Merge commit 'be3e8236086165e5e45a5a10783823874b3f3ebd' as 'lib/vscode'

lib/vscode/extensions/markdown-language-features/src/logger.ts

@@ -0,0 +1,87 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { lazy } from './util/lazy';
+
+enum Trace {
+	Off,
+	Verbose
+}
+
+namespace Trace {
+	export function fromString(value: string): Trace {
+		value = value.toLowerCase();
+		switch (value) {
+			case 'off':
+				return Trace.Off;
+			case 'verbose':
+				return Trace.Verbose;
+			default:
+				return Trace.Off;
+		}
+	}
+}
+
+
+function isString(value: any): value is string {
+	return Object.prototype.toString.call(value) === '[object String]';
+}
+
+export class Logger {
+	private trace?: Trace;
+
+	private readonly outputChannel = lazy(() => vscode.window.createOutputChannel('Markdown'));
+
+	constructor() {
+		this.updateConfiguration();
+	}
+
+	public log(message: string, data?: any): void {
+		if (this.trace === Trace.Verbose) {
+			this.appendLine(`[Log - ${this.now()}] ${message}`);
+			if (data) {
+				this.appendLine(Logger.data2String(data));
+			}
+		}
+	}
+
+
+	private now(): string {
+		const now = new Date();
+		return padLeft(now.getUTCHours() + '', 2, '0')
+			+ ':' + padLeft(now.getMinutes() + '', 2, '0')
+			+ ':' + padLeft(now.getUTCSeconds() + '', 2, '0') + '.' + now.getMilliseconds();
+	}
+
+	public updateConfiguration() {
+		this.trace = this.readTrace();
+	}
+
+	private appendLine(value: string) {
+		return this.outputChannel.value.appendLine(value);
+	}
+
+	private readTrace(): Trace {
+		return Trace.fromString(vscode.workspace.getConfiguration().get<string>('markdown.trace', 'off'));
+	}
+
+	private static data2String(data: any): string {
+		if (data instanceof Error) {
+			if (isString(data.stack)) {
+				return data.stack;
+			}
+			return (data as Error).message;
+		}
+		if (isString(data)) {
+			return data;
+		}
+		return JSON.stringify(data, undefined, 2);
+	}
+}
+
+function padLeft(s: string, n: number, pad = ' ') {
+	return pad.repeat(Math.max(0, n - s.length)) + s;
+}