Merge pull request #106 from hapijs/clone-shallow

Clone, shallow, and stringify

README.md

@@ -23,6 +23,8 @@ Lead Maintainer: [Nathan LaFreniere](https://github.com/nlf)
   * [flatten](#flattenarray-target "flatten")
   * [reach](#reachobj-chain-options "reach")
   * [transform](#transformobj-transform-options "transform")
+  * [shallow](#shallowobj "shallow")
+  * [stringify](#stringifyobj "stringify")
 * [Timer](#timer "Timer")
 * [Bench](#bench "Bench")
 * [Binary Encoding/Decoding](#binary-encodingdecoding "Binary Encoding/Decoding")
@@ -313,6 +315,27 @@ var result = Hoek.transform(source, {
 // }
 ```
 
+### shallow(obj)
+
+Performs a shallow copy by copying the references of all the top level children where:
+- `obj` - the object to be copied.
+
+```javascript
+var shallow = Hoek.shallow({ a: { b: 1 } });
+```
+
+### stringify(obj)
+
+Converts an object to string using the built-in `JSON.stringify()` method with the difference that any errors are caught
+and reported back in the form of the returned string. Used as a shortcut for displaying information to the console (e.g. in
+error message) without the need to worry about invalid conversion.
+
+```javascript
+var a = {};
+a.b = a;
+Hoek.stringify(a);		// Returns '[Cannot display object: Converting circular structure to JSON]'
+```
+
 # Timer
 
 A Timer object. Initializing a new timer object sets the ts to the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.

lib/index.js

@@ -64,7 +64,9 @@ exports.clone = function (obj, seen) {
         for (var i in obj) {
             if (obj.hasOwnProperty(i)) {
                 var descriptor = Object.getOwnPropertyDescriptor(obj, i);
-                if (descriptor.get) {
+                if (descriptor.get ||
+                    descriptor.set) {
+
                     Object.defineProperty(newObj, i, descriptor);
                 }
                 else {
@@ -169,7 +171,7 @@ exports.cloneWithShallow = function (source, keys) {
         return source;
     }
 
-    return internals.shallow(source, keys, function () {
+    return internals.withShallow(source, keys, function () {
 
         return exports.clone(source);
     });
@@ -180,14 +182,14 @@ exports.cloneWithShallow = function (source, keys) {
 
 exports.applyToDefaultsWithShallow = function (defaults, options, keys) {
 
-    return internals.shallow(options, keys, function () {
+    return internals.withShallow(options, keys, function () {
 
         return exports.applyToDefaults(defaults, options);
     });
 };
 
 
-internals.shallow = function (source, keys, clone) {
+internals.withShallow = function (source, keys, clone) {
 
     // Move shallow copy items to storage
 
@@ -631,7 +633,7 @@ exports.assert = function (condition /*, msg1, msg2, msg3 */) {
 
     msgs = msgs.map(function (msg) {
 
-        return typeof msg === 'string' ? msg : msg instanceof Error ? msg.message : JSON.stringify(msg);
+        return typeof msg === 'string' ? msg : msg instanceof Error ? msg.message : exports.stringify(msg);
     });
     throw new Error(msgs.join(' ') || 'Unknown error');
 };
@@ -864,3 +866,27 @@ exports.uniqueFilename = function (path, extension) {
     var name = [Date.now(), process.pid, Crypto.randomBytes(8).toString('hex')].join('-') + extension;
     return Path.join(path, name);
 };
+
+
+exports.stringify = function () {
+
+    try {
+        return JSON.stringify.apply(null, arguments);
+    }
+    catch (err) {
+        return '[Cannot display object: ' + err.message + ']';
+    }
+};
+
+
+exports.shallow = function (source) {
+
+    var target = {};
+    var keys = Object.keys(source);
+    for (var i = 0, il = keys.length; i < il; ++i) {
+        var key = keys[i];
+        target[key] = source[key];
+    }
+
+    return target;
+};

test/index.js

@@ -293,6 +293,54 @@ describe('clone()', function () {
         expect(execCount).to.equal(1);
         done();
     });
+
+    it('clones an object with property getter and setter', function (done) {
+
+        var obj = {
+            _test: 0
+        };
+
+        Object.defineProperty(obj, 'test', {
+            enumerable: true,
+            configurable: true,
+            get: function () {
+
+                return this._test;
+            },
+            set: function (value) {
+
+                this._test = value - 1;
+            }
+        });
+
+        var copy = Hoek.clone(obj);
+        expect(copy.test).to.equal(0);
+        copy.test = 5;
+        expect(copy.test).to.equal(4);
+        done();
+    });
+
+    it('clones an object with only property setter', function (done) {
+
+        var obj = {
+            _test: 0
+        };
+
+        Object.defineProperty(obj, 'test', {
+            enumerable: true,
+            configurable: true,
+            set: function (value) {
+
+                this._test = value - 1;
+            }
+        });
+
+        var copy = Hoek.clone(obj);
+        expect(copy._test).to.equal(0);
+        copy.test = 5;
+        expect(copy._test).to.equal(4);
+        done();
+    });
 });
 
 describe('merge()', function () {
@@ -1897,3 +1945,40 @@ describe('uniqueFilename()', function () {
         done();
     });
 });
+
+describe('stringify()', function (done) {
+
+    it('converts object to string', function (done) {
+
+        var obj = { a: 1 };
+        expect(Hoek.stringify(obj)).to.equal('{"a":1}');
+        done();
+    });
+
+    it('returns error in result string', function (done) {
+
+        var obj = { a: 1 };
+        obj.b = obj;
+        expect(Hoek.stringify(obj)).to.equal('[Cannot display object: Converting circular structure to JSON]');
+        done();
+    });
+});
+
+describe('shallow()', function (done) {
+
+    it('shallow copies an object', function (done) {
+
+        var obj = {
+            a: 5,
+            b: {
+                c: 6
+            }
+        };
+
+        var shallow = Hoek.shallow(obj);
+        expect(shallow).to.not.equal(obj);
+        expect(shallow).to.deep.equal(obj);
+        expect(shallow.b).to.equal(obj.b);
+        done();
+    });
+});