Fixed issue 102

Author: Theo van der Donk

src/jsonpath.js

@@ -790,7 +790,7 @@ JSONPath.toPathArray = function (expr) {
         return !match || !match[1] ? exp : subx[match[1]];
     });
     cache[expr] = exprList;
-    return cache[expr];
+    return cache[expr].concat();
 };
 
 export {JSONPath};

test/test.toPath.js

@@ -46,4 +46,19 @@ describe('JSONPath - toPath*', function () {
 
         assert.strictEqual(path, originalPath);
     });
+
+    it('toPathArray (cache issue)', () => {
+        // We test here a bug where toPathArray did not return a clone of the cached
+        // array. As a result, the evaluate call corrupted the cached value instead
+        // of its local copy.
+        
+        // Make the path unique by including the test name 'cacheissue' in the path
+        // because we do not want it to be in the cache already.
+        const expected = ['$', 'store', 'bicycle', 'cacheissue'];
+        const path = "$.store['bicycle'].cacheissue";
+        const json = {};
+        jsonpath({json, path, wrap: false});
+        const result = jsonpath.toPathArray(path);
+        assert.deepEqual(result, expected);
+    });
 });