Buffer the logging until the hook is ready, will prevent lost logs

lib/appenders/hookio.js

@@ -23,7 +23,7 @@ function deserializeLoggingEvent(loggingEvent) {
   };
 }
 
-function createAppender(hookioOptions) {
+function initHook(hookioOptions) {
   var loggerHook;
   if (hookioOptions.mode === 'master') {
     // Start the master hook, handling the actual logging
@@ -33,11 +33,32 @@ function createAppender(hookioOptions) {
     loggerHook = new Hook(hookioOptions);
   }
   loggerHook.start();
+  return loggerHook;
+}
+
+function getBufferedHook(hook, eventName) {
+  var hookBuffer = [];
+  var hookReady = false;
+  hook.on('hook::ready', function emptyBuffer() {
+    hookBuffer.forEach(function logBufferItem(loggingEvent) {
+      hook.emit(eventName, loggingEvent);
+    })
+    hookReady = true;
+  });
 
-  var loggerEvent = hookioOptions.name + '::log';
   return function log(loggingEvent) {
-    loggerHook.emit(loggerEvent, loggingEvent);
-  };
+    if (hookReady) {
+      hook.emit(eventName, loggingEvent);
+    } else {
+      hookBuffer.push(loggingEvent);
+    }
+  }
+}
+
+function createAppender(hookioOptions) {
+  var loggerHook = initHook(hookioOptions);
+  var loggerEvent = hookioOptions.name + '::log';
+  return getBufferedHook(loggerHook, loggerEvent);
 }
 
 function configure(config) {