defaultMember already is an alias – it doesn’t need to be the name of the exported function/thing. Just do import alias from ‘my-module’; Alternatively you can do import {default as alias} from ‘my-module’; but that’s rather esoteric.
tl;dr: No! Arrow functions and function declarations / expressions are not equivalent and cannot be replaced blindly. If the function you want to replace does not use this, arguments and is not called with new, then yes. As so often: it depends. Arrow functions have different behavior than function declarations / expressions, so let’s have … Read more
You can await on Promise.all(): await Promise.all([someCall(), anotherCall()]); To store the results: let [someResult, anotherResult] = await Promise.all([someCall(), anotherCall()]); Note that Promise.all fails fast, which means that as soon as one of the promises supplied to it rejects, then the entire thing rejects. const happy = (v, ms) => new Promise((resolve) => setTimeout(() => resolve(v), … Read more
I got this error because I forgot the type=”module” inside the script tag: <script type=”module” src=”milsymbol-2.0.0/src/milsymbol.js”></script>
You must wrap the returning object literal into parentheses. Otherwise curly braces will be considered to denote the function’s body. The following works: p => ({ foo: ‘bar’ }); You don’t need to wrap any other expression into parentheses: p => 10; p => ‘foo’; p => true; p => [1,2,3]; p => null; p … Read more
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
Scoping rules The main difference is scoping rules. Variables declared by var keyword are scoped to the immediate function body (hence the function scope) while let variables are scoped to the immediate enclosing block denoted by { } (hence the block scope). function run() { var foo = “Foo”; let bar = “Bar”; console.log(foo, bar); … Read more