From eb008c31fbd5dcd1e56362d026d63c5f89f6d4a7 Mon Sep 17 00:00:00 2001
From: ElliotNB <elliot.bradshaw@transformativemed.com>
Date: Tue, 21 Aug 2018 20:49:38 -0700
Subject: [PATCH] Bug fix for issue where multiple observers on same object can
 trigger before mutation has been applied.

---
 observable-slim.js     | 18 ++++++++----------
 observable-slim.min.js |  2 +-
 test/test.js           | 16 +++++++++++++++-
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/observable-slim.js b/observable-slim.js
index fff06b0..7dae880 100644
--- a/observable-slim.js
+++ b/observable-slim.js
@@ -219,6 +219,9 @@ var ObservableSlim = (function() {
 
 				if (originalChange === true) {
 
+					// perform the delete that we've trapped if changes are not paused for this observable
+					if (!observable.changesPaused) delete target[property];
+				
 					for (var a = 0, l = targets.length; a < l; a++) if (target === targets[a]) break;
 
 					// loop over each proxy and see if the target for this change has any other proxies
@@ -238,10 +241,6 @@ var ObservableSlim = (function() {
 						}
 					}
 
-					// perform the delete that we've trapped if changes are not paused for this observable
-					if (!observable.changesPaused)
-						delete target[property];
-
 				}
 
 				_notifyObservers(changes.length);
@@ -307,6 +306,11 @@ var ObservableSlim = (function() {
 					// observers can be modified of the change that has occurred.
 					if (originalChange === true) {
 
+						// because the value actually differs than the previous value
+						// we need to store the new value on the original target object,
+						// but only as long as changes have not been paused
+						if (!observable.changesPaused) target[property] = value;
+					
 						for (var a = 0, l = targets.length; a < l; a++) if (target === targets[a]) break;
 
 						foundObservable = (a < l);
@@ -397,12 +401,6 @@ var ObservableSlim = (function() {
 							},10000);
 						}
 
