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  | 
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| 37 | class WhipTest extends PHPUnit_Framework_TestCase  | 
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| 38 | { | 
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| 39 | /**  | 
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| 40 | * Tests that an invalid source format is rejected.  | 
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| 41 | * @expectedException \InvalidArgumentException  | 
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| 42 | */  | 
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| 43 | public function testInvalidSource()  | 
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| 47 | /**  | 
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| 48 | * Tests that we get back the right IP when there using superglobals.  | 
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| 49 | */  | 
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| 50 | public function testSuperglobal()  | 
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| 56 | |||
| 57 | /**  | 
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| 58 | * Tests that we get back 127.0.0.1 when there is no superglobal information  | 
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| 59 | * at all.  | 
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| 60 | */  | 
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| 61 | public function testEmptySuperglobal()  | 
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| 67 | |||
| 68 | /**  | 
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| 69 | * Helper to get a mocked PSR-7 instance.  | 
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| 70 | *  | 
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| 71 | * @param string $remoteAddr The remote address to mock.  | 
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| 72 | * @param string[][] $headers The headers, in the format expected by Psr-7.  | 
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| 73 | */  | 
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| 74 | private function getHttpMessageMock($remoteAddr, array $headers = array())  | 
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| 86 | /**  | 
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| 87 | * Tests that we can use a PSR-7 ServerRequestInterface compatible class.  | 
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| 88 | */  | 
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| 89 | public function testPsr7Request()  | 
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| 105 | |||
| 106 | /**  | 
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| 107 | * Tests that we get false when no valid IP address could be found.  | 
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| 108 | */  | 
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| 109 | public function testNoAddresFoundDueToBitmask()  | 
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| 115 | |||
| 116 | /**  | 
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| 117 | * Tests the standard REMOTE_ADDR method.  | 
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| 118 | */  | 
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| 119 | public function testRemoteAddrMethod()  | 
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| 125 | |||
| 126 | /**  | 
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| 127 | * Tests that an invalid IPv4 address returns false.  | 
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| 128 | */  | 
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| 129 | public function testInvalidIPv4Address()  | 
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| 135 | |||
| 136 | /**  | 
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| 137 | * Tests a valid IPv6 address.  | 
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| 138 | */  | 
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| 139 | public function testValidIPv6Address()  | 
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| 145 | |||
| 146 | /**  | 
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| 147 | * Tests that we accept whitelisted proxy methods when the IP matches, even  | 
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| 148 | * if the IP listed is a comma separated list.  | 
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| 149 | *  | 
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| 150 | * @dataProvider proxyMethodWhitelistProvider  | 
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| 151 | */  | 
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| 152 | View Code Duplication | public function testValidWhitelistedProxyMethod($remoteAddr)  | 
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| 169 | |||
| 170 | /**  | 
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| 171 | * Repeats the above test twice for ipv4 and ipv6  | 
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| 172 | */  | 
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| 173 | public function proxyMethodWhitelistProvider()  | 
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| 180 | |||
| 181 | /**  | 
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| 182 | * Tests that we accept proxy method based on a whitelisted IP using the  | 
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| 183 | * dashed range notation.  | 
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| 184 | */  | 
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| 185 | View Code Duplication | public function testValidWhitelistedProxyMethodWithDashNotation()  | 
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| 206 | |||
| 207 | /**  | 
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| 208 | * Tests that we accept proxy method based on a whitelisted IP using the  | 
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| 209 | * wildcard asterix notation.  | 
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| 210 | */  | 
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| 211 | View Code Duplication | public function testValidWhitelistedProxyMethodWithWildcardNotation()  | 
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| 232 | |||
| 233 | /**  | 
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| 234 | * Tests that we accept proxy method based on a whitelisted IP using the  | 
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| 235 | * CIDR address notation.  | 
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| 236 | */  | 
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| 237 | View Code Duplication | public function testValidWhitelistedProxyMethodWithCIDRdNotation()  | 
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| 258 | |||
| 259 | /**  | 
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| 260 | * Tests that we get false if there is a valid IP in a proxy header but  | 
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| 261 | * we reject it due to REMOTE_ADDR not being in the whitelist.  | 
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| 262 | */  | 
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| 263 | View Code Duplication | public function testValidIpRejectedDueToWhitelist()  | 
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| 284 | |||
| 285 | /**  | 
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| 286 | * Tests that we reject a proxy listed IPv6 address that does not fall within  | 
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| 287 | * the allowed subnet.  | 
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| 288 | */  | 
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| 289 | public function testIPv6AddressRejectedDueToWhitelist()  | 
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| 307 | |||
| 308 | /**  | 
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| 309 | * Tests that we reject a proxy listed IPv6 address that does not fall within  | 
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| 310 | * the allowed subnet.  | 
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| 311 | */  | 
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| 312 | public function testIPv6AddressFoundInWhitelist()  | 
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| 330 | |||
| 331 | /**  | 
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| 332 | * Test that an IPv4 address is rejected because the whitelist is empty for  | 
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| 333 | * IPv4.  | 
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| 334 | */  | 
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| 335 | public function testIPv4AddressRejectedDueToEmptyWhitelist()  | 
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| 353 | |||
| 354 | /**  | 
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| 355 | * Test that an IPv6 address is rejected because the whitelist is empty for  | 
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| 356 | * IPv6.  | 
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| 357 | */  | 
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| 358 | public function testIPv6AddressRejectedDueToEmptyWhitelist()  | 
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| 376 | |||
| 377 | /**  | 
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| 378 | * Test a custom header with a whitelisted IP.  | 
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| 379 | */  | 
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| 380 | View Code Duplication | public function testCustomHeader()  | 
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| 402 | |||
| 403 | /**  | 
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| 404 | * Test HTTP_X_REAL_IP header.  | 
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| 405 | */  | 
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| 406 | public function testHttpXRealIpHeader()  | 
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| 418 | |||
| 419 | /**  | 
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| 420 | * Tests that if we specify the source array, it overrides any values found  | 
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| 421 | * in the $_SERVER array.  | 
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| 422 | */  | 
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| 423 | View Code Duplication | public function testSourceArrayOverridesServerSuperglobal()  | 
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| 432 | |||
| 433 | /**  | 
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| 434 | * Tests that if we specify the source array through Whip::setSource, the  | 
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| 435 | * class will override any values found in $_SERVER.  | 
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| 436 | */  | 
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| 437 | View Code Duplication | public function testSetSourceArrayOverridesServerSuperglobal()  | 
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| 447 | |||
| 448 | /**  | 
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| 449 | * Tests that we fallback to REMOTE_ADDR if the custom header was not found  | 
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| 450 | */  | 
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| 451 | public function testFallbackToRemoteAddr()  | 
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| 459 | }  | 
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| 460 | 
Instead of super-globals, we recommend to explicitly inject the dependencies of your class. This makes your code less dependent on global state and it becomes generally more testable: