Feat. New option ignoreFunction according to issue#32

README.md

@@ -105,6 +105,15 @@ This option is to signal `serialize()` that we want to do a straight conversion,
 serialize(obj, {unsafe: true});
 ```
 
+#### `options.ignoreFunction`
+
+This option is to signal `serialize()` that we do not want serialize JavaScript function. 
+Just treat function like `JSON.stringify` do, but other features will work as expected.
+
+```js
+serialize(obj, {ignoreFunction: true});
+```
+
 ## Deserializing
 
 For some use cases you might also need to deserialize the string. This is explicitly not part of this module. However, you can easily write it yourself:

index.js

@@ -31,6 +31,18 @@ function escapeUnsafeChars(unsafeChar) {
     return ESCAPED_CHARS[unsafeChar];
 }
 
+function deleteFunctions(obj){
+    var functionKeys = [];
+    for (var key in obj) {
+        if (typeof obj[key] === "function") {
+            functionKeys.push(key);
+        }
+    }
+    for (var i = 0; i < functionKeys.length; i++) {
+        delete obj[functionKeys[i]];
+    }
+}
+
 module.exports = function serialize(obj, options) {
     options || (options = {});
 
@@ -50,6 +62,11 @@ module.exports = function serialize(obj, options) {
     // which are later replaced by their string representation.
     function replacer(key, value) {
 
+        // For nested function
+        if(options.ignoreFunction){
+            deleteFunctions(value);
+        }
+
         if (!value && value !== undefined) {
             return value;
         }
@@ -125,6 +142,10 @@ module.exports = function serialize(obj, options) {
       return serializedFn;
     }
 
+    // Check if the parameter is function
+    if (options.ignoreFunction && typeof obj === "function") {
+        obj = undefined;
+    }
     // Protects against `JSON.stringify()` returning `undefined`, by serializing
     // to the literal string: "undefined".
     if (obj === undefined) {

test/unit/serialize.js

@@ -424,6 +424,29 @@ describe('serialize( obj )', function () {
             expect(serialize(["<"], {space: 2})).to.equal('[\n  "\\u003C"\n]');
             expect(serialize(["<"], {unsafe: true, space: 2})).to.equal('[\n  "<"\n]');
         });
+
+        it("should accept a `ignoreFunction` option", function() {
+            function fn() { return true; }
+            var obj = {
+                fn: fn,
+                fn_arrow: () => {
+                    return true;
+                }
+            };            
+            var obj2 = {
+                num: 123,
+                str: 'str',
+                fn: fn
+            }
+            // case 1. Pass function to serialize
+            expect(serialize(fn, { ignoreFunction: true })).to.equal('undefined');
+            // case 2. Pass function(arrow) in object to serialze
+            expect(serialize(obj, { ignoreFunction: true })).to.equal('{}');
+            // case 3. Other features should work
+            expect(serialize(obj2, { ignoreFunction: true })).to.equal(
+              '{"num":123,"str":"str"}'
+            );
+        });
     });
 
     describe('backwards-compatability', function () {