add generic caption typography component (#9283)

res/css/_components.pcss

@@ -38,6 +38,7 @@
 @import "./components/views/settings/devices/_SelectableDeviceTile.pcss";
 @import "./components/views/settings/shared/_SettingsSubsection.pcss";
 @import "./components/views/spaces/_QuickThemeSwitcher.pcss";
+@import "./components/views/typography/_Caption.pcss";
 @import "./structures/_AutoHideScrollbar.pcss";
 @import "./structures/_BackdropPanel.pcss";
 @import "./structures/_CompatibilityPage.pcss";

res/css/components/views/typography/_Caption.pcss

@@ -0,0 +1,20 @@
+/*
+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.
+*/
+
+.mx_Caption {
+    font-size: $font-12px;
+    color: $secondary-content;
+}

src/components/views/typography/Caption.tsx

@@ -0,0 +1,27 @@
+/*
+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, { HTMLAttributes } from 'react';
+
+interface Props extends Omit<HTMLAttributes<HTMLSpanElement>, 'className'> {
+    children: React.ReactNode;
+}
+
+export const Caption: React.FC<Props> = ({ children, ...rest }) => {
+    return <span className='mx_Caption' {...rest}>
+        { children }
+    </span>;
+};

test/components/views/typography/Caption-test.tsx

@@ -0,0 +1,40 @@
+/*
+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 { render } from '@testing-library/react';
+
+import { Caption } from '../../../../src/components/views/typography/Caption';
+
+describe('<Caption />', () => {
+    const defaultProps = {
+        'children': 'test',
+        'data-testid': 'test test id',
+    };
+    const getComponent = (props = {}) =>
+        (<Caption {...defaultProps} {...props} />);
+
+    it('renders plain text children', () => {
+        const { container } = render(getComponent());
+        expect({ container }).toMatchSnapshot();
+    });
+
+    it('renders react children', () => {
+        const children = <>Test <b>test but bold</b></>;
+        const { container } = render(getComponent({ children }));
+        expect({ container }).toMatchSnapshot();
+    });
+});

test/components/views/typography/__snapshots__/Caption-test.tsx.snap

@@ -0,0 +1,30 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`<Caption /> renders plain text children 1`] = `
+Object {
+  "container": <div>
+    <span
+      class="mx_Caption"
+      data-testid="test test id"
+    >
+      test
+    </span>
+  </div>,
+}
+`;
+
+exports[`<Caption /> renders react children 1`] = `
+Object {
+  "container": <div>
+    <span
+      class="mx_Caption"
+      data-testid="test test id"
+    >
+      Test 
+      <b>
+        test but bold
+      </b>
+    </span>
+  </div>,
+}
+`;