Fix leaks in Login unit tests (#7704)

* make Login-test tsx, fix leaks

Signed-off-by: Kerry Archibald <kerrya@element.io>

* missed lint

Signed-off-by: Kerry Archibald <kerrya@element.io>

test/components/structures/auth/Login-test.tsx

@@ -0,0 +1,158 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React, { Component } from 'react';
+import ReactDOM from 'react-dom';
+import ReactTestUtils from 'react-dom/test-utils';
+import { createClient } from "matrix-js-sdk/src/matrix";
+
+import sdk from '../../../skinned-sdk';
+import SdkConfig from '../../../../src/SdkConfig';
+import { mkServerConfig } from "../../../test-utils";
+
+jest.mock("matrix-js-sdk/src/matrix");
+
+const flushPromises = async () => await new Promise(process.nextTick);
+
+jest.useRealTimers();
+
+const Login = sdk.getComponent(
+    'structures.auth.Login',
+);
+
+describe('Login', function() {
+    let parentDiv;
+    const mockClient = {
+        login: jest.fn().mockResolvedValue({}),
+        loginFlows: jest.fn(),
+    };
+
+    beforeEach(function() {
+        mockClient.login.mockClear().mockResolvedValue({});
+        mockClient.loginFlows.mockClear().mockResolvedValue({ flows: [{ type: "m.login.password" }] });
+        createClient.mockReturnValue(mockClient);
+
+        parentDiv = document.createElement('div');
+        document.body.appendChild(parentDiv);
+    });
+
+    afterEach(function() {
+        ReactDOM.unmountComponentAtNode(parentDiv);
+        parentDiv.remove();
+    });
+
+    function render() {
+        return ReactDOM.render(<Login
+            serverConfig={mkServerConfig("https://matrix.org", "https://vector.im")}
+            onLoggedIn={() => { }}
+            onRegisterClick={() => { }}
+            onServerConfigChange={() => { }}
+        />, parentDiv) as unknown as Component<any, any, any>;
+    }
+
+    it('should show form with change server link', async () => {
+        const root = render();
+
+        await flushPromises();
+
+        const form = ReactTestUtils.findRenderedComponentWithType(
+            root,
+            sdk.getComponent('auth.PasswordLogin'),
+        );
+        expect(form).toBeTruthy();
+
+        const changeServerLink = ReactTestUtils.findRenderedDOMComponentWithClass(root, 'mx_ServerPicker_change');
+        expect(changeServerLink).toBeTruthy();
+    });
+
+    it('should show form without change server link when custom URLs disabled', async () => {
+        jest.spyOn(SdkConfig, "get").mockReturnValue({
+            disable_custom_urls: true,
+        });
+
+        const root = render();
+        await flushPromises();
+
+        const form = ReactTestUtils.findRenderedComponentWithType(
+            root,
+            sdk.getComponent('auth.PasswordLogin'),
+        );
+        expect(form).toBeTruthy();
+
+        const changeServerLinks = ReactTestUtils.scryRenderedDOMComponentsWithClass(root, 'mx_ServerPicker_change');
+        expect(changeServerLinks).toHaveLength(0);
+    });
+
+    it("should show SSO button if that flow is available", async () => {
+        jest.spyOn(SdkConfig, "get").mockReturnValue({
+            disable_custom_urls: true,
+        });
+
+        mockClient.loginFlows.mockReturnValue({ flows: [{ type: "m.login.sso" }] });
+
+        const root = render();
+        await flushPromises();
+
+        const ssoButton = ReactTestUtils.findRenderedDOMComponentWithClass(root, "mx_SSOButton");
+        expect(ssoButton).toBeTruthy();
+    });
+
+    it("should show both SSO button and username+password if both are available", async () => {
+        jest.spyOn(SdkConfig, "get").mockReturnValue({
+            disable_custom_urls: true,
+        });
+
+        mockClient.loginFlows.mockReturnValue({ flows: [{ type: "m.login.password" }, { type: "m.login.sso" }] });
+
+        const root = render();
+        await flushPromises();
+
+        const form = ReactTestUtils.findRenderedComponentWithType(root, sdk.getComponent('auth.PasswordLogin'));
+        expect(form).toBeTruthy();
+
+        const ssoButton = ReactTestUtils.findRenderedDOMComponentWithClass(root, "mx_SSOButton");
+        expect(ssoButton).toBeTruthy();
+    });
+
+    it("should show multiple SSO buttons if multiple identity_providers are available", async () => {
+        jest.spyOn(SdkConfig, "get").mockReturnValue({
+            disable_custom_urls: true,
+        });
+
+        mockClient.loginFlows.mockReturnValue({
+            flows: [{
+                "type": "m.login.sso",
+                "identity_providers": [{
+                    id: "a",
+                    name: "Provider 1",
+                }, {
+                    id: "b",
+                    name: "Provider 2",
+                }, {
+                    id: "c",
+                    name: "Provider 3",
+                }],
+            }],
+        });
+
+        const root = render();
+
+        await flushPromises();
+
+        const ssoButtons = ReactTestUtils.scryRenderedDOMComponentsWithClass(root, "mx_SSOButton");
+        expect(ssoButtons.length).toBe(3);
+    });
+});