Imhotep/packages/imhotep-playwright/src/page-pool.test.ts

/**
 * Tests for the PagePool module.
 *
 * Uses mock BrowserContext and Page objects to verify pooling,
 * borrowing, returning, resetting, and disposal behavior.
 */

import { describe, it } from 'node:test'
import assert from 'node:assert'
import type { Page, BrowserContext } from 'playwright'
import { PagePool, PageEntry, ContextPool } from './page-pool.js'

function createMockContext(): BrowserContext & Record<string, any> {
  const context: any = {
    newPageCalls: 0,
    clearCookiesCalls: 0,
    closeCalls: 0,
    createdPages: [],
    newPage: async () => {
      context.newPageCalls++
      const page = createMockPage(context)
      context.createdPages.push(page)
      return page
    },
    clearCookies: async () => {
      context.clearCookiesCalls++
    },
    close: async () => {
      context.closeCalls++
    },
  }
  return context as BrowserContext & Record<string, any>
}

function createMockPage(context?: any): Page & Record<string, any> {
  const page: any = {
    gotoCalls: [],
    evaluateCalