Last active
January 19, 2020 19:07
-
-
Save antongolub/4accfec9f03774a5fb5ae30a5319259a to your computer and use it in GitHub Desktop.
Apply mixins as a sub-class
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| export const applyMixinsFixed = <T extends IConstructable, U extends IConstructable[]>(target: T, ...mixins: U) => { | |
| class Mixed extends target { | |
| constructor(...args: any[]) { | |
| super(...args) | |
| mergeDescriptors(this, ...mixins.map(M => new M(...args))) | |
| } | |
| } | |
| mergeProto(Mixed, target, ...mixins) | |
| mergeDescriptors(Mixed, target, ...mixins) | |
| return Mixed | |
| } | |
| export const mergeProto = (target: any, ...mixins: any[]) => mergeDescriptors(target.prototype, ...mixins.map(a => a.prototype)) | |
| export const mergeDescriptors = <T, U extends any[]>(target: T, ...mixins: U): T & UnionToIntersection<U[number]> => | |
| mixins.reduce((m, v) => { | |
| Object.getOwnPropertyNames(v).forEach(name => { | |
| // TODO exclude other fields | |
| if (typeof v === 'function' && (name === 'length' || name === 'name')) { | |
| return | |
| } | |
| if (name === 'prototype' || name === 'constructor') { | |
| return | |
| } | |
| Object.defineProperty( | |
| m, | |
| name, | |
| Object.getOwnPropertyDescriptor(v, name) as PropertyDescriptor, | |
| ) | |
| }) | |
| return m | |
| }, target) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment