MDL-50793 mod_book: Update behat tests

mod/book/tests/behat/show_hide_chapters.feature

@@ -11,9 +11,11 @@ Feature: Book activity chapter visibility management
     And the following "users" exist:
       | username | firstname | lastname | email |
       | teacher1 | Teacher | 1 | teacher1@example.com |
+      | student1 | Student | 2 | student1@example.com |
     And the following "course enrolments" exist:
       | user | course | role |
       | teacher1 | C1 | editingteacher |
+      | student1 | C1 | student        |
     And I log in as "teacher1"
     And I am on "Course 1" course homepage with editing mode on
     And I add a "Book" to section "1" and I fill the form with:
@@ -54,8 +56,8 @@ Feature: Book activity chapter visibility management
     And I turn editing mode off
     And I am on "Course 1" course homepage
     And I follow "Test book"
-    Then I should not see "Second chapter" in the "Table of contents" "block"
-    And I should not see "Third chapter" in the "Table of contents" "block"
+    Then the "class" attribute of "a[title='Second chapter']" "css_element" should contain "dimmed_text"
+    And the "class" attribute of "a[title='Third chapter']" "css_element" should contain "dimmed_text"
     And I follow "Next"
     And I should see "Fourth chapter" in the ".book_content" "css_element"
     And I follow "Exit book"
@@ -72,3 +74,9 @@ Feature: Book activity chapter visibility management
     And I follow "Next"
     And I should see "Fourth chapter" in the ".book_content" "css_element"
     And I follow "Exit book"
+    And I log out
+    And I log in as "student1"
+    And I am on "Course 1" course homepage
+    And I follow "Test book"
+    And I should not see "Second chapter" in the "Table of contents" "block"
+    And I should not see "Third chapter" in the "Table of contents" "block"