Fix: no-useless-return stack overflow on loops after throw (fixes #7855…

…) (#7856)
eslint · Jan 5, 2017 · ca1f841 · ca1f841
1 parent d80d994
commit ca1f841
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Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/lib/rules/no-useless-return.js b/lib/rules/no-useless-return.js
@@ -120,15 +120,23 @@ module.exports = {
          *
          * @param {ASTNode[]} uselessReturns - The collected return statements.
          * @param {CodePathSegment[]} prevSegments - The previous segments to traverse.
+         * @param {WeakSet<CodePathSegment>} [traversedSegments] A set of segments that have already been traversed in this call
          * @returns {ASTNode[]} `uselessReturns`.
          */
-        function getUselessReturns(uselessReturns, prevSegments) {
+        function getUselessReturns(uselessReturns, prevSegments, traversedSegments) {
+            if (!traversedSegments) {
+                traversedSegments = new WeakSet();
+            }
             for (const segment of prevSegments) {
                 if (!segment.reachable) {
-                    getUselessReturns(
-                        uselessReturns,
-                        segment.allPrevSegments.filter(isReturned)
-                    );
+                    if (!traversedSegments.has(segment)) {
+                        traversedSegments.add(segment);
+                        getUselessReturns(
+                            uselessReturns,
+                            segment.allPrevSegments.filter(isReturned),
+                            traversedSegments
+                        );
+                    }
                     continue;
                 }
 

diff --git a/tests/lib/rules/no-useless-return.js b/tests/lib/rules/no-useless-return.js
@@ -157,6 +157,14 @@ ruleTester.run("no-useless-return", rule, {
             while (foo) return;
             foo;
           }
+        `,
+
+        // https://github.com/eslint/eslint/issues/7855
+        `
+          try {
+            throw new Error('foo');
+            while (false);
+          } catch (err) {}
         `
     ],