- Fix: Avoid erring when value before parent selector is falsey

brettz9 · brettz9 · commit bc6bca7311f1 · 2020-01-13T12:02:19.000+08:00
diff --git a/CHANGES.md b/CHANGES.md
@@ -4,6 +4,7 @@
 
 - Fix: wrap: false returning inconsistent data types (@CacheControl)
 - Fix: Ensure throwing with a bad result type
+- Fix: Avoid erring when value before parent selector is falsey
 - Enhancement: Allow path as array in non-object signature
 - Linting (ESLint): As per latest ash-nazg
 - Linting (ESLint): Remove redundant "use strict" with switch to ESM
diff --git a/src/jsonpath.js b/src/jsonpath.js
@@ -604,7 +604,7 @@ JSONPath.prototype._trace = function (
     if (this._hasParentSelector) {
         for (let t = 0; t < ret.length; t++) {
             const rett = ret[t];
-            if (rett.isParentSelector) {
+            if (rett && rett.isParentSelector) {
                 const tmp = that._trace(
                     rett.expr, val, rett.path, parent, parentPropName, callback,
                     hasArrExpr
diff --git a/test/test.parent-selector.js b/test/test.parent-selector.js
@@ -36,4 +36,38 @@ describe('JSONPath - Parent selector', function () {
         const result = jsonpath({json, path: 'name^^'});
         assert.deepEqual([], result);
     });
+
+    it('select sibling via parent (with non-match present)', () => {
+        const jsonMultipleChildren = {
+            "name": "root",
+            "children": [
+                {"name": "child1", "children": [{"name": "child1_1"}, {"name": "child1_2"}]},
+                {"name": "child2", "children": [{"name": "child2_1"}]},
+                {"name": "child3", "children": [{"name": "child3_1"}, {"name": "child3_2"}]},
+                {"name": "child4", "children": [{"name": "child4_1"}, {"name": "child3_1"}]}
+            ]
+        };
+        const expected = [{"name": "child3_2"}];
+        const result = jsonpath({
+            json: jsonMultipleChildren,
+            path: '$..[?(@.name && @.name.match(/3_1$/))]^[?(@.name.match(/_2$/))]'
+        });
+        assert.deepEqual(expected, result);
+    });
+    it('select sibling via parent (with multiple results)', () => {
+        const jsonMultipleChildren = {
+            "name": "root",
+            "children": [
+                {"name": "child1", "children": [{"name": "child1_1"}, {"name": "child1_2"}]},
+                {"name": "child2", "children": [{"name": "child2_1"}]},
+                {"name": "child3", "children": [{"name": "child3_1"}, {"name": "child3_2"}, {"name": "child3_2", second: true}]}
+            ]
+        };
+        const expected = [{"name": "child3_2"}, {"name": "child3_2", second: true}];
+        const result = jsonpath({
+            json: jsonMultipleChildren,
+            path: '$..[?(@.name && @.name.match(/3_1$/))]^[?(@.name.match(/_2$/))]'
+        });
+        assert.deepEqual(expected, result);
+    });
 });
