[Fix] no-danger-with-children: prevent infinite loop

Fixes #1571

Author: ljharb

lib/rules/no-danger-with-children.js

@@ -29,7 +29,7 @@ module.exports = {
      * @param {object} node - ObjectExpression node
      * @param {string} propName - name of the prop to look for
      */
-    function findObjectProp(node, propName) {
+    function findObjectProp(node, propName, seenProps) {
       if (!node.properties) {
         return false;
       }
@@ -39,7 +39,11 @@ module.exports = {
         } else if (prop.type === 'ExperimentalSpreadProperty') {
           const variable = findSpreadVariable(prop.argument.name);
           if (variable && variable.defs.length && variable.defs[0].node.init) {
-            return findObjectProp(variable.defs[0].node.init, propName);
+            if (seenProps.indexOf(prop.argument.name) > -1) {
+              return false;
+            }
+            const newSeenProps = seenProps.concat(prop.argument.name || []);
+            return findObjectProp(variable.defs[0].node.init, propName, newSeenProps);
           }
         }
         return false;
@@ -57,7 +61,7 @@ module.exports = {
         if (attribute.type === 'JSXSpreadAttribute') {
           const variable = findSpreadVariable(attribute.argument.name);
           if (variable && variable.defs.length && variable.defs[0].node.init) {
-            return findObjectProp(variable.defs[0].node.init, propName);
+            return findObjectProp(variable.defs[0].node.init, propName, []);
           }
         }
         return attribute.name && attribute.name.name === propName;
@@ -113,10 +117,10 @@ module.exports = {
             }
           }
 
-          const dangerously = findObjectProp(props, 'dangerouslySetInnerHTML');
+          const dangerously = findObjectProp(props, 'dangerouslySetInnerHTML', []);
 
           if (node.arguments.length === 2) {
-            if (findObjectProp(props, 'children')) {
+            if (findObjectProp(props, 'children', [])) {
               hasChildren = true;
             }
           } else {

tests/lib/rules/no-danger-with-children.js

@@ -91,6 +91,12 @@ ruleTester.run('no-danger-with-children', rule, {
     },
     {
       code: 'React.createElement("Hello", undefined, "Children")'
+    },
+    {
+      code: `
+        const props = {...props, scratch: {mode: 'edit'}};
+        const component = shallow(<TaskEditableTitle {...props} />);
+      `
     }
   ],
   invalid: [