chore: improve component method typings

src/commands/context/types.ts

@@ -8,7 +8,6 @@ import type { closeOtherPages } from "./command/close-other-pages";
 import type { lastPage } from "./command/last-page";
 import type { newPage } from "./command/new-page";
 
-// @ts-ignore
 export interface BrowserContext extends PlaywrightBrowserContextType, BrowserContextClassType {
   config: Config;
   attach: IWorldOptions["attach"];

src/commands/locator/types.ts

@@ -32,9 +32,7 @@ import type { scrollIntoView } from "./command/scroll-into-view";
 import type { selectOption } from "./command/select-option";
 import type { uploadFiles } from "./command/upload-files";
 
-// @ts-ignore
 export interface Locator extends PlaywrightLocatorType, LocatorClassType {
-  _selector: string;
   all: typeof all;
   and: typeof and;
   centerPoint: typeof centerPoint;

src/commands/page/command/component.ts

@@ -2,19 +2,35 @@ import { Locator as LocatorClass } from "@commands/locator/locator";
 
 import type { Page } from "@commands/page/types";
 import type { Locator } from "@commands/locator/types";
+import type { ExcludePropertiesOf } from "@common/types";
 import type { Component } from "@core/component";
 
-function getInstance(component: Component) {
-  const instance = new LocatorClass(component.root);
-  const componentProto = Object.getPrototypeOf(component);
-  Object.keys(component).forEach(key => instance[key] = component[key]);
-  Object.getOwnPropertyNames(componentProto).filter(i => i !== "constructor").forEach(prop => instance[prop] = componentProto[prop]);
-  Object.defineProperty(instance, "root", Object.getOwnPropertyDescriptor(Object.getPrototypeOf(componentProto), "root"));
+type ComponentInstance<T> = Locator & Component & T;
+
+type ComponentSubClass<T> = new(page: Page, parent: Locator) => T;
+
+function getInstance(subComponent: Component) {
+  const excluded = ["constructor"];
+  const instance = new LocatorClass(subComponent.root);
+  const subComponentProto = Object.getPrototypeOf(subComponent);
+  const componentProto = Object.getPrototypeOf(subComponentProto);
+  // intentional mutation going on here
+  // assign properties
+  Object.getOwnPropertyNames(subComponent)
+    .forEach(key => instance[key] = subComponent[key]);
+  // assign methods
+  Object.getOwnPropertyNames(subComponentProto)
+    .filter(i => !excluded.includes(i))
+    .forEach(prop => instance[prop] = subComponentProto[prop]);
+  // assign accessors
+  Object.getOwnPropertyNames(Object.getOwnPropertyDescriptors(componentProto))
+    .filter(i => !excluded.includes(i))
+    .forEach(prop =>Object.defineProperty(instance, prop, Object.getOwnPropertyDescriptor(componentProto, prop)));
   return instance;
 }
 
-export function component<T extends Component>(this: Page, Component: new(page: Page, parent: Locator) => T, parent?: Locator) {
-  const component = new Component(this, parent);
-  const instance = getInstance(component);
-  return instance as Locator & Component & T;
+export function component<T extends Component, U extends ExcludePropertiesOf<U, Locator>>(this: Page, SubComponent: ComponentSubClass<T>, parent?: U) {
+  const subComponent = new SubComponent(this, parent);
+  const instance = getInstance(subComponent);
+  return instance as ComponentInstance<T>;
 }

src/commands/page/types.ts

@@ -22,7 +22,6 @@ import type { scrollToBottom } from "./command/scroll-to-bottom";
 import type { scrollToTop } from "./command/scroll-to-top";
 import type { switchToFrame } from "./command/switch-to-frame";
 
-// @ts-ignore
 export interface Page extends PlaywrightPageType, PageClassType {
   context: () => BrowserContext;
   activeframe: FrameLocator;

src/common/types.ts

@@ -10,3 +10,6 @@ export type RecursivePartial<T> = {
 export type KeyValuePair = { key: string; value: string };
 
 export type MergeTuple<A extends any[], B extends any[]> = [...A, ...B];
+
+/** @see[Exactify](https://github.com/microsoft/TypeScript/issues/12936#issuecomment-368244671) */
+export type ExcludePropertiesOf<X extends T, T> = T & { [K in keyof X]: K extends keyof T ? X[K] : never }