Cover change username page with e2e tests and fix minor bugs

tests-e2e/cypress/integration/profile/change-username.test.ts

@@ -0,0 +1,92 @@
+describe('Change username', () => {
+  it('should change username', () => {
+    cy.server();
+
+    cy.login({ accounts: ['default'] }).then(({ accounts: [account] }) => {
+      cy.route({
+        method: 'GET',
+        url: `/api/v1/accounts/${account.id}`,
+        response: {
+          id: 7,
+          uuid: '522e8c19-89d8-4a6d-a2ec-72ebb58c2dbe',
+          username: 'FooBar',
+          isOtpEnabled: false,
+          registeredAt: 1475568334,
+          lang: 'en',
+          elyProfileLink: 'http://ely.by/u7',
+          email: 'danilenkos@auroraglobal.com',
+          isActive: true,
+          passwordChangedAt: 1476075696,
+          hasMojangUsernameCollision: true,
+          shouldAcceptRules: false,
+        },
+      });
+
+      cy.route({
+        method: 'POST',
+        url: `/api/v1/accounts/${account.id}/username`,
+      }).as('username');
+
+      cy.visit('/');
+
+      cy.getByTestId('profile-item')
+        .contains('Nickname')
+        .closest('[data-testid="profile-item"]')
+        .getByTestId('profile-action')
+        .click();
+
+      cy.location('pathname').should('eq', '/profile/change-username');
+
+      cy.get('[name=username]').type(`{selectall}${account.username}{enter}`);
+
+      cy.wait('@username')
+        .its('requestBody')
+        .should(
+          'eq',
+          new URLSearchParams({
+            username: account.username,
+            password: '',
+          }).toString(),
+        );
+      cy.getByTestId('password-request-form').should('be.visible');
+
+      // unmock accounts route
+      cy.route({
+        method: 'GET',
+        url: `/api/v1/accounts/${account.id}`,
+      });
+
+      cy.get('[name=password]').type(account.password);
+      cy.getByTestId('password-request-form')
+        .find('[type=submit]')
+        .click();
+
+      cy.wait('@username')
+        .its('requestBody')
+        .should(
+          'eq',
+          new URLSearchParams({
+            username: account.username,
+            password: account.password,
+          }).toString(),
+        );
+
+      cy.location('pathname').should('eq', '/');
+      cy.getByTestId('profile-item').should('contain', account.username);
+      cy.getByTestId('toolbar')
+        .contains(account.username)
+        .click();
+      cy.getByTestId('active-account').should('contain', account.username);
+    });
+  });
+
+  it('should go back to profile', () => {
+    cy.login({ accounts: ['default'] });
+
+    cy.visit('/profile/change-username');
+
+    cy.getByTestId('back-to-profile').click();
+
+    cy.location('pathname').should('eq', '/');
+  });
+});