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refactor: dispose listeners on page destroyed #318

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merged 3 commits into from
Oct 13, 2025
Merged

refactor: dispose listeners on page destroyed #318

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fa79950
refactor: dispose listeners on page destroyed
Lightning00Blade Oct 8, 2025
aec0bce
fix
Lightning00Blade Oct 13, 2025
17e1f68
fix
Lightning00Blade Oct 13, 2025
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31 changes: 15 additions & 16 deletions src/McpContext.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@ import type {
PredefinedNetworkConditions,
} from 'puppeteer-core';

import type {ListenerMap} from './PageCollector.js';
import {NetworkCollector, PageCollector} from './PageCollector.js';
import {listPages} from './tools/pages.js';
import {takeSnapshot} from './tools/snapshot.js';
Expand Down Expand Up @@ -94,26 +95,24 @@ export class McpContext implements Context {
this.browser = browser;
this.logger = logger;

this.#networkCollector = new NetworkCollector(
this.browser,
(page, collect) => {
page.on('request', request => {
this.#networkCollector = new NetworkCollector(this.browser, collect => {
return {
request: request => {
collect(request);
});
},
);
},
} as ListenerMap;
});

this.#consoleCollector = new PageCollector(
this.browser,
(page, collect) => {
page.on('console', event => {
this.#consoleCollector = new PageCollector(this.browser, collect => {
return {
console: event => {
collect(event);
});
page.on('pageerror', event => {
},
pageerror: event => {
collect(event);
});
},
);
},
} as ListenerMap;
});
}

async #init() {
Expand Down
63 changes: 50 additions & 13 deletions src/PageCollector.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,25 @@
* SPDX-License-Identifier: Apache-2.0
*/

import type {Browser, HTTPRequest, Page} from 'puppeteer-core';
import {
type Browser,
type Frame,
type Handler,
type HTTPRequest,
type Page,
type PageEvents,
} from 'puppeteer-core';

export type ListenerMap<EventMap extends PageEvents = PageEvents> = {
[K in keyof EventMap]?: (event: EventMap[K]) => void;
};

export class PageCollector<T> {
#browser: Browser;
#initializer: (page: Page, collector: (item: T) => void) => void;
#listenersInitializer: (
collector: (item: T) => void,
) => ListenerMap<PageEvents>;
#listeners = new WeakMap<Page, ListenerMap>();
/**
* The Array in this map should only be set once
* As we use the reference to it.
Expand All @@ -18,10 +32,10 @@ export class PageCollector<T> {

constructor(
browser: Browser,
initializer: (page: Page, collector: (item: T) => void) => void,
listeners: (collector: (item: T) => void) => ListenerMap<PageEvents>,
) {
this.#browser = browser;
this.#initializer = initializer;
this.#listenersInitializer = listeners;
}

async init() {
Expand All @@ -37,6 +51,14 @@ export class PageCollector<T> {
}
this.#initializePage(page);
});
this.#browser.on('targetdestroyed', async target => {
const page = await target.page();
if (!page) {
return;
}
console.log('destro');
this.#cleanupPageDestroyed(page);
});
}

public addPage(page: Page) {
Expand All @@ -50,34 +72,49 @@ export class PageCollector<T> {

const stored: T[] = [];
this.storage.set(page, stored);

page.on('framenavigated', frame => {
const listeners = this.#listenersInitializer(value => {
stored.push(value);
});
listeners['framenavigated'] = (frame: Frame) => {
// Only reset the storage on main frame navigation
if (frame !== page.mainFrame()) {
return;
}
this.cleanup(page);
});
this.#initializer(page, value => {
stored.push(value);
});
this.cleanupAfterNavigation(page);
};

for (const [name, listener] of Object.entries(listeners)) {
page.on(name, listener as Handler<unknown>);
}

this.#listeners.set(page, listeners);
}

protected cleanup(page: Page) {
protected cleanupAfterNavigation(page: Page) {
const collection = this.storage.get(page);
if (collection) {
// Keep the reference alive
collection.length = 0;
}
}

#cleanupPageDestroyed(page: Page) {
const listeners = this.#listeners.get(page);
if (listeners) {
for (const [name, listener] of Object.entries(listeners)) {
page.off(name, listener as Handler<unknown>);
}
}
this.storage.delete(page);
}

getData(page: Page): T[] {
return this.storage.get(page) ?? [];
}
}

export class NetworkCollector extends PageCollector<HTTPRequest> {
override cleanup(page: Page) {
override cleanupAfterNavigation(page: Page) {
const requests = this.storage.get(page) ?? [];
if (!requests) {
return;
Expand Down
83 changes: 63 additions & 20 deletions tests/PageCollector.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import {describe, it} from 'node:test';

import type {Browser, Frame, Page, Target} from 'puppeteer-core';

import type {ListenerMap} from '../src/PageCollector.js';
import {PageCollector} from '../src/PageCollector.js';

import {getMockRequest} from './utils.js';
Expand All @@ -22,6 +23,9 @@ function mockListener() {
listeners[eventName] = [listener];
}
},
off(_eventName: string, _listener: (data: unknown) => void) {
// no-op
},
emit(eventName: string, data: unknown) {
for (const listener of listeners[eventName] ?? []) {
listener(data);
Expand Down Expand Up @@ -55,10 +59,12 @@ describe('PageCollector', () => {
const browser = getMockBrowser();
const page = (await browser.pages())[0];
const request = getMockRequest();
const collector = new PageCollector(browser, (page, collect) => {
page.on('request', req => {
collect(req);
});
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();
page.emit('request', request);
Expand All @@ -71,10 +77,12 @@ describe('PageCollector', () => {
const page = (await browser.pages())[0];
const mainFrame = page.mainFrame();
const request = getMockRequest();
const collector = new PageCollector(browser, (page, collect) => {
page.on('request', req => {
collect(req);
});
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();
page.emit('request', request);
Expand All @@ -89,10 +97,12 @@ describe('PageCollector', () => {
const browser = getMockBrowser();
const page = (await browser.pages())[0];
const request = getMockRequest();
const collector = new PageCollector(browser, (page, collect) => {
page.on('request', req => {
collect(req);
});
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();
page.emit('request', request);
Expand All @@ -106,10 +116,12 @@ describe('PageCollector', () => {
const page = (await browser.pages())[0];
const mainFrame = page.mainFrame();
const request = getMockRequest();
const collector = new PageCollector(browser, (page, collect) => {
page.on('request', req => {
collect(req);
});
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();
page.emit('request', request);
Expand All @@ -128,10 +140,12 @@ describe('PageCollector', () => {
const browser = getMockBrowser();
const page = (await browser.pages())[0];
const request = getMockRequest();
const collector = new PageCollector(browser, (pageListener, collect) => {
pageListener.on('request', req => {
collect(req);
});
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();
browser.emit('targetcreated', {
Expand All @@ -153,4 +167,33 @@ describe('PageCollector', () => {

assert.equal(collector.getData(page).length, 2);
});

it('should clear data on page destroy', async () => {
const browser = getMockBrowser();
const page = (await browser.pages())[0];
const request = getMockRequest();
const collector = new PageCollector(browser, collect => {
return {
request: req => {
collect(req);
},
} as ListenerMap;
});
await collector.init();

page.emit('request', request);

assert.equal(collector.getData(page).length, 1);

browser.emit('targetdestroyed', {
page() {
return Promise.resolve(page);
},
} as Target);

// The page inside part is async so we need to await some time
await new Promise<void>(res => res());

assert.equal(collector.getData(page).length, 0);
});
});