Closed
Description
Problem Statement
When using field initializers with typescript, our bundling process does something like so:
constructor() {
At.prototype.__init.call(this), At.prototype.__init2.call(this), At.prototype.__init3.call(this), At.prototype.__init4.call(this), At.prototype.__init5.call(this), At.prototype.__init6.call(this), At.prototype.__init7.call(this), At.prototype.__init8.call(this), At.prototype.__init9.call(this), At.prototype.__init10.call(this)
}
__init() {
this.m = !1
}
__init2() {
this.g = []
}
__init3() {
this._ = []
}
__init4() {
this.S = []
}
__init5() {
this.k = {}
}
__init6() {
this.O = {}
}
__init7() {
this.j = {}
}
__init8() {
this.T = {}
}
__init9() {
this.D = []
}
__init10() {
this.R = {}
}Each __initX() call is generated from a field initializer of a class. This is a bunch of extra bytes. See an example here: https://sucrase.io/#selectedTransforms=typescript,imports&code=class%20Scope%20%7B%0A%20%20public%20a%20%3D%203%3B%0A%7D.
This is done to best match TS behaviour. See https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#the-usedefineforclassfields-flag-and-the-declare-property-modifier for more details.
Solution Brainstorm
Evidence: #5306
In the mean time, I think avoiding usage of field initializers in favour of initializing the field in a constructor is the best course of action to reduce bundle size.