add new hook test file

platforms/web/lib/useComposerModel.test.tsx

@@ -0,0 +1,110 @@
+/*
+Copyright 2023 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 { RefObject } from 'react';
+import { renderHook, waitFor } from '@testing-library/react';
+
+import * as mockRustModel from '../generated/wysiwyg';
+import { useComposerModel } from './useComposerModel';
+
+describe('useComposerModel', () => {
+    const mockComposer = document.createElement('div');
+    const mockNullRef = { current: null } as RefObject<null>;
+    const mockComposerRef = { current: mockComposer } as RefObject<HTMLElement>;
+
+    beforeEach(() => {
+        vi.spyOn(mockRustModel, 'new_composer_model');
+        vi.spyOn(mockRustModel, 'new_composer_model_from_html');
+    });
+
+    afterEach(() => {
+        vi.clearAllMocks();
+    });
+
+    it('Does not create a composerModel without a ref', () => {
+        const { result } = renderHook(() => useComposerModel(mockNullRef));
+
+        expect(result.current.composerModel).toBeNull();
+    });
+
+    it('Only calls `new_composer_model` if ref exists but no initial content exists', async () => {
+        const { result } = renderHook(() => useComposerModel(mockComposerRef));
+
+        // wait for the composerModel to be created
+        await waitFor(() => {
+            expect(result.current.composerModel).not.toBeNull();
+        });
+
+        // check only new_composer_model has been called
+        expect(mockRustModel.new_composer_model).toHaveBeenCalledTimes(1);
+        expect(
+            mockRustModel.new_composer_model_from_html,
+        ).not.toHaveBeenCalled();
+    });
+
+    it('Calls `new_composer_model_from_html` if ref and initial content exists', async () => {
+        const { result } = renderHook(() =>
+            useComposerModel(mockComposerRef, 'some content'),
+        );
+
+        // wait for the composerModel to be created
+        await waitFor(() => {
+            expect(result.current.composerModel).not.toBeNull();
+        });
+
+        // check only new_composer_model_from_html has been called
+        expect(
+            mockRustModel.new_composer_model_from_html,
+        ).toHaveBeenCalledTimes(1);
+        expect(mockRustModel.new_composer_model).not.toHaveBeenCalled();
+    });
+
+    it('Sets the ref inner html when initial content is valid html', async () => {
+        const inputContent = `<a href="this is allowed" other="disallowedattribute">test link</a>`;
+
+        // the rust model will strip "bad" attributes and the hook always adds a trailing <br>
+        const expectedComposerInnerHtml = `<a href="this is allowed">test link</a><br>`;
+        const { result } = renderHook(() =>
+            useComposerModel(mockComposerRef, inputContent),
+        );
+
+        // wait for the composerModel to be created
+        await waitFor(() => {
+            expect(result.current.composerModel).not.toBeNull();
+        });
+
+        // check that the content of the div is the rust model output
+        expect(mockComposer.innerHTML).toBe(expectedComposerInnerHtml);
+    });
+
+    it('Falls back to calling `new_composer_model` if there is a parsing error', async () => {
+        // Use badly formed initial content to cause a html parsing error
+        const { result } = renderHook(() =>
+            useComposerModel(mockComposerRef, '<badly>formed content</>'),
+        );
+
+        // wait for the composerModel to be created
+        await waitFor(() => {
+            expect(result.current.composerModel).not.toBeNull();
+        });
+
+        // check that both functions have been called
+        expect(
+            mockRustModel.new_composer_model_from_html,
+        ).toHaveBeenCalledTimes(1);
+        expect(mockRustModel.new_composer_model).toHaveBeenCalledTimes(1);
+    });
+});