Move helper functions into DOM (#10051)

* Move helper functions into DOM

* Add tests and comments

src/sql/base/browser/dom.ts

@@ -3,6 +3,44 @@
  *  Licensed under the Source EULA. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import { endsWith } from 'vs/base/common/strings';
+import * as types from 'vs/base/common/types';
+
 export function isHidden(element: HTMLElement): boolean {
 	return element.style.display === 'none';
 }
+
+/**
+ * Converts a size value into its string representation. This will add px to the end unless
+ * it already ends with %. If the size value is undefined it will return the defaultValue as-is.
+ * @param size The size value to convert
+ * @param defaultValue The default value to use if the size is undefined
+ */
+export function convertSize(size: number | string | undefined, defaultValue?: string): string {
+	defaultValue = defaultValue || '';
+	if (types.isUndefinedOrNull(size)) {
+		return defaultValue;
+	}
+	let convertedSize: string = size ? size.toString() : defaultValue;
+	if (!endsWith(convertedSize.toLowerCase(), 'px') && !endsWith(convertedSize.toLowerCase(), '%')) {
+		convertedSize = convertedSize + 'px';
+	}
+	return convertedSize;
+}
+
+/**
+ * Converts a size value into its number representation. Supports px, em and unspecified units. 
+ * @param size The size value to convert
+ */
+export function convertSizeToNumber(size: number | string | undefined): number {
+	if (size && typeof (size) === 'string') {
+		if (endsWith(size.toLowerCase(), 'px')) {
+			return +size.replace('px', '');
+		} else if (endsWith(size.toLowerCase(), 'em')) {
+			return +size.replace('em', '') * 11;
+		}
+	} else if (!size) {
+		return 0;
+	}
+	return +size;
+}

src/sql/base/test/browser/dom.test.ts

@@ -0,0 +1,58 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import { convertSize, convertSizeToNumber } from 'sql/base/browser/dom';
+
+suite('DOM Tests', () => {
+
+	test('Convert size should add px', () => {
+		const expected = '100px';
+		const actual = convertSize(100);
+		assert.equal(expected, actual);
+	});
+
+	test('Convert size should not add px if it already has it', () => {
+		const expected = '100px';
+		const actual = convertSize('100px');
+		assert.equal(expected, actual);
+	});
+
+	test('Convert size should not add px if it is a percent value', () => {
+		const expected = '100%';
+		const actual = convertSize('100%');
+		assert.equal(expected, actual);
+	});
+
+	test('Convert size should return the default value given undefined value', () => {
+		const expected = '200';
+		const actual = convertSize(undefined, '200');
+		assert.equal(expected, actual);
+	});
+
+	test('Convert to number should return size without px', () => {
+		const expected = 200;
+		const actual = convertSizeToNumber('200px');
+		assert.equal(expected, actual);
+	});
+
+	test('Convert to number should return same value if already plain text number', () => {
+		const expected = 200;
+		const actual = convertSizeToNumber('200');
+		assert.equal(expected, actual);
+	});
+
+	test('Convert to number should return same value if already plain number', () => {
+		const expected = 200;
+		const actual = convertSizeToNumber(200);
+		assert.equal(expected, actual);
+	});
+
+	test('Convert to number should return 0 given undefined', () => {
+		const expected = 0;
+		const actual = convertSizeToNumber(undefined);
+		assert.equal(expected, actual);
+	});
+});