Reusable array search predicates

reusableArraySearchPredicates.js

// CREDIT TO: https://jasonformat.com/reusable-array-search-predicates/
// Given an Array of objects:
const blogPosts = [
  { name:'one', tags:['a', 'b'], published: '2016-10-31' },
  { name:'two', tags:['c'], published: '2019-01-05' },
  { name:'three', tags:['b'], published: '2021-06-06' },
  ...
];

// Create reusable search predicates using `this`:
function $hasName(item) { return item.name === this }
function $hasTag(item) { return item.tags.includes(this) }
function $publishedAfter(item) { return new Date(item.published) > this }

// ...and specify the comparison value dynamically:
blogPosts.find($hasName, 'one');      // {name:'one'…}
blogPosts.findIndex($hasName, 'two'); // 1

blogPosts.every($hasTag, 'b');        // true
blogPosts.filter($hasTag, 'b');       // [{name:'one'…}, {name:'three'…}]
blogPosts.filter($publishedAfter, new Date(2020, 12, 25));  // [{name:'three'…}]