JS: Ignore delete expressions in js/missing-await

Author: asgerf

javascript/ql/src/Expressions/MissingAwait.ql

@@ -45,7 +45,8 @@ predicate isBadPromiseContext(Expr expr) {
   or
   exists(UnaryExpr e |
     expr = e.getOperand() and
-    not e instanceof VoidExpr
+    not e instanceof VoidExpr and
+    not e instanceof DeleteExpr
   )
   or
   expr = any(UpdateExpr e).getOperand()

javascript/ql/test/query-tests/Expressions/MissingAwait/MissingAwait.expected

@@ -1,4 +1,3 @@
-| tsTest.ts:4:12:4:19 | cache[x] | Missing await. This value is always a promise. |
 | tst.js:8:9:8:13 | thing | Missing await. The value 'thing' is always a promise. |
 | tst.js:10:9:10:13 | thing | Missing await. The value 'thing' is always a promise. |
 | tst.js:12:15:12:19 | thing | Missing await. The value 'thing' is always a promise. |