Add log level and log via connection

actions-languageservice/src/log.ts

@@ -0,0 +1,80 @@
+export enum LogLevel {
+  Debug = 0,
+  Info = 1,
+  Warn = 2,
+  Error = 3
+}
+
+const loggers: Logger[] = [];
+let logLevel = LogLevel.Warn;
+
+export interface Logger {
+  /**
+   * Show an error message.
+   *
+   * @param message The message to show.
+   */
+  error(message: string): void;
+  /**
+   * Show a warning message.
+   *
+   * @param message The message to show.
+   */
+  warn(message: string): void;
+  /**
+   * Show an information message.
+   *
+   * @param message The message to show.
+   */
+  info(message: string): void;
+  /**
+   * Log a message.
+   *
+   * @param message The message to log.
+   */
+  log(message: string): void;
+}
+
+export function registerLogger(l: Logger) {
+  loggers.push(l);
+}
+
+export function setLogLevel(ll: LogLevel) {
+  logLevel = ll;
+}
+
+export function info(message: string): void {
+  if (logLevel > LogLevel.Info) {
+    return;
+  }
+
+  for (const l of loggers) {
+    l.info(message);
+  }
+}
+
+export function warn(message: string): void {
+  if (logLevel > LogLevel.Warn) {
+    return;
+  }
+
+  for (const l of loggers) {
+    l.warn(message);
+  }
+}
+
+export function error(message: string): void {
+  if (logLevel > LogLevel.Error) {
+    return;
+  }
+
+  for (const l of loggers) {
+    l.error(message);
+  }
+}
+
+export function log(message: string): void {
+  for (const l of loggers) {
+    l.log(message);
+  }
+}