Fix regression around pasting links (#8537)

* Fix regression around pasting links

* Add tests

test/components/views/rooms/BasicMessageComposer-test.tsx

@@ -0,0 +1,65 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+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 from 'react';
+import { mount, ReactWrapper } from 'enzyme';
+import { MatrixClient, Room } from 'matrix-js-sdk/src/matrix';
+
+import BasicMessageComposer from '../../../../src/components/views/rooms/BasicMessageComposer';
+import * as TestUtils from "../../../test-utils";
+import { MatrixClientPeg } from "../../../../src/MatrixClientPeg";
+import EditorModel from "../../../../src/editor/model";
+import { createPartCreator, createRenderer } from "../../../editor/mock";
+
+describe("BasicMessageComposer", () => {
+    const renderer = createRenderer();
+    const pc = createPartCreator();
+
+    beforeEach(() => {
+        TestUtils.stubClient();
+    });
+
+    it("should allow a user to paste a URL without it being mangled", () => {
+        const model = new EditorModel([], pc, renderer);
+
+        const wrapper = render(model);
+
+        wrapper.find(".mx_BasicMessageComposer_input").simulate("paste", {
+            clipboardData: {
+                getData: type => {
+                    if (type === "text/plain") {
+                        return "https://element.io";
+                    }
+                },
+            },
+        });
+
+        expect(model.parts).toHaveLength(1);
+        expect(model.parts[0].text).toBe("https://element.io");
+    });
+});
+
+function render(model: EditorModel): ReactWrapper {
+    const client: MatrixClient = MatrixClientPeg.get();
+
+    const roomId = '!1234567890:domain';
+    const userId = client.getUserId();
+    const room = new Room(roomId, client, userId);
+
+    return mount((
+        <BasicMessageComposer model={model} room={room} />
+    ));
+}