It’s part of the ES6 module system, described here. There is a helpful example in that documentation, also: If a module defines a default export: // foo.js export default function() { console.log(“hello!”) } then you can import that default export by omitting the curly braces: import foo from “foo”; foo(); // hello! Update: As of … Read more
This is a default import: // B.js import A from ‘./A’ It only works if A has the default export: // A.js export default 42 In this case it doesn’t matter what name you assign to it when importing: // B.js import A from ‘./A’ import MyA from ‘./A’ import Something from ‘./A’ Because it … Read more
Update Since Node v12 (April 2019), support for ES modules is enabled by default, and since Node v15 (October 2020) it’s stable (see here). Files including node modules must either end in .mjs or the nearest package.json file must contain “type”: “module”. The Node documentation has a ton more information, also about interop between CommonJS … Read more
If you take advantage of how == works, you could simply create an object with a custom toString (or valueOf) function that changes what it returns each time it is used such that it satisfies all three conditions. const a = { i: 1, toString: function () { return a.i++; } } if(a == 1 … Read more