| Conditions | 3 | 
| Paths | 3 | 
| Total Lines | 10 | 
| Code Lines | 5 | 
| Lines | 0 | 
| Ratio | 0 % | 
| Changes | 0 | ||
| 1 | <?php  | 
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| 27 | public function validate($value, Constraint $constraint)  | 
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| 28 |     { | 
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| 29 |         if (!$value instanceof ExchangeRateInterface) { | 
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| 30 | throw new UnexpectedTypeException($value, ExchangeRateInterface::class);  | 
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| 31 | }  | 
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| 32 | |||
| 33 |         if ($value->getSourceCurrency() === $value->getTargetCurrency()) { | 
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| 34 | $this->context->buildViolation($constraint->message)->addViolation();  | 
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| 35 | }  | 
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| 36 | }  | 
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| 37 | }  | 
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| 38 | 
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: