MDL-75982 tiny_equation: add behat for equation editor

lib/editor/tiny/plugins/equation/tests/behat/equation.feature

@@ -0,0 +1,36 @@
+@editor @editor_tiny @tiny_equation
+Feature: Tiny equation editor
+  To teach maths to students, I need to write equations
+
+  @javascript
+  Scenario: Create an equation using TinyMCE
+    Given I log in as "admin"
+    When I open my profile in edit mode
+    And I set the field "Description" to "<p>Equation test</p>"
+    # Set field on the bottom of page, so equation editor dialogue is visible.
+    And I expand all fieldsets
+    And I set the field "Picture description" to "Test"
+    And I expand all toolbars for the "Description" TinyMCE editor
+    And I click on the "Equation editor" button for the "Description" TinyMCE editor
+    And the "class" attribute of "Edit equation using" "field" should contain "text-ltr"
+    And I set the field "Edit equation using" to " = 1 \div 0"
+    And I click on "\infty" "button"
+    And I click on "Save equation" "button"
+    And I click on "Update profile" "button"
+    And I follow "Profile" in the user menu
+    Then "\infty" "text" should exist
+
+  @javascript
+  Scenario: Edit an equation using TinyMCE
+    Given I log in as "admin"
+    When I open my profile in edit mode
+    And I set the field "Description" to "<p>\( \pi \)</p>"
+    # Set field on the bottom of page, so equation editor dialogue is visible.
+    And I expand all fieldsets
+    And I set the field "Picture description" to "Test"
+    And I expand all toolbars for the "Description" TinyMCE editor
+    And I click on the "Equation editor" button for the "Description" TinyMCE editor
+    And the "class" attribute of "Edit equation using" "field" should contain "text-ltr"
+    Then the field "Edit equation using" matches value " \pi "
+    And I click on "Save equation" "button"
+    And the field "Description" matches value "<p>\( \pi \)</p>"