator |
|
84 | |||
85 | /** |
||
86 | * @param string $path |
||
87 | * @param bool $refresh |
||
88 | * @return PromiseInterface |
||
89 | */ |
||
90 | 5 | public function request(string $path, bool $refresh = false): PromiseInterface |
|
96 | |||
97 | /** |
||
98 | * @param string $path |
||
99 | * @param bool $refresh |
||
100 | * @return PromiseInterface |
||
101 | */ |
||
102 | 5 | public function requestRaw(string $path, bool $refresh = false): PromiseInterface |
|
111 | |||
112 | /** |
||
113 | * @param UriInterface $uri |
||
114 | * @return PromiseInterface |
||
115 | */ |
||
116 | 3 | protected function checkCache(UriInterface $uri): PromiseInterface |
|
136 | |||
137 | /** |
||
138 | * @param RequestInterface $request |
||
139 | * @param ResponseInterface $response |
||
140 | */ |
||
141 | 2 | protected function storeCache(RequestInterface $request, ResponseInterface $response) |
|
159 | |||
160 | /** |
||
161 | * @param UriInterface $uri |
||
162 | * @return string |
||
163 | */ |
||
164 | 3 | protected function determineCacheKey(UriInterface $uri): string |
|
179 | |||
180 | /** |
||
181 | * @param string $string |
||
182 | * @return string |
||
183 | */ |
||
184 | 3 | protected function stripExtraSlashes(string $string): string |
|
188 | |||
189 | /** |
||
190 | * @param RequestInterface $request |
||
191 | * @param bool $refresh |
||
192 | * @return PromiseInterface |
||
193 | */ |
||
194 | 5 | public function requestPsr7(RequestInterface $request, bool $refresh = false): PromiseInterface |
|
235 | |||
236 | /** |
||
237 | * @param string $path |
||
238 | * @return RequestInterface |
||
239 | */ |
||
240 | 5 | protected function createRequest(string $path): RequestInterface |
|
246 | |||
247 | /** |
||
248 | * @return array |
||
249 | */ |
||
250 | 5 | public function getHeaders(): array |
|
258 | |||
259 | /** |
||
260 | * @param string $json |
||
261 | * @return PromiseInterface |
||
262 | */ |
||
263 | public function jsonDecode(string $json): PromiseInterface |
||
269 | |||
270 | /** |
||
271 | * @return Hydrator |
||
272 | */ |
||
273 | 1 | public function getHydrator(): Hydrator |
|
277 | |||
278 | /** |
||
279 | * @return LoopInterface |
||
280 | */ |
||
281 | 3 | public function getLoop(): LoopInterface |
|
285 | |||
286 | /** |
||
287 | * @return string |
||
288 | */ |
||
289 | 8 | public function getBaseURL(): string |
|
293 | } |
||
294 |
Let’s assume that you have a directory layout like this:
and let’s assume the following content of
Bar.php
:If both files
OtherDir/Foo.php
andSomeDir/Foo.php
are loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.php
However, as
OtherDir/Foo.php
does not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php
, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: