bug: broken codegen for collections of named types in EventEmitter

[aniederer-chatham]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Stencil Version

4.8.1

Stencil Framework Output Target

Angular

Stencil Framework Output Target Version

0.8.3

Current Behavior

The emitted type for AppRoot is

export declare interface AppRoot extends Components.AppRoot {
  e: EventEmitter<CustomEvent<IAppRoot{ a: [object Object]; }>>;
}

which is invalid TypeScript

Expected Behavior

The emitted type for AppRoot is

export declare interface AppRoot extends Components.AppRoot {
  e: EventEmitter<CustomEvent<{ a: IAppRootA; }>>;
}

Steps to Reproduce

• Pull the repro repo and run npm run build in the repo root
• Open the generated file at /angular-output-target/projects/stencil-components/src/lib/components.ts
• Go to line 33 or search for "export declare interface AppRoot"
• Notice the invalid syntax emitted for the type of AppRoot#e

The component which causes the broken codegen is defined as follows:

import { Component, Host, Event, EventEmitter, h } from '@stencil/core';

export type A = { };

@Component({ tag: 'app-root', shadow: true, })
export class AppRoot {
  @Event() readonly e!: EventEmitter<{ a: A; }>;
  render() {
    return <Host></Host>
  }
}

Another alternative definition which also exhibits the pathological behavior is as follows:

import { Component, Host, Event, EventEmitter, h } from '@stencil/core';

export type A = { };

@Component({ tag: 'app-root', shadow: true, })
export class AppRoot {
  @Event() readonly e!: EventEmitter<readonly A[]>;
  render() {
    return <Host></Host>
  }
}

Code Reproduction URL

https://github.com/aniederer-chatham/stencil-angular-type-bug-poc

Additional Information

This also occurs when the object is readonly, emitting <IAppRootreadonly {a: [object Object]; }>

This happens effectively every time you write a type that a basic search-and-replace would mess up, for example EventEmitter<readonly A[]> outputs EventEmitter<CustomEvent<IAppRootreadonly [object Object][]>>. I'm guessing the codegen there isn't very robust.

[ionitron-bot]

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