Remove TwigExtension setter methods - use constructor instead

Is this still needed? Constructor injection requires more to mock when PHPUnit testing.

This would currently be 4 new constructor parameters and more if we add more services providing twig filters and functions.

The change is a nice cleanup/standardization.

Unless there is a specific reason it is better to be more tightly constrained - inject at the point of construction and be done with it .. rather than allow the dependencies to be set dynamically.

I have visually scanned the patch ... all changes make sense.

I'm +1 for this now talking to @laurii and @xano because it makes sense that all of our deps are not optional.

+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -27,25 +22,73 @@
+   * The service under testing.

this is 'system' under testing not 'service' as an acronym but maybe this could be a spelled out variable? The typo can be changed on commit if it's ok to keep that variable name.

+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -58,63 +58,18 @@ class TwigExtension extends \Twig_Extension {
-  public function setGenerators(UrlGeneratorInterface $url_generator) {
...
-  public function setUrlGenerator(UrlGeneratorInterface $url_generator) {
...
-  public function setThemeManager(ThemeManagerInterface $theme_manager) {
...
-  public function setDateFormatter(DateFormatterInterface $date_formatter) {

I don't think we can remove these in Drupal 8. The rest of the patch looks fine for D8 - we've agreed that constructors can change in minor versions.

Thanks for the changes @lauriii and review @alexpott

+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -27,25 +22,73 @@
+  /**
+   * The service under testing.
+   *
+   * @var \Drupal\Core\Template\TwigExtension
+   */
+  protected $sut;
...
+    $this->sut = new TwigExtension($this->renderer, $this->urlGenerator, $this->themeManager, $this->dateFormatter);

Does sut mean system under test or a service under test? I think we should just be descriptive here. Also the problem here is that system under test and unit testing concepts are tricky to define to together. Looking at http://xunitpatterns.com/SUT.html. The test needs to clearly define what it means by system. But just introducing an acronym makes it more difficult to understand for people. For no reason we are making people have to think "What does sut mean and what does it stand for" when the more valuable considerations are does the test test what it claims to.

The problem isn't the concept of 'system under test' it's just the variable being short. Thanks for trying to resolve @tuutti! I did overhear @lauriii and @alexpott discussing this at the table yesterday at Badcamp, and it just needs a long form name from what I gathered.

Maybe $systemUnderTest?

Lets try again!

...changed code comment to match the variable name.

Thank you for addressing that @tuutti.

Committed dd79f79 and pushed to 8.3.x. Thanks!

diff --git a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
index eb9e650..396b2f9 100644
--- a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -4,8 +4,6 @@
 
 use Drupal\Core\GeneratedLink;
 use Drupal\Core\Render\RenderableInterface;
-use Drupal\Core\Render\RendererInterface;
-use Drupal\Core\Routing\UrlGeneratorInterface;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
 use Drupal\Core\Template\Loader\StringLoader;
 use Drupal\Core\Template\TwigEnvironment;

Unused uses fixed on commit.

diff --git a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
index 3644237..eb9e650 100644
--- a/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -50,7 +50,7 @@ class TwigExtensionTest extends UnitTestCase {
   protected $dateFormatter;
 
   /**
-   * The system under testing.
+   * The system under test.
    *
    * @var \Drupal\Core\Template\TwigExtension
    */

Minor improvement on commit.