Add test for markdown rendering

cypress/integration/1-default-editor/preview.spec.js

@@ -0,0 +1,33 @@
+/// <reference types="cypress" />
+
+describe('Preview', () => {
+    beforeEach(() => {
+        cy.visit(__dirname + '/default.html');
+    });
+
+    it('can show a preview of markdown text', () => {
+        cy.get('.EasyMDEContainer').should('be.visible');
+        cy.get('.EasyMDEContainer .editor-preview').should('not.be.visible');
+
+        // Enter markdown text.
+        cy.get('.EasyMDEContainer .CodeMirror').type('# My Big Title');
+        cy.get('.EasyMDEContainer .CodeMirror').type('{enter}');
+        cy.get('.EasyMDEContainer .CodeMirror').type('This is some **important** text!');
+
+        cy.get('.EasyMDEContainer .CodeMirror-line').should('contain', '# My Big Title');
+        cy.get('.EasyMDEContainer .cm-header.cm-header-1').should('contain', '#');
+        cy.get('.EasyMDEContainer .cm-header.cm-header-1').should('contain', 'My Big Title');
+
+        cy.get('.EasyMDEContainer .CodeMirror-line').should('contain', 'This is some **important** text!');
+        cy.get('.EasyMDEContainer .cm-strong').should('contain', '**');
+        cy.get('.EasyMDEContainer .cm-strong').should('contain', 'important');
+
+        // Toggle preview.
+        cy.get('.EasyMDEContainer .editor-toolbar button.preview').click();
+        cy.get('.EasyMDEContainer .editor-preview').should('be.visible');
+
+        // Check preview window for rendered markdown.
+        cy.get('.EasyMDEContainer .editor-preview').should('contain.html', '<h1 id="my-big-title">My Big Title</h1>');
+        cy.get('.EasyMDEContainer .editor-preview').should('contain.html', '<p>This is some <strong>important</strong> text!</p>');
+    });
+});