server: refactor log_interceptor to be more DRY (#9617)

This is purely an internal refactor that should have no effect on consumers of the LogInterceptor class.
elastic · Dec 22, 2016 · aaab285 · aaab285
1 parent 116530a
commit aaab285
Showing 1 changed file with 21 additions and 36 deletions.
diff --git a/src/server/logging/log_interceptor.js b/src/server/logging/log_interceptor.js
@@ -5,6 +5,24 @@ function doTagsMatch(event, tags) {
   return isEqual(get(event, 'tags'), tags);
 }
 
+// converts the given event into a debug log if it's an error of the given type
+function downgradeIfErrorMatches(errorType, event) {
+  const isClientError = doTagsMatch(event, ['connection', 'client', 'error']);
+  const matchesErrorType = isClientError && get(event, 'data.errno') === errorType;
+
+  if (!matchesErrorType) return null;
+
+  const errorTypeTag = errorType.toLowerCase();
+
+  return {
+    event: 'log',
+    pid: event.pid,
+    timestamp: event.timestamp,
+    tags: ['debug', 'connection', errorTypeTag],
+    data: `${errorType}: Socket was closed by the client (probably the browser) before it could be read completely`
+  };
+}
+
 export class LogInterceptor extends Stream.Transform {
   constructor() {
     super({
@@ -24,18 +42,7 @@ export class LogInterceptor extends Stream.Transform {
    *  @param {object} - log event
    */
   downgradeIfEconnreset(event) {
-    const isClientError = doTagsMatch(event, ['connection', 'client', 'error']);
-    const isEconnreset = isClientError && get(event, 'data.errno') === 'ECONNRESET';
-
-    if (!isEconnreset) return null;
-
-    return {
-      event: 'log',
-      pid: event.pid,
-      timestamp: event.timestamp,
-      tags: ['debug', 'connection', 'econnreset'],
-      data: 'ECONNRESET: Socket was closed by the client (probably the browser) before it could be read completely'
-    };
+    return downgradeIfErrorMatches('ECONNRESET', event);
   }
 
   /**
@@ -49,18 +56,7 @@ export class LogInterceptor extends Stream.Transform {
    *  @param {object} - log event
    */
   downgradeIfEpipe(event) {
-    const isClientError = doTagsMatch(event, ['connection', 'client', 'error']);
-    const isEpipe = isClientError && get(event, 'data.errno') === 'EPIPE';
-
-    if (!isEpipe) return null;
-
-    return {
-      event: 'log',
-      pid: event.pid,
-      timestamp: event.timestamp,
-      tags: ['debug', 'connection', 'epipe'],
-      data: 'EPIPE: Socket was closed by the client (probably the browser) before the response could be completed'
-    };
+    return downgradeIfErrorMatches('EPIPE', event);
   }
 
   /**
@@ -74,18 +70,7 @@ export class LogInterceptor extends Stream.Transform {
    *  @param {object} - log event
    */
   downgradeIfEcanceled(event) {
-    const isClientError = doTagsMatch(event, ['connection', 'client', 'error']);
-    const isEcanceled = isClientError && get(event, 'data.errno') === 'ECANCELED';
-
-    if (!isEcanceled) return null;
-
-    return {
-      event: 'log',
-      pid: event.pid,
-      timestamp: event.timestamp,
-      tags: ['debug', 'connection', 'ecanceled'],
-      data: 'ECANCELED: Socket was closed by the client (probably the browser) before the response could be completed'
-    };
+    return downgradeIfErrorMatches('ECANCELED', event);
   }
 
   _transform(event, enc, next) {