Added detection of custom gulp-plumber sanitizer, thus one would not flag such instances.

Author: Napalys

javascript/ql/src/Quality/UnhandledStreamPipe.ql

@@ -188,6 +188,15 @@ predicate hasErrorHandlerRegistered(PipeCall pipeCall) {
     handler = streamRef(pipeCall).getAMethodCall(getEventHandlerMethodName()) and
     handler.getArgument(0).getStringValue() = "error"
   )
+  or
+  hasPlumber(pipeCall)
+}
+
+/**
+ * Holds if one of the arguments of the pipe call is a `gulp-plumber` monkey patch.
+ */
+predicate hasPlumber(PipeCall pipeCall) {
+  streamRef+(pipeCall) = API::moduleImport("gulp-plumber").getACall()
 }
 
 /**

javascript/ql/test/query-tests/Quality/UnhandledStreamPipe/test.expected

@@ -13,5 +13,3 @@
 | test.js:185:5:185:32 | copyStr ... nation) | Stream pipe without error handling on the source stream. Errors won't propagate downstream and may be silently dropped. |
 | test.js:190:17:190:40 | notStre ... itable) | Stream pipe without error handling on the source stream. Errors won't propagate downstream and may be silently dropped. |
 | test.js:195:17:195:40 | notStre ... itable) | Stream pipe without error handling on the source stream. Errors won't propagate downstream and may be silently dropped. |
-| test.js:207:5:207:64 | getStre ... e(dest) | Stream pipe without error handling on the source stream. Errors won't propagate downstream and may be silently dropped. |
-| test.js:212:5:212:56 | getStre ... e(dest) | Stream pipe without error handling on the source stream. Errors won't propagate downstream and may be silently dropped. |

javascript/ql/test/query-tests/Quality/UnhandledStreamPipe/test.js

@@ -204,11 +204,11 @@ function test() {
   }
   {
     const plumber = require('gulp-plumber');
-    getStream().pipe(plumber()).pipe(dest).pipe(dest).pipe(dest); // $SPURIOUS:Alert
+    getStream().pipe(plumber()).pipe(dest).pipe(dest).pipe(dest);
   }
   {
     const plumber = require('gulp-plumber');
     const p = plumber();
-    getStream().pipe(p).pipe(dest).pipe(dest).pipe(dest); // $SPURIOUS:Alert
+    getStream().pipe(p).pipe(dest).pipe(dest).pipe(dest);
   }
 }