From 78969610d7d7f2cb8aae71fbb6667496f1f9e47a Mon Sep 17 00:00:00 2001
From: Zdenko Vujasinovic <zdenko.vujasinovic@gmail.com>
Date: Sat, 24 Feb 2018 18:50:58 +0100
Subject: [PATCH] observable object

---
 main.coffee            | 49 ++++++++++++++++++++++++++++++++
 test/observable.coffee | 63 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 112 insertions(+)

diff --git a/main.coffee b/main.coffee
index 1837a81..aab084f 100644
--- a/main.coffee
+++ b/main.coffee
@@ -146,6 +146,55 @@ module.exports = Observable = (value, context) ->
       size: ->
         magicDependency(self)
         value.length
+  if Object::toString.call(value) is '[object Object]'
+      # proxy object properties and add notifications to mutation events
+      defProp = (property) ->
+        Object.defineProperty self, property,
+          get: ->
+            magicDependency(self)
+            # if object property is Observable, e.g obj = Observable { a: Observable 1 }
+            if typeof value[property]?.observe is "function"
+              value[property]()
+            else
+              value[property]
+          set: (val) ->
+            # if object property is Observable, e.g obj = Observable { a: Observable 1 }
+            if typeof value[property]?.observe is "function"
+              value[property] val
+            else
+              value[property] = val
+              notify value
+
+      defProp prop for own prop of value
+
+      # Proxy object methods, e.g. Object.keys(obj)
+      [
+        "keys"
+        "values"
+        "entries"
+      ].forEach (method) ->
+        Object.defineProperty self, method,
+          get: ->
+            magicDependency(self)
+            Object[method] value
+
+      # Extra methods for object observables
+      extend self,
+        # Remove an element from the object and notify observers of changes.
+        remove: (object) ->
+          if returnValue = value[object]
+            delete value[object]
+            notify(value)
+            return returnValue
+
+        extend: (obj) ->
+          magicDependency(self)
+          value = Object.assign {}, value, obj
+          defProp prop for own prop of obj
+          notify value
+
+      # alias
+      self.assign = self.extend
 
   extend self,
     listeners: listeners
diff --git a/test/observable.coffee b/test/observable.coffee
index b416190..1d1cb6d 100644
--- a/test/observable.coffee
+++ b/test/observable.coffee
@@ -413,3 +413,66 @@ describe "Observable functions", ->
       done()
 
     model.lastName "Bro"
+
+describe "Observable object", ->
+  it "should proxy properties", ->
+    obj = Observable
+      a: 1
+
+    assert.equal obj.a, 1
+    assert.equal obj().a, obj.a
+
+    obj.a = 2
+
+    assert.equal obj.a, 2
+    assert.equal obj().a, obj.a
+
+  it "should work with observable properties", ->
+    obj = Observable
+      a: Observable 1
+
+    assert.equal obj.a, 1
+    assert.equal obj().a(), obj.a
+
+    obj().a 2
+
+    assert.equal obj.a, 2
+    assert.equal obj().a(), obj.a
+
+    obj.a = 3
+
+    assert.equal obj.a, 3
+    assert.equal obj().a(), obj.a
+
+  it "should compute object#extend as a dependency", ->
+    obj = Observable
+      a: 1
+
+    obj.extend b: 2
+
+    assert.equal obj.b, 2
+    assert.equal obj().b, obj.b
+
+    # alias
+    obj.assign c: 3
+
+    assert.equal obj.c, 3
+    assert.equal obj().c, obj.c
+
+  it "should compute object#remove as a dependency", ->
+    obj = Observable
+      a: 1
+      b: 2
+
+    obj.remove "b"
+
+    assert.equal obj.b, undefined
+
+  it "should proxy object methods", ->
+    obj = Observable
+      a: 1
+      b: 2
+
+    assert.deepEqual obj.keys, ["a", "b"]
+    assert.deepEqual obj.values, [1, 2]
+    assert.deepEqual obj.entries, [["a", 1], ["b", 2]]