35 lines
881 B
Markdown
35 lines
881 B
Markdown
### checkProp
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Given a `predicate` function and a `prop` string, this curried function will then take an `object` to inspect by calling the property and passing it to the predicate.
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Summon `prop` on `obj`, pass it to a provided `predicate` function and return a masked boolean.
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```js
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const checkProp = (predicate, prop) => obj => !!predicate(obj[prop]);
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```
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```js
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const lengthIs4 = checkProp(l => l === 4, 'length');
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lengthIs4([]); // false
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lengthIs4([1,2,3,4]); // true
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lengthIs4(new Set([1,2,3,4])); // false (Set uses Size, not length)
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const session = { user: {} };
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const validUserSession = checkProps(u => u.active && !u.disabled, 'user');
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validUserSession(session); // false
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session.user.active = true;
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validUserSession(session); // true
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const noLength(l => l === undefined, 'length');
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noLength([]); // false
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noLength({}); // true
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noLength(new Set()); // true
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```
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