39 lines
750 B
Markdown
39 lines
750 B
Markdown
### deepFreeze
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Deep freezes an object.
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Calls `Object.freeze(obj)` recursively on all unfrozen properties of obj that are `typeof` function or object.
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```js
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const deepFreeze = obj => {
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Object.freeze(obj);
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Object.getOwnPropertyNames(obj).forEach(function(prop) {
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if (
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obj.hasOwnProperty(prop) &&
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obj[prop] !== null &&
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(typeof obj[prop] === 'object' || typeof obj[prop] === 'function') &&
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!Object.isFrozen(obj[prop])
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) {
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deepFreeze(obj[prop]);
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}
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});
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return obj;
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};
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```
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```js
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'use strict';
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const a = Object.freeze([1, [2, 3]]);
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a[0] = 3; // not allowed
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a[1][0] = 4; // allowed but shouldn't be
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const b = deepFreeze([1, [2, 3]]);
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b[0] = 3; // not allowed
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b[1][0] = 4; // not allowed as well
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```
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