Updated dependencies and introduced delete option with test

README.md

@@ -153,7 +153,7 @@ Returns the parent of the first matching element.
 
 #### jp.apply(obj, pathExpression, fn)
 
-Runs the supplied function `fn` on each matching element, and replaces each matching element with the return value from the function.  The function accepts the value of the matching element as its only parameter.  Returns matching nodes with their updated values.
+Runs the supplied application function `fn` on each matching element, and replaces each matching element with the return value from the function.  The function accepts the value of the matching element as its only parameter.  Returns matching nodes with their updated values.
 
 
 ```javascript
@@ -166,6 +166,8 @@ var nodes = jp.apply(data, '$..author', function(value) { return value.toUpperCa
 // ]
 ```
 
+If the supplied application function returns the special value `:delete:` the node will be deleted and not updated as is otherwise the default case.
+
 #### jp.parse(pathExpression)
 
 Parse the provided JSONPath expression into path components and their associated operations.

lib/index.js

@@ -2,6 +2,7 @@ var assert = require('assert');
 var dict = require('./dict');
 var Parser = require('./parser');
 var Handlers = require('./handlers');
+var remove = require('lodash.remove');
 
 var JSONPath = function() {
   this.initialize.apply(this, arguments);
@@ -27,6 +28,10 @@ JSONPath.prototype.parent = function(obj, string) {
   return this.value(obj, node.path);
 }
 
+function isObject(obj) {
+  return obj === Object(obj);
+}
+
 JSONPath.prototype.apply = function(obj, string, fn) {
 
   assert.ok(obj instanceof Object, "obj needs to be an object");
@@ -38,11 +43,43 @@ JSONPath.prototype.apply = function(obj, string, fn) {
     return b.path.length - a.path.length;
   });
 
+  function removeFromParent(parent, val) {
+    if (!isObject(val)) return;
+    if (!val.remove) return;
+
+    if (typeof val.remove !== 'function') {
+      if (!isObject(val.remove)) return;
+
+      // key: 'id'
+      // match: v.id
+
+      var key = val.remove.key;
+      var match = val.remove.match;
+
+      val.remove = function(obj) {
+        return obj[key] === match;
+      }
+    }
+
+    // use special remove function to remove this node from parent Array
+    remove(parent, val.remove)
+  }
+
   nodes.forEach(function(node) {
     var key = node.path.pop();
     var parent = this.value(obj, this.stringify(node.path));
     var val = node.value = fn.call(obj, parent[key]);
-    parent[key] = val;
+
+    if (Array.isArray(parent)) {
+      removeFromParent(parent, val)
+    } else {
+      // parent must be an Object
+      if (val === ':delete:') {
+        delete parent[key];
+      } else {
+        parent[key] = val;
+      }
+    }
   }, this);
 
   return nodes;

package.json

@@ -1,18 +1,20 @@
 {
   "name": "jsonpath",
   "description": "Query JavaScript objects with JSONPath expressions. Robust / safe JSONPath engine for Node.js.",
-  "version": "0.2.7",
+  "version": "0.2.8",
   "author": "david@fmail.co.uk",
   "scripts": {
     "postinstall": "node lib/aesprim.js > generated/aesprim-browser.js",
     "test": "mocha -u tdd test && jscs lib && jshint lib",
     "generate": "node bin/generate_parser.js > generated/parser.js"
   },
   "dependencies": {
-    "esprima": "1.2.2",
-    "jison": "0.4.13",
-    "static-eval": "0.2.3",
-    "underscore": "1.7.0"
+    "esprima": "^2.0.0",
+    "jison": "^0.4.17",
+    "lodash.filter": "^4.6.0",
+    "lodash.remove": "^4.7.0",
+    "static-eval": "^1.1.1",
+    "underscore": "^1.8.3"
   },
   "browser": {
     "./lib/aesprim.js": "./generated/aesprim-browser.js"
@@ -24,7 +26,7 @@
     "grunt-contrib-uglify": "0.9.1",
     "jscs": "1.10.0",
     "jshint": "2.6.0",
-    "mocha": "2.1.0"
+    "mocha": "^3.1.0"
   },
   "repository": {
     "type": "git",

test/sugar.js

@@ -17,6 +17,65 @@ suite('sugar', function() {
     assert.equal(data.z.a, 101);
   });
 
+  test('apply method deletes value', function() {
+    var data = { a: 1, b: 2, c: 3, z: { a: 100, b: 200 } };
+    jp.apply(data, '$..a', function(v) { return ':delete:' });
+    assert.ok(Object.keys(data).indexOf('a') < 0);
+  });
+
+  test('apply method deletes object from Array specified by remove function', function() {
+    var data = {
+      a: [
+        {
+          id: 'book',
+          price: 100
+        },
+        {
+          id: 'car',
+          price: 3456
+        }
+      ],
+      b: 2
+    };
+
+    jp.apply(data, '$..a[0]', function(v) { 
+      return {
+        remove: (obj) => {
+          return obj.id === v.id;
+        }
+      }
+    });
+
+    assert.equal(data.a[0].id, 'car');
+  });
+
+  test('apply method deletes object from Array specified by special remove object', function() {
+    var data = {
+      a: [
+        {
+          id: 'book',
+          price: 100
+        },
+        {
+          id: 'car',
+          price: 3456
+        }
+      ],
+      b: 2
+    };
+
+    jp.apply(data, '$..a[0]', function(v) { 
+      return {
+        remove: {
+          key: 'id',
+          match: v.id
+        }
+      }
+    });
+
+    assert.equal(data.a[0].id, 'car');
+  });
+
   test('apply method applies survives structural changes', function() {
     var data = {a: {b: [1, {c: [2,3]}]}};
     jp.apply(data, '$..*[?(@.length > 1)]', function(array) {