on-change - npm Package Compare versions

Comparing version 0.2.0 to 1.0.0

index.js

 'use strict';
 
-const blacklist = [
-	'sort',
-	'reverse',
-	'splice',
-	'pop',
-	'unshift',
-	'shift',
-	'push'
-];
+const isPrimitive = value => value === null || (typeof value !== 'object' && typeof value !== 'function');
 
+const proxyTarget = Symbol('ProxyTarget');
+
 module.exports = (object, onChange) => {
-	let isBlocked = false;
+	let inApply = false;
+	let changed = false;
+	const propCache = new WeakMap();
 
+	const handleChange = () => {
+		if (!inApply) {
+			onChange();
+		} else if (!changed) {
+			changed = true;
+		}
+	};
+
+	const getOwnPropertyDescriptor = (target, property) => {
+		if (!propCache.has(target)) {
+			propCache.set(target, new Map());
+		}
+
+		const props = propCache.get(target);
+		if (props.has(property)) {
+			return props.get(property);
+		}
+
+		const prop = Reflect.getOwnPropertyDescriptor(target, property);
+		props.set(property, prop);
+
+		return prop;
+	};
+
+	const invalidateCachedDescriptor = (target, property) => {
+		if (!propCache.has(target)) {
+			return;
+		}
+
+		const props = propCache.get(target);
+		props.delete(property);
+	};
+
 	const handler = {
 		get(target, property, receiver) {
-			try {
-				return new Proxy(target[property], handler);
-			} catch (_) {
-				return Reflect.get(target, property, receiver);
+			if (property === proxyTarget) {
+				return target;
 			}
+
+			const value = Reflect.get(target, property, receiver);
+			if (isPrimitive(value)) {
+				return value;
+			}
+
+			// Preserve invariants
+			const descriptor = getOwnPropertyDescriptor(target, property);
+			if (descriptor && !descriptor.configurable) {
+				if (descriptor.set && !descriptor.get) {
+					return undefined;
+				}
+
+				if (descriptor.writable === false) {
+					return value;
+				}
+			}
+
+			return new Proxy(value, handler);
 		},
+
+		set(target, property, value, receiver) {
+			if (value && value[proxyTarget] !== undefined) {
+				value = value[proxyTarget];
+			}
+
+			const previous = Reflect.get(target, property, value, receiver);
+			const result = Reflect.set(target, property, value);
+
+			if (previous !== value) {
+				handleChange();
+			}
+
+			return result;
+		},
+
 		defineProperty(target, property, descriptor) {
 			const result = Reflect.defineProperty(target, property, descriptor);
+			invalidateCachedDescriptor(target, property);
 
-			if (!isBlocked) {
-				onChange();
-			}
+			handleChange();
 
 			return result;
 		},
+
 		deleteProperty(target, property) {
 			const result = Reflect.deleteProperty(target, property);
+			invalidateCachedDescriptor(target, property);
 
-			if (!isBlocked) {
-				onChange();
-			}
+			handleChange();
 
 			return result;
 		},
+
 		apply(target, thisArg, argumentsList) {
-			if (blacklist.includes(target.name)) {
-				isBlocked = true;
+			if (!inApply) {
+				inApply = true;
+
 				const result = Reflect.apply(target, thisArg, argumentsList);
-				onChange();
-				isBlocked = false;
+
+				if (changed) {
+					onChange();
+				}
+
+				inApply = false;
+				changed = false;
+
 				return result;
@@ -49,0 +118,0 @@ }

package.json

 {
 	"name": "on-change",
-	"version": "0.2.0",
+	"version": "1.0.0",
 	"description": "Watch an object or array for changes",
@@ -39,3 +39,3 @@ "license": "MIT",
 	"devDependencies": {
-		"ava": "^0.25.0",
+		"ava": "^1.0.1",
 		"matcha": "^0.7.0",
@@ -42,0 +42,0 @@ "xo": "^0.23.0"

Fixed alerts

No v1

Quality

Package is not semver >=1. This means it is not stable and does not support ^ ranges.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

6355

increased by31.93%

Lines of code

93

increased by97.87%

Number of low quality alerts

1

decreased by-50%

No dependency changes