Reduce duplication via UsesFlexibleContext trait

Problem:
Each context that wishes to access the FlexibleContext instance needs to implement gathersContexts. This causes duplication in the codebase, and even more so in projects that leverage Flexible Mink.

Solution:
I added a trait called UsesFlexibleContext that gathers the FlexibleContext instance and makes it available via the $this->flexibleContext property.

features/bootstrap/FeatureContext.php

@@ -8,7 +8,7 @@
 use Behat\Mink\Exception\ExpectationException;
 use features\Extensions\Assertion\AssertionContext;
 use Medology\Behat\GathersContexts;
-use Medology\Behat\Mink\FlexibleContext;
+use Medology\Behat\Mink\UsesFlexibleContext;
 use Medology\Behat\Mink\WebDownloadContext;
 use Medology\Behat\TypeCaster;
 use Medology\Behat\UsesStoreContext;
@@ -19,11 +19,9 @@ class FeatureContext implements Context, GathersContexts
     // Depends
     use AssertionContext;
     use TypeCaster;
+    use UsesFlexibleContext;
     use UsesStoreContext;
 
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
     /** @var WebDownloadContext */
     protected $webDownloadContext;
 
@@ -41,10 +39,6 @@ public function gatherContexts(BeforeScenarioScope $scope)
           );
         }
 
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-
         if (!$this->webDownloadContext = $environment->getContext(WebDownloadContext::class)) {
             throw new RuntimeException('Failed to gather WebDownloadContext');
         }

src/Medology/Behat/CsvContext.php

@@ -3,42 +3,18 @@
 namespace Medology\Behat;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Gherkin\Node\TableNode;
 use Exception;
-use Medology\Behat\Mink\FlexibleContext;
-use RuntimeException;
+use Medology\Behat\Mink\UsesFlexibleContext;
 
 /**
  * Provides functionality for working with CSV data.
  */
-class CsvContext implements Context, GathersContexts
+class CsvContext implements Context
 {
+    use UsesFlexibleContext;
     use UsesStoreContext;
 
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
-
     /**
      * Ensures that the given variable in the store is a CSV containing the given rows.
      * The given rows do not have to contain all columns in the store, but the CSV in the store

src/Medology/Behat/Mink/AlertContext.php

@@ -3,44 +3,20 @@
 namespace Medology\Behat\Mink;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Mink\Driver\Selenium2Driver;
 use Behat\Mink\Exception\ExpectationException;
 use Behat\Mink\Exception\UnsupportedDriverActionException;
-use Medology\Behat\GathersContexts;
 use Medology\Spinner;
-use RuntimeException;
 use WebDriver\Exception\NoAlertOpenError;
 
 /**
  * A context for handling JavaScript alerts. Based on a gist by Benjamin Lazarecki with improvements.
  *
  * @link https://gist.github.com/blazarecki/2888851
  */
-class AlertContext implements Context, GathersContexts
+class AlertContext implements Context
 {
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
+    use UsesFlexibleContext;
 
     /**
      * Clears out any alerts or prompts that may be open.

src/Medology/Behat/Mink/JavaScriptContext.php

@@ -3,39 +3,15 @@
 namespace Medology\Behat\Mink;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Gherkin\Node\TableNode;
 use Behat\Mink\Exception\ExpectationException;
-use Medology\Behat\GathersContexts;
-use RuntimeException;
 
 /**
  * {@inheritdoc}
  */
-class JavaScriptContext implements Context, GathersContexts
+class JavaScriptContext implements Context
 {
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
+    use UsesFlexibleContext;
 
     /**
      * Determines if a javascript variable is set and has a value.

src/Medology/Behat/Mink/ScreenShotContext.php

@@ -3,42 +3,18 @@
 namespace Medology\Behat\Mink;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
 use Behat\Behat\Hook\Scope\AfterStepScope;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Mink\Exception\UnsupportedDriverActionException;
 use Behat\Testwork\Tester\Result\TestResult;
-use Medology\Behat\GathersContexts;
-use RuntimeException;
 
 /**
  * Context for capturing screenshots of the web browser.
  *
  * Note: Only works with Mink drivers that support the getScreenshot() method.
  */
-class ScreenShotContext implements Context, GathersContexts
+class ScreenShotContext implements Context
 {
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
+    use UsesFlexibleContext;
 