-						// because the value actually differs than the previous value
-						// we need to store the new value on the original target object,
-						// but only as long as changes have not been paused
-						if (!observable.changesPaused)
-							target[property] = value;
-
 						// TO DO: the next block of code resolves test case #24, but it results in poor IE11 performance. Find a solution.
 						//
 						// if the value we've just set is an object, then we'll need to iterate over it in order to initialize the
diff --git a/observable-slim.min.js b/observable-slim.min.js
index 6b3a535..b7baaed 100644
--- a/observable-slim.min.js
+++ b/observable-slim.min.js
@@ -1 +1 @@
-var ObservableSlim=function(){paths=[];var l=[],d=[],_=[],x=null,f=function(e,i,r,t){var h=r||null,u=t||[{target:e,property:""}];paths.push(u),e instanceof Array&&(e.__length=e.length);var c=[],v=function(e,r,t){for(var n="",a=null,o=0;o<u.length;o++)a instanceof Array&&!isNaN(u[o].property)&&(u[o].property=a.indexOf(u[o].target)),n=n+"."+u[o].property,a=u[o].target;return n=(n=n+"."+r).substring(2),!0===t&&(n="/"+n.replace(/\./g,"/")),n},b=function(t){if(!0!==h.paused)if(!0===i)setTimeout(function(){if(t===c.length){var e=c.slice(0);c=[];for(var r=0;r<h.observers.length;r++)h.observers[r](e)}},10);else{var e=c.slice(0);c=[];for(var r=0;r<h.observers.length;r++)h.observers[r](e)}},y=new Proxy(e,{get:function(e,r){if("__getTarget"===r)return e;if("__isProxy"===r)return!0;if("__getParent"===r)return function(e){if(void 0===e)e=1;var r,t=v(0,"__getParent").split(".");return t.splice(-(e+1),e+1),r=h.parentProxy,t.join(".").split(".").reduce(function(e,r){return e?e[r]:void 0},r||self)};var t=e[r];if(t instanceof Object&&null!==t&&e.hasOwnProperty(r)){!0===t.__isProxy&&(t=t.__getTarget);for(var n=-1,a=h.targets,o=0,s=a.length;o<s;o++)if(t===a[o]){n=o;break}if(-1<n)return h.proxies[n];var l=u.slice(0);return l.push({target:t,property:r}),f(t,i,h,l)}return t},deleteProperty:function(e,r){var t=!0;x===y&&(t=!1,x=null);var n=Object.assign({},e);if(c.push({type:"delete",target:e,property:r,newValue:null,previousValue:n[r],currentPath:v(0,r),jsonPointer:v(0,r,!0),proxy:y}),!0===t){for(var a=0,o=d.length;a<o&&e!==d[a];a++);for(var s=_[a],l=s.length;l--;)s[l].proxy!==y&&(x=s[l].proxy,delete s[l].proxy[r]);h.changesPaused||delete e[r]}return b(c.length),!0},set:function(n,e,r,t){r.__isProxy&&(r=r.__getTarget);var a=!0;x===y&&(a=!1,x=null);var o=n[e];if(o!==r||!1===a||"length"===e&&n instanceof Array&&n.__length!==r){var s=!0,l=typeof o,i="update";if("undefined"===l&&(i="add"),c.push({type:i,target:n,property:e,newValue:r,previousValue:t[e],currentPath:v(0,e),jsonPointer:v(0,e,!0),proxy:y}),"length"===e&&n instanceof Array&&n.__length!==r&&(c[c.length-1].previousValue=n.__length,n.__length=r),!0===a){for(var u=0,f=d.length;u<f&&n!==d[u];u++);if(s=u<f){var p=_[u],g=0;for(f=p.length;g<f;g++)p[g].proxy!==y&&(x=p[g].proxy,p[g].proxy[e]=r);setTimeout(function(){if("object"===l&&null!==o){for(var e=Object.keys(n),r=0,t=e.length;r<t;r++)if(n[e[r]]===o)return;!function e(r){for(var t=Object.keys(r),n=0,a=t.length;n<a;n++){var o=r[t[n]];o instanceof Object&&null!==o&&e(o)}var s=-1;for(n=0,a=d.length;n<a;n++)if(r===d[n]){s=n;break}if(-1<s){for(var l=_[s],i=l.length;i--;)if(h===l[i].observable){l.splice(i,1);break}0==l.length&&(_.splice(s,1),d.splice(s,1))}}(o)}},1e4)}h.changesPaused||(n[e]=r)}s&&b(c.length)}return!0}});null===h?(h={parentTarget:e,domDelay:i,parentProxy:y,observers:[],targets:[e],proxies:[y],paused:!1,path:u,changesPaused:!1},l.push(h)):(h.targets.push(e),h.proxies.push(y));for(var n={target:e,proxy:y,observable:h},a=-1,o=0,s=d.length;o<s;o++)if(e===d[o]){a=o;break}return-1<a?