Re-add syntax highlighting to daily emails and

...ATDC lessons

source/_pages/atdc/9.md

@@ -22,7 +22,7 @@ I've also seen Unit tests that are very tightly coupled to the implementation, s
 
 Based on what you've learned so far, let's write a Unit test that we'd expect to pass:
 
-```php
+```language-php
 <?php
 
 namespace Drupal\Tests\atdc\Unit;
@@ -58,7 +58,7 @@ Update the test to create a mock version of `NodeInterface` instead.
 
 As the mock an instance of `NodeInterface`, it satisfies the assertion and the test passes.
 
-```php
+```language-php
 /** @test */
 public function it_wraps_a_post(): void {
   $node = $this->createMock(NodeInterface::class);
@@ -69,7 +69,7 @@ public function it_wraps_a_post(): void {
 
 Next, add an assertion to ensure the bundle is correct:
 
-```php
+```language-php
 self::assertSame('post', $node->bundle());
 ```
 
@@ -81,7 +81,7 @@ Because you're using a mock, all methods will return `NULL`.
 
 To get this to pass, you need to define what `$this->bundle()` will return:
 
-```php
+```language-php
 $node->method('bundle')->willReturn('post');
 ```
 
@@ -97,7 +97,7 @@ Within the test, instantiate a new `Postwrapper` class that takes the node as an
 
 Then, add an assertion that a `getType()` method should return `post`.
 
-```php
+```language-php
 $wrapper = new PostWrapper($node);
 
 self::assertSame('post', $wrapper->getType());
@@ -105,7 +105,7 @@ self::assertSame('post', $wrapper->getType());
 
 Next, create a `PostWrapper` class with the `getType()` method:
 
-```php
+```language-php
 <?php
 
 namespace Drupal\atdc;
@@ -132,7 +132,7 @@ We've tested that the `PostWrapper` works with post nodes, but let's also ensure
 
 Create a new test that creates a mock node and returns `page` as the bundle:
 
-```php
+```language-php
 /**
  * @test
  * @testdox It can't wrap a page
@@ -153,7 +153,7 @@ Before creating a new `PostWrapper`, assert that an `InvalidArgumentException` s
 
 To fix it, within the constructor for `PostWrapper`, check the bundle and throw the expected Exception if the bundle is not `post`:
 
-```php
+```language-php
 /**
  * @throws \InvalidArgumentException
  */