init

dist/deep-copy.js

@@ -0,0 +1,47 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+/** from  https://github.com/vuejs/vuex/blob/dev/src/util.js
+ * Get the first item that pass the test
+ * by second argument function
+ *
+ * @param {Array} list
+ * @param {Function} f
+ * @return {*}
+ */
+function find(list, f) {
+    return list.filter(f)[0];
+}
+/**
+ * Deep copy the given object considering circular structure.
+ * This function caches all nested objects and its copies.
+ * If it detects circular structure, use cached copy to avoid infinite loop.
+ *
+ * @param {*} obj
+ * @param {Array<Object>} cache
+ * @return {*}
+ */
+function deepCopy(obj, cache) {
+    if (cache === void 0) { cache = []; }
+    // just return if obj is immutable value
+    if (obj === null || typeof obj !== 'object') {
+        return obj;
+    }
+    // if obj is hit, it is in circular structure
+    var hit = find(cache, function (c) { return c.original === obj; });
+    if (hit) {
+        return hit.copy;
+    }
+    var copy = Array.isArray(obj) ? [] : {};
+    // put the copy into cache at first
+    // because we want to refer it in recursive deepCopy
+    cache.push({
+        original: obj,
+        copy: copy
+    });
+    Object.keys(obj).forEach(function (key) {
+        copy[key] = deepCopy(obj[key], cache);
+    });
+    return copy;
+}
+exports.deepCopy = deepCopy;
+//# sourceMappingURL=deep-copy.js.map

dist/deep-copy.js.map

@@ -0,0 +1 @@
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package.json

@@ -0,0 +1,11 @@
+{
+  "name": "fast-deep-copy",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC"
+}

readme.md

@@ -0,0 +1,3 @@
+```js
+    import { deepCopy } from 'fast-deep-copy'
+```

src/deep-copy.ts

@@ -0,0 +1,47 @@
+/** from  https://github.com/vuejs/vuex/blob/dev/src/util.js
+ * Get the first item that pass the test
+ * by second argument function
+ *
+ * @param {Array} list
+ * @param {Function} f
+ * @return {*}
+ */
+function find(list, f) {
+    return list.filter(f)[0]
+}
+
+/**
+ * Deep copy the given object considering circular structure.
+ * This function caches all nested objects and its copies.
+ * If it detects circular structure, use cached copy to avoid infinite loop.
+ *
+ * @param {*} obj
+ * @param {Array<Object>} cache
+ * @return {*}
+ */
+export function deepCopy<T>(obj: T, cache = []): T {
+    // just return if obj is immutable value
+    if (obj === null || typeof obj !== 'object') {
+        return obj
+    }
+
+    // if obj is hit, it is in circular structure
+    const hit = find(cache, c => c.original === obj)
+    if (hit) {
+        return hit.copy
+    }
+
+    const copy = Array.isArray(obj) ? [] : {}
+    // put the copy into cache at first
+    // because we want to refer it in recursive deepCopy
+    cache.push({
+        original: obj,
+        copy
+    })
+
+    Object.keys(obj).forEach(key => {
+        copy[key] = deepCopy(obj[key], cache)
+    })
+
+    return <T>copy;
+}

tsconfig.json

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+ {
+     "compileOnSave": true,
+     "compilerOptions": {
+         "module": "commonjs",
+         "target": "es5",
+         "sourceMap": true,
+         "allowJs":true,
+         "moduleResolution": "node",
+         "outDir": "dist"         
+     },
+     "include": [
+         "src/**/*"
+     ]
+ }