     /**
      * Captures a screenshot and saves it to the artifacts directory.

src/Medology/Behat/Mink/TableContext.php

@@ -3,47 +3,23 @@
 namespace Medology\Behat\Mink;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Gherkin\Node\TableNode;
 use Behat\Mink\Element\NodeElement;
 use Behat\Mink\Exception\ElementNotFoundException;
 use Behat\Mink\Exception\ExpectationException;
 use InvalidArgumentException;
-use Medology\Behat\GathersContexts;
 use Medology\Behat\UsesStoreContext;
 use Medology\Spinner;
 use RuntimeException;
 
 /**
  * Class TableContext.
  */
-class TableContext implements Context, GathersContexts
+class TableContext implements Context
 {
+    use UsesFlexibleContext;
     use UsesStoreContext;
 
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
-
     /**
      * Finds a table with a given data-qa-id, name, or id. data-qa-id is given preference and matched exactly, while
      * name and id are matched partially.

src/Medology/Behat/Mink/UsesFlexibleContext.php

@@ -0,0 +1,38 @@
+<?php namespace Medology\Behat\Mink;
+
+use Behat\Behat\Context\Environment\InitializedContextEnvironment;
+use Behat\Behat\Hook\Scope\BeforeScenarioScope;
+use RuntimeException;
+
+/**
+ * Trait that grants access to the FlexibleContext instance via $this->flexibleContext.
+ */
+trait UsesFlexibleContext
+{
+    /** @var FlexibleContext */
+    protected $flexibleContext;
+
+    /**
+     * Gathers the FlexibleContext instance and stores a reference in $this->flexibleContext.
+     *
+     * @param  BeforeScenarioScope $scope
+     * @throws RuntimeException    If the current environment is not initialized.
+     * @return void
+     * @BeforeScenario
+     */
+    public function gatherFlexibleContext(BeforeScenarioScope $scope)
+    {
+        $environment = $scope->getEnvironment();
+
+        if (!($environment instanceof InitializedContextEnvironment)) {
+            throw new RuntimeException(
+                'Expected Environment to be ' . InitializedContextEnvironment::class .
+                ', but got ' . get_class($environment)
+            );
+        }
+
+        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
+            throw new RuntimeException('Failed to gather FlexibleContext');
+        }
+    }
+}

src/Medology/Behat/Mink/WebDownloadContext.php

@@ -3,47 +3,22 @@
 namespace Medology\Behat\Mink;
 
 use Behat\Behat\Context\Context;
-use Behat\Behat\Context\Environment\InitializedContextEnvironment;
-use Behat\Behat\Hook\Scope\BeforeScenarioScope;
 use Behat\Mink\Exception\ElementNotFoundException;
 use Behat\Mink\Exception\ExpectationException;
 use Exception;
-use Medology\Behat\GathersContexts;
 use Medology\Behat\UsesStoreContext;
 use Medology\Spinner;
-use RuntimeException;
 
 /**
  * {@inheritdoc}
  */
-class WebDownloadContext implements Context, GathersContexts
+class WebDownloadContext implements Context
 {
+    use UsesFlexibleContext;
     use UsesStoreContext;
 
     protected static $baseUrlRegExp = '/^((http(s|):[\/]{2}|)([a-zA-Z]+\.|)[a-zA-Z0-9]+\.[a-zA-Z]+(\:[\d]+|)|[a-zA-Z0-9]+)/';
 
-    /** @var FlexibleContext */
-    protected $flexibleContext;
-
-    /**
-     * {@inheritdoc}
-     */
-    public function gatherContexts(BeforeScenarioScope $scope)
-    {
-        $environment = $scope->getEnvironment();
-
-        if (!($environment instanceof InitializedContextEnvironment)) {
-            throw new RuntimeException(
-                'Expected Environment to be ' . InitializedContextEnvironment::class .
-                    ', but got ' . get_class($environment)
-          );
-        }
-
-        if (!$this->flexibleContext = $environment->getContext(FlexibleContext::class)) {
-            throw new RuntimeException('Failed to gather FlexibleContext');
-        }
-    }
-
     /**
      * Downloads the file references by the link and stores the content under the given key in the store.
      *