Mix-ins

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Mix-ins

Abstract subclasses or mix-ins are templates for classes. An ECMAScript class can only have a single superclass, so multiple inheritance from tooling classes, for example, is not possible. The functionality must be provided by the superclass.

eg:

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const calculatorMixin = (Base) =>
  class extends Base {
    calc() {
      // do something
    }
  }

const randomizerMixin = (Base) =>
  class extends Base {
    remdomize() {
      // do something
    }
  }

class Foo {}
class Bar extends calculatorMixin(randomizerMixin(Foo)) {}
const bar = new Bar()
console.log(bar.calc)
console.log(bar.remdomize) // also a function.