Behat Loves Mink (Free Definitions from MinkExtension)

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Behat parses scenarios and Mink is really good at browsing the web. If we combine their powers, we could start having steps that look a lot like what we have in search.feature.

            
            11 lines
            
            features/search.feature
        
                                                    ... lines 1 - 5
                            
              Scenario: Search for a word that exists
        
                Given I am on "/"
        
                When I fill in "searchTerm" with "Samsung"
        
                And I press "search_submit"
        
                Then I should see "Samsung Galaxy S II"

For the Background step, we now know we could create a matching definition in FeatureContext and easily use Mink's session object to actually go to that URL. But earlier when we ran this scenario, it worked... so there must already be something tie'ing Behat and Mink together.

Let's see what's happening.

Free Behat Steps

First, in FeatureContext I had you extend MinkContext. Remove that now:

            
            86 lines
            
            features/bootstrap/FeatureContext.php
        
                                                    ... lines 1 - 12
                            
            class FeatureContext implements Context, SnippetAcceptingContext
        
                                                    ... lines 14 - 86

When we run Behat, it needs to know all of the step definition language that's available. You can see that list by passing a -dl to the Behat command:

vendor/bin/behat -dl

This shows the four ls definitions we built. So, Behat opens the FeatureContext class, parses out all of the @Given, @When and @Then annotations, and prints a final list here for our enjoyment.

When we add more step definitions, this list grows. And if we use something that isn't here yet, Behat very politely prints out the function for us in the terminal.

In behat.yml we added this MinkExtension configuration:

            
            12 lines
            
            behat.yml
        
            default:
        
                                                    ... lines 2 - 6
                            
                extensions:
        
                    Behat\MinkExtension:
        
                                                    ... lines 9 - 12

This library ties Behat and Mink together and gives us two cool things. First, it lets us access the Mink Session object inside of FeatureContext. We'll see that soon.

For the second thing, add a new config called suites: and a key under that called default: with a contexts: key. We'll talk about suites later. Under contexts, pass FeatureContext and Behat\MinkExtension\Context\MinkContext:

            
            12 lines
            
            behat.yml
        
            default:
        
                suites:
        
                    default:
        
                        contexts:
        
                            - FeatureContext
        
                            - Behat\MinkExtension\Context\MinkContext
        
                                                    ... lines 7 - 12

Now, Behat will look inside FeatureContext and MinkContext for those definition annotations.

Let's see what that gives us: run behat with the -dl option again:

vendor/bin/behat -dl

Boom! Now we see a huge list! These include definitions for all common web actions, like When I go to or When I fill in "field" with "value". This includes the stuff we're using inside of search.feature:

            
            11 lines
            
            features/search.feature
        
                                                    ... lines 1 - 5
                            
              Scenario: Search for a word that exists
        
                Given I am on "/"
        
                When I fill in "searchTerm" with "Samsung"
        
                And I press "search_submit"
        
                Then I should see "Samsung Galaxy S II"

So that's why that scenario already worked.

Let's take a look at where these come from. I'll use shift+shift and search for MinkContext:

            
            487 lines
            
            vendor/behat/mink-extension/src/Behat/MinkExtension/Context/MinkContext.php
        
                                                    ... lines 1 - 21
                            
            class MinkContext extends RawMinkContext implements TranslatableContext
        
            {
        
                /**
        
                                                    ... lines 25 - 26
                            
                 * @Given /^(?:|I )am on (?:|the )homepage$/
        
                 * @When /^(?:|I )go to (?:|the )homepage$/
        
                 */
        
                public function iAmOnHomepage()
        
                {
        
                    $this->visitPath('/');
        
                }
        
                                                    ... lines 34 - 75
                            
                /**
        
                                                    ... lines 77 - 78
                            
                 * @When /^(?:|I )press "(?P<button>(?:[^"]|\\")*)"$/
        
                 */
        
                public function pressButton($button)
        
                {
        
                    $button = $this->fixStepArgument($button);
        
                    $this->getSession()->getPage()->pressButton($button);
        
                }
        
                                                    ... lines 86 - 485
                            
            }

This looks just like our FeatureContext, but has a bunch of goodies already filled in.

So, why did I use this exact language inside of my scenario originally? Because, I'm lazy, and I knew if I followed the language here, I'd get all this functionality for free. And I'm from the midwest in the US: we love free things.

I'll take off the @javascript line:

11 lines features/search.feature

        
                                                    ... lines 1 - 4
                            
              Scenario: Search for a word that exists
        
                                                    ... lines 7 - 11

Since we don't need JavaScript, and now we should be able to run our search feature. Perfect!

What PHP libraries does this tutorial use?

// composer.json
{
    "require": {
        "php": ">=5.4.0, <7.3.0",
        "symfony/symfony": "^2.7", // v2.7.4
        "twig/twig": "^1.22", // v1.22.1
        "sensio/framework-extra-bundle": "^3.0", // v3.0.16
        "doctrine/doctrine-bundle": "^1.5", // v1.5.1
        "doctrine/orm": "^2.5", // v2.5.1
        "doctrine/doctrine-fixtures-bundle": "^2.2", // v2.2.1
        "behat/symfony2-extension": "^2.0" // v2.0.0
    },
    "require-dev": {
        "behat/mink-extension": "^2.0", // v2.0.1
        "behat/mink-goutte-driver": "^1.1", // v1.1.0
        "behat/mink-selenium2-driver": "^1.2", // v1.2.0
        "phpunit/phpunit": "^4.8" // 4.8.18
    }
}

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Behat Loves Mink (Free Definitions from MinkExtension)

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What PHP libraries does this tutorial use?

	... lines 1 - 5
	Scenario: Search for a word that exists
	Given I am on "/"
	When I fill in "searchTerm" with "Samsung"
	And I press "search_submit"
	Then I should see "Samsung Galaxy S II"

	... lines 1 - 12
	class FeatureContext implements Context, SnippetAcceptingContext
	... lines 14 - 86

	default:
	... lines 2 - 6
	extensions:
	Behat\MinkExtension:
	... lines 9 - 12

	default:
	suites:
	default:
	contexts:
	- FeatureContext
	- Behat\MinkExtension\Context\MinkContext
	... lines 7 - 12

	... lines 1 - 21
	class MinkContext extends RawMinkContext implements TranslatableContext
	{
	/**
	... lines 25 - 26
	* @Given /^(?:\|I )am on (?:\|the )homepage$/
	* @When /^(?:\|I )go to (?:\|the )homepage$/
	*/
	public function iAmOnHomepage()
	{
	$this->visitPath('/');
	}
	... lines 34 - 75
	/**
	... lines 77 - 78
	* @When /^(?:\|I )press "(?P<button>(?:[^"]\|\\")*)"$/
	*/
	public function pressButton($button)
	{
	$button = $this->fixStepArgument($button);
	$this->getSession()->getPage()->pressButton($button);
	}
	... lines 86 - 485
	}

	... lines 1 - 4

	Scenario: Search for a word that exists
	... lines 7 - 11