phpunitHow to use the willReturnMap method in PHPUnit?

The willReturnMap method in PHPUnit is used to specify a map of arguments to return values when a specific method is called. This is useful for testing methods that take multiple arguments and return different values based on the arguments.

Example

$mock = $this->getMockBuilder(MyClass::class)
    ->setMethods(['myMethod'])
    ->getMock();

$mock->expects($this->any())
    ->method('myMethod')
    ->willReturnMap([
        [1, 2, 3, 'foo'],
        [4, 5, 6, 'bar'],
    ]);

$this->assertEquals('foo', $mock->myMethod(1, 2, 3));
$this->assertEquals('bar', $mock->myMethod(4, 5, 6));

Output example

foo
bar

Code explanation

1. $mock = $this->getMockBuilder(MyClass::class): This creates a mock object of the class MyClass.
2. ->setMethods(['myMethod']): This sets the methods to be mocked. In this case, only the method myMethod is mocked.
3. ->willReturnMap([[1, 2, 3, 'foo'], [4, 5, 6, 'bar']]): This specifies a map of arguments to return values when myMethod is called. In this example, when myMethod is called with arguments 1, 2, 3, it will return foo, and when it is called with arguments 4, 5, 6, it will return bar.
4. $this->assertEquals('foo', $mock->myMethod(1, 2, 3)): This asserts that the return value of myMethod when called with arguments 1, 2, 3 is foo.
5. $this->assertEquals('bar', $mock->myMethod(4, 5, 6)): This asserts that the return value of myMethod when called with arguments 4, 5, 6 is bar.

Helpful links

• PHPUnit Documentation - willReturnMap

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