_[a].push(n):(d.push(e),_.push([n]),a=d.length-1),y};return{create:function(e,r,t){if(!0===e.__isProxy)e=e.__getTarget;var n=f(e,r);return"function"==typeof t&&this.observe(n,t),function e(r){for(var t=r.__getTarget,n=Object.keys(t),a=0,o=n.length;a<o;a++){var s=n[a];t[s]instanceof Object&&null!==t[s]&&e(r[s])}}(n),n},observe:function(e,r){for(var t=l.length;t--;)if(l[t].parentProxy===e){l[t].observers.push(r);break}},pause:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=l[r].paused=!0;break}if(0==t)throw new Error("ObseravableSlim could not pause observable -- matching proxy not found.")},resume:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=!(l[r].paused=!1);break}if(0==t)throw new Error("ObseravableSlim could not resume observable -- matching proxy not found.")},pauseChanges:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=l[r].changesPaused=!0;break}if(0==t)throw new Error("ObseravableSlim could not pause changes on observable -- matching proxy not found.")},resumeChanges:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=!(l[r].changesPaused=!1);break}if(0==t)throw new Error("ObseravableSlim could not resume changes on observable -- matching proxy not found.")},remove:function(e){for(var r=null,t=!1,n=l.length;n--;)if(l[n].parentProxy===e){r=l[n],t=!0;break}for(var a=_.length;a--;)for(var o=_[a].length;o--;)_[a][o].observable===r&&(_[a].splice(o,1),0===_[a].length&&(_.splice(a,1),d.splice(a,1)));!0===t&&l.splice(n,1)}}}();try{module.exports=ObservableSlim}catch(e){}
\ No newline at end of file
+var ObservableSlim=function(){paths=[];var l=[],d=[],_=[],x=null,f=function(e,i,r,t){var h=r||null,u=t||[{target:e,property:""}];paths.push(u),e instanceof Array&&(e.__length=e.length);var c=[],v=function(e,r,t){for(var n="",a=null,o=0;o<u.length;o++)a instanceof Array&&!isNaN(u[o].property)&&(u[o].property=a.indexOf(u[o].target)),n=n+"."+u[o].property,a=u[o].target;return n=(n=n+"."+r).substring(2),!0===t&&(n="/"+n.replace(/\./g,"/")),n},b=function(t){if(!0!==h.paused)if(!0===i)setTimeout(function(){if(t===c.length){var e=c.slice(0);c=[];for(var r=0;r<h.observers.length;r++)h.observers[r](e)}},10);else{var e=c.slice(0);c=[];for(var r=0;r<h.observers.length;r++)h.observers[r](e)}},y=new Proxy(e,{get:function(e,r){if("__getTarget"===r)return e;if("__isProxy"===r)return!0;if("__getParent"===r)return function(e){if(void 0===e)e=1;var r,t=v(0,"__getParent").split(".");return t.splice(-(e+1),e+1),r=h.parentProxy,t.join(".").split(".").reduce(function(e,r){return e?e[r]:void 0},r||self)};var t=e[r];if(t instanceof Object&&null!==t&&e.hasOwnProperty(r)){!0===t.__isProxy&&(t=t.__getTarget);for(var n=-1,a=h.targets,o=0,s=a.length;o<s;o++)if(t===a[o]){n=o;break}if(-1<n)return h.proxies[n];var l=u.slice(0);return l.push({target:t,property:r}),f(t,i,h,l)}return t},deleteProperty:function(e,r){var t=!0;x===y&&(t=!1,x=null);var n=Object.assign({},e);if(c.push({type:"delete",target:e,property:r,newValue:null,previousValue:n[r],currentPath:v(0,r),jsonPointer:v(0,r,!0),proxy:y}),!0===t){h.changesPaused||delete e[r];for(var a=0,o=d.length;a<o&&e!==d[a];a++);for(var s=_[a],l=s.length;l--;)s[l].proxy!==y&&(x=s[l].proxy,delete s[l].proxy[r])}return b(c.length),!0},set:function(n,e,r,t){r&&r.__isProxy&&(r=r.__getTarget);var a=!0;x===y&&(a=!1,x=null);var o=n[e];if(o!==r||!1===a||"length"===e&&n instanceof Array&&n.__length!==r){var s=!0,l=typeof o,i="update";if("undefined"===l&&(i="add"),c.push({type:i,target:n,property:e,newValue:r,previousValue:t[e],currentPath:v(0,e),jsonPointer:v(0,e,!0),proxy:y}),"length"===e&&n instanceof Array&&n.__length!==r&&(c[c.length-1].previousValue=n.__length,n.__length=r),!0===a){h.changesPaused||(n[e]=r);for(var u=0,f=d.length;u<f&&n!==d[u];u++);if(s=u<f){var p=_[u],g=0;for(f=p.length;g<f;g++)p[g].proxy!==y&&(x=p[g].proxy,p[g].proxy[e]=r);setTimeout(function(){if("object"===l&&null!==o){for(var e=Object.keys(n),r=0,t=e.length;r<t;r++)if(n[e[r]]===o)return;!function e(r){for(var t=Object.keys(r),n=0,a=t.length;n<a;n++){var o=r[t[n]];o instanceof Object&&null!==o&&e(o)}var s=-1;for(n=0,a=d.length;n<a;n++)if(r===d[n]){s=n;break}if(-1<s){for(var l=_[s],i=l.length;i--;)if(h===l[i].observable){l.splice(i,1);break}0==l.length&&(_.splice(s,1),d.splice(s,1))}}(o)}},1e4)}}s&&b(c.length)}return!0}});null===h?(h={parentTarget:e,domDelay:i,parentProxy:y,observers:[],targets:[e],proxies:[y],paused:!1,path:u,changesPaused:!1},l.push(h)):(h.targets.push(e),h.proxies.push(y));for(var n={target:e,proxy:y,observable:h},a=-1,o=0,s=d.length;o<s;o++)if(e===d[o]){a=o;break}return-1<a?_[a].push(n):(d.push(e),_.push([n]),a=d.length-1),y};return{create:function(e,r,t){if(!0===e.__isProxy)e=e.__getTarget;var n=f(e,r);return"function"==typeof t&&this.observe(n,t),function e(r){for(var t=r.__getTarget,n=Object.keys(t),a=0,o=n.length;a<o;a++){var s=n[a];t[s]instanceof Object&&null!==t[s]&&e(r[s])}}(n),n},observe:function(e,r){for(var t=l.length;t--;)if(l[t].parentProxy===e){l[t].observers.push(r);break}},pause:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=l[r].paused=!0;break}if(0==t)throw new Error("ObseravableSlim could not pause observable -- matching proxy not found.")},resume:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=!(l[r].paused=!1);break}if(0==t)throw new Error("ObseravableSlim could not resume observable -- matching proxy not found.")},pauseChanges:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=l[r].changesPaused=!0;break}if(0==t)throw new Error("ObseravableSlim could not pause changes on observable -- matching proxy not found.")},resumeChanges:function(e){for(var r=l.length,t=!1;r--;)if(l[r].parentProxy===e){t=!(l[r].changesPaused=!1);break}if(0==t)throw new Error("ObseravableSlim could not resume changes on observable -- matching proxy not found.")},remove:function(e){for(var r=null,t=!1,n=l.length;n--;)if(l[n].parentProxy===e){r=l[n],t=!0;break}for(var a=_.length;a--;)for(var o=_[a].length;o--;)_[a][o].observable===r&&(_[a].splice(o,1),0===_[a].length&&(_.splice(a,1),d.splice(a,1)));!0===t&&l.splice(n,1)}}}();try{module.exports=ObservableSlim}catch(e){}
\ No newline at end of file
diff --git a/test/test.js b/test/test.js
index 7849f20..febdc33 100644
--- a/test/test.js
+++ b/test/test.js
@@ -620,10 +620,24 @@ function suite(proxy) {
 
 	});
 	
+	it('30. Verify that a mutation on an object observed by two handlers returns the correct new value in both handlers.', () => {
+		
+		var data = {"foo":"bar"};
+		var p = ObservableSlim.create(data, false, function(changes) { 
+			expect(p.foo).to.equal("test");
+		});
+		
+		var pp = ObservableSlim.create(p, false, function(changes) { 
+			expect(p.foo).to.equal("test");
+		});
+		
+		p.foo = "test";		
+	});
+	
 	
 	// This test currently does not have an expectation or assertion. For now it simply
 	// ensures that the garbage clean-up code runs and that the garbage clean-up doesn't throw an error.
- 	it('30. Clean-up observers of overwritten (orphaned) objects.', (done) => {
+ 	it('31. Clean-up observers of overwritten (orphaned) objects.', (done) => {
 
 		var data = {"testing":{"test":{"testb":"hello world"},"testc":"hello again"},"blah":{"tree":"world"}};
 		var p = ObservableSlim.create(data, false, function(changes) {