Cypress test. Drag canvas. (#3142)

* Cypress test. Drag canvas.

* Added click to ".cvat-move-control"

* Add comment

tests/cypress/integration/actions_tasks3/case_74_drag_canvas.js

@@ -0,0 +1,43 @@
+// Copyright (C) 2021 Intel Corporation
+//
+// SPDX-License-Identifier: MIT
+
+/// <reference types="cypress" />
+
+import { taskName } from '../../support/const';
+
+context('Drag canvas.', () => {
+    const caseId = '74';
+    let topBefore;
+    let leftBefore;
+
+    before(() => {
+        cy.openTaskJob(taskName);
+    });
+
+    describe(`Testing case "${caseId}"`, () => {
+        it('Drag canvas', () => {
+            cy.get('#cvat_canvas_background').invoke('attr', 'style').then(($style) => {
+                topBefore = Number($style.split(';')[0].split(' ')[1].replace('px', ''));
+                leftBefore = Number($style.split(';')[1].split(' ')[2].replace('px', ''));
+            });
+            cy.get('.cvat-move-control').click(); // Without this action, the function is not covered
+            cy.get('.cvat-canvas-container').trigger('mousedown', {button: 0}).trigger('mousemove', 500, 500);
+        });
+
+        it('Top and left style perameters is changed.', () => {
+            cy.get('#cvat_canvas_background').invoke('attr', 'style').then(($style) => {
+                expect(topBefore).not.equal(Number($style.split(';')[0].split(' ')[1].replace('px', ''))); // expected 20 to not equal 95
+                expect(leftBefore).not.equal(Number($style.split(';')[1].split(' ')[2].replace('px', ''))); // expected 73 to not equal 95
+            });
+        });
+
+        it('Duble click on canvas. Parameters returned to their original value', () => {
+            cy.get('.cvat-canvas-container').dblclick();
+            cy.get('#cvat_canvas_background').invoke('attr', 'style').then(($style) => {
+                expect(topBefore).equal(Number($style.split(';')[0].split(' ')[1].replace('px', ''))); // expected 20 to equal 20
+                expect(leftBefore).equal(Number($style.split(';')[1].split(' ')[2].replace('px', ''))); // expected 73 to equal 73
+            });
+        });
+    });
+});