# Argument Validation

The arguments passed to the `with()` declaration when setting up an expectation determine the criteria for matching method calls to expectations. Thus, we can setup up many expectations for a single method, each differentiated by the expected arguments. Such argument matching is done on a “best fit” basis. This ensures explicit matches take precedence over generalised matches.

An explicit match is merely where the expected argument and the actual argument are easily equated (i.e. using `===` or `==`). More generalised matches are possible using regular expressions, class hinting and the available generic matchers. The purpose of generalised matchers is to allow arguments be defined in non-explicit terms, e.g. `Mockery::any()` passed to `with()` will match any argument in that position.

Mockery’s generic matchers do not cover all possibilities but offers optional support for the Hamcrest library of matchers. Hamcrest is a PHP port of the similarly named Java library (which has been ported also to Python, Erlang, etc). By using Hamcrest, Mockery does not need to duplicate Hamcrest’s already impressive utility which itself promotes a natural English DSL.

The examples below show Mockery matchers and their Hamcrest equivalent, if there is one. Hamcrest uses functions (no namespacing).

Note

If you don’t wish to use the global Hamcrest functions, they are all exposed through the `\Hamcrest\Matchers` class as well, as static methods. Thus, `identicalTo($arg)` is the same as `\Hamcrest\Matchers::identicalTo($arg)`

The most common matcher is the `with()` matcher:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(1):

It tells mockery that it should receive a call to the `foo` method with the integer `1` as an argument. In cases like this, Mockery first tries to match the arguments using `===` (identical) comparison operator. If the argument is a primitive, and if it fails the identical comparison, Mockery does a fallback to the `==` (equals) comparison operator.

When matching objects as arguments, Mockery only does the strict `===` comparison, which means only the same `$object` will match:

    $object = new stdClass();
    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive("foo")
        ->with($object);

    // Hamcrest equivalent
    $mock->shouldReceive("foo")
        ->with(identicalTo($object));

A different instance of `stdClass` will not match.

Note

The `Mockery\Matcher\MustBe` matcher has been deprecated.

If we need a loose comparison of objects, we can do that using Hamcrest’s `equalTo` matcher:

    $mock->shouldReceive("foo")
        ->with(equalTo(new stdClass));

In cases when we don’t care about the type, or the value of an argument, just that any argument is present, we use `any()`:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive("foo")
        ->with(\Mockery::any());

    // Hamcrest equivalent
    $mock->shouldReceive("foo")
        ->with(anything())

Anything and everything passed in this argument slot is passed unconstrained.

## Validating Types and Resources

The `type()` matcher accepts any string which can be attached to `is_` to form a valid type check.

To match any PHP resource, we could do the following:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive("foo")
        ->with(\Mockery::type('resource'));

    // Hamcrest equivalents
    $mock->shouldReceive("foo")
        ->with(resourceValue());
    $mock->shouldReceive("foo")
        ->with(typeOf('resource'));

It will return a `true` from an `is_resource()` call, if the provided argument to the method is a PHP resource. For example, `\Mockery::type('float')` or Hamcrest’s `floatValue()` and `typeOf('float')` checks use `is_float()`, and `\Mockery::type('callable')` or Hamcrest’s `callable()` uses `is_callable()`.

The `type()` matcher also accepts a class or interface name to be used in an `instanceof` evaluation of the actual argument. Hamcrest uses `anInstanceOf()`.

A full list of the type checkers is available at php.net or browse Hamcrest’s function list in the Hamcrest code.

## Complex Argument Validation

If we want to perform a complex argument validation, the `on()` matcher is invaluable. It accepts a closure (anonymous function) to which the actual argument will be passed.

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive("foo")
        ->with(\Mockery::on(closure));

If the closure evaluates to (i.e. returns) boolean `true` then the argument is assumed to have matched the expectation.

    $mock = \Mockery::mock('MyClass');

    $mock->shouldReceive('foo')
        ->with(\Mockery::on(function ($argument) {
            if ($argument % 2 == 0) {
                return true;
            }
            return false;
        }));

    $mock->foo(4); // matches the expectation
    $mock->foo(3); // throws a NoMatchingExpectationException

Note

There is no Hamcrest version of the `on()` matcher.

We can also perform argument validation by passing a closure to `withArgs()` method. The closure will receive all arguments passed in the call to the expected method and if it evaluates (i.e. returns) to boolean `true`, then the list of arguments is assumed to have matched the expectation:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive("foo")
        ->withArgs(closure);

The closure can also handle optional parameters, so if an optional parameter is missing in the call to the expected method, it doesn’t necessary means that the list of arguments doesn’t match the expectation.

    $closure = function ($odd, $even, $sum = null) {
        $result = ($odd % 2 != 0) && ($even % 2 == 0);
        if (!is_null($sum)) {
            return $result && ($odd + $even == $sum);
        }
        return $result;
    };

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')->withArgs($closure);

    $mock->foo(1, 2); // It matches the expectation: the optional argument is not needed
    $mock->foo(1, 2, 3); // It also matches the expectation: the optional argument pass the validation
    $mock->foo(1, 2, 4); // It doesn't match the expectation: the optional doesn't pass the validation

Note

In previous versions, Mockery’s `with()` would attempt to do a pattern matching against the arguments, attempting to use the argument as a regular expression. Over time this proved to be not such a great idea, so we removed this functionality, and have introduced `Mockery::pattern()` instead.

If we would like to match an argument against a regular expression, we can use the `\Mockery::pattern()`:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::pattern('/^foo/'));

    // Hamcrest equivalent
    $mock->shouldReceive('foo')
        with(matchesPattern('/^foo/'));

The `ducktype()` matcher is an alternative to matching by class type:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::ducktype('foo', 'bar'));

It matches any argument which is an object containing the provided list of methods to call.

Note

There is no Hamcrest version of the `ducktype()` matcher.

## Additional Argument Matchers

The `not()` matcher matches any argument which is not equal or identical to the matcher’s parameter:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::not(2));

    // Hamcrest equivalent
    $mock->shouldReceive('foo')
        ->with(not(2));

`anyOf()` matches any argument which equals any one of the given parameters:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::anyOf(1, 2));

    // Hamcrest equivalent
    $mock->shouldReceive('foo')
        ->with(anyOf(1,2));

`notAnyOf()` matches any argument which is not equal or identical to any of the given parameters:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::notAnyOf(1, 2));

Note

There is no Hamcrest version of the `notAnyOf()` matcher.

`subset()` matches any argument which is any array containing the given array subset:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::subset(array(0 => 'foo')));

This enforces both key naming and values, i.e. both the key and value of each actual element is compared.

Note

There is no Hamcrest version of this functionality, though Hamcrest can check a single entry using `hasEntry()` or `hasKeyValuePair()`.

`contains()` matches any argument which is an array containing the listed values:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::contains(value1, value2));

The naming of keys is ignored.

`hasKey()` matches any argument which is an array containing the given key name:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::hasKey(key));

`hasValue()` matches any argument which is an array containing the given value:

    $mock = \Mockery::mock('MyClass');
    $mock->shouldReceive('foo')
        ->with(\Mockery::hasValue(value));