fix(angular): remove form control side effects

[liamdebeasi]

Issue number: resolves #28358

---

What is the current behavior?

28f2ec9 exposed a (possible) ng-packagr bug where the form control components were being re-assigned, which breaks treeshaking. These components were considered side effects and were always being pulled into the bundle.

This resulted in a higher than expected bundle size. This issue appears to be caused by using 2 decorators and referring to the class in useExisting (for providers). Doing just one of these does not reproduce the issue.

The compiled output looks something like this:

let IonToggle = IonToggle_1 = /*@__PURE__*/ class IonToggle extends ValueAccessor {
    constructor(c, r, z, injector) {
        super(injector, r);
        this.z = z;
        c.detach();
        this.el = r.nativeElement;
        proxyOutputs(this, this.el, ['ionChange', 'ionFocus', 'ionBlur']);
    }
    writeValue(value) {
        this.elementRef.nativeElement.checked = this.lastValue = value;
        setIonicClasses(this.elementRef);
    }
    handleIonChange(el) {
        this.handleValueChange(el, el.checked);
    }
};
/** @nocollapse */ IonToggle.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "14.2.12", ngImport: i0, type: IonToggle, deps: [{ token: i0.ChangeDetectorRef }, { token: i0.ElementRef }, { token: i0.NgZone }, { token: i0.Injector }], target: i0.ɵɵFactoryTarget.Component });
/** @nocollapse */ IonToggle.ɵcmp = i0.ɵɵngDeclareComponent({ minVersion: "14.0.0", version: "14.2.12", type: IonToggle, isStandalone: true, selector: "ion-toggle", inputs: { checked: "checked", color: "color", disabled: "disabled", enableOnOffLabels: "enableOnOffLabels", justify: "justify", labelPlacement: "labelPlacement", legacy: "legacy", mode: "mode", name: "name", value: "value" }, host: { listeners: { "ionChange": "handleIonChange($event.target)" } }, providers: [
        {
            provide: NG_VALUE_ACCESSOR,
            useExisting: IonToggle_1,
            multi: true,
        },
    ], usesInheritance: true, ngImport: i0, template: '<ng-content></ng-content>', isInline: true, changeDetection: i0.ChangeDetectionStrategy.OnPush });
IonToggle = IonToggle_1 = __decorate([
    ProxyCmp({
        defineCustomElementFn: defineCustomElement$1i,
        inputs: TOGGLE_INPUTS,
    })
], IonToggle);

What is the new behavior?

• Removed the ProxyCmp usage in favor of manually calling proxyInputs and proxyMethods.
• Also saw that select was missing a form control test, so I added one

The compiled code now looks something like this:

class IonToggle extends ValueAccessor {
    constructor(c, r, z, injector) {
        super(injector, r);
        this.z = z;
        defineCustomElement$1i();
        proxyInputs(IonToggle, TOGGLE_INPUTS);
        c.detach();
        this.el = r.nativeElement;
        proxyOutputs(this, this.el, ['ionChange', 'ionFocus', 'ionBlur']);
    }
    writeValue(value) {
        this.elementRef.nativeElement.checked = this.lastValue = value;
        setIonicClasses(this.elementRef);
    }
    handleIonChange(el) {
        this.handleValueChange(el, el.checked);
    }
}
/** @nocollapse */ IonToggle.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "14.2.12", ngImport: i0, type: IonToggle, deps: [{ token: i0.ChangeDetectorRef }, { token: i0.ElementRef }, { token: i0.NgZone }, { token: i0.Injector }], target: i0.ɵɵFactoryTarget.Component });
/** @nocollapse */ IonToggle.ɵcmp = i0.ɵɵngDeclareComponent({ minVersion: "14.0.0", version: "14.2.12", type: IonToggle, isStandalone: true, selector: "ion-toggle", inputs: { checked: "checked", color: "color", disabled: "disabled", enableOnOffLabels: "enableOnOffLabels", justify: "justify", labelPlacement: "labelPlacement", legacy: "legacy", mode: "mode", name: "name", value: "value" }, host: { listeners: { "ionChange": "handleIonChange($event.target)" } }, providers: [
        {
            provide: NG_VALUE_ACCESSOR,
            useExisting: IonToggle,
            multi: true,
        },
    ], usesInheritance: true, ngImport: i0, template: '<ng-content></ng-content>', isInline: true, changeDetection: i0.ChangeDetectionStrategy.OnPush });

Does this introduce a breaking change?

• Yes
• No

Other information

Ryan provided some context on a related Stencil bug where doing reassignments broke treeshaking in Webpack. While the source of this bug is not Stencil, understanding the Stencil bug helped me better understand this issue:

stenciljs/core#3191
stenciljs/core#3248
stenciljs/core#4188 (fixes an issue introduced in the above stencil PR)

Dev build: 7.5.1-dev.11697480817.10fa2601

[thetaPC]

LGTM