flag less overly general functions with js/unneeded-defensive-code

erik-krogh · erik-krogh · commit bf518f1c90a0 · 2021-01-20T15:48:12.000+01:00
diff --git a/javascript/ql/src/Expressions/UnneededDefensiveProgramming.ql b/javascript/ql/src/Expressions/UnneededDefensiveProgramming.ql
@@ -51,5 +51,8 @@ where
     or
     // too benign in practice
     e instanceof DefensiveExpressionTest::DefensiveInit
+    or
+    // functions might be written overly general
+    e.getALocalSource() instanceof DataFlow::ParameterNode
   )
 select e, "This guard always evaluates to " + cv + "."
diff --git a/javascript/ql/test/query-tests/Expressions/UnneededDefensiveProgramming/tst.js b/javascript/ql/test/query-tests/Expressions/UnneededDefensiveProgramming/tst.js
@@ -176,4 +176,11 @@
 	u && (u.p, f()); // technically not OK, but it seems like an unlikely pattern
 	u && !u.p; // NOT OK
 	u && !u(); // NOT OK
+
+    
+    function hasCallbacks(success, error) {
+        if (success) success()
+        if (error) error()
+    }
+    hasCallbacks(() => {}, null);
 });

Original file line number	Diff line number	Diff line change
`@@ -51,5 +51,8 @@ where`
`51`	`51`	`or`
`52`	`52`	`// too benign in practice`
`53`	`53`	`e instanceof DefensiveExpressionTest::DefensiveInit`
	`54`	`+ or`
	`55`	`+ // functions might be written overly general`
	`56`	`+ e.getALocalSource() instanceof DataFlow::ParameterNode`
`54`	`57`	`)`
`55`	`58`	`select e, "This guard always evaluates to " + cv + "."`