wycats

October 25, 2022 to November 4, 2022

Generics around missingness

function Name<S extends string | undefined>(name: S): S {
  return name;
}

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Making unique-id a importable function

The Use Cases

import { uniqueId } from "@ember/???";

<template>
  {{#let (unique-id) as |id|}}

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Factories

A factory is a function that returns a new reactive object.

• Reactive Factories return reactive objects.
• Resource Factories also return reactive objects, but they also register cleanup functions that are called when the object is no longer needed.

You can use a class as a factory, but it's not required. When you use a class as a factory, its constructor must take zero required arguments.

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I'm assuming these are all talking about cases that didn't already have semis:

Top-Level TemplateDeclaration

<template>
  Hello
</template>|
//         ^ 🚫

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import { Cell } from "@starbeam/core";
import { useSetup } from "@starbeam/react";

const SYSTEM_LOCALE = Intl.DateTimeFormat().resolvedOptions().locale;
const SYSTEM_TZ = Intl.DateTimeFormat().resolvedOptions().timeZone;

function Clock({ locale = SYSTEM_LOCALE, timeZone = SYSTEM_TZ }) {
  const now = useSetup((component) => { 
    const now = Cell(new Date()));

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import Component from '@glimmer/component';

export default class extends Component {
}

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// observed popover is interested in changes to `width` and `height` relative to the
// page's origin, and normalized by rounding them to the nearest integer.
let observedPopover = new RectObserver(
  popoverElement,
  {
    width: Math.round,
    height: Math.round
  },
  {
    relativeTo: 'origin' // not viewport

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import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  value: 'Hello world',
  
  inputted(e) {
    Ember.set(this, 'value', e.target.value);
  }
});

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// default tagName is 'div'

// The problem

function createElement(tagName: string): Element {
  // very broken
  return document.createElement(tagName || 'div');
}

// you might want to use defaults

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import Ember from 'ember';

export default Ember.Component.extend({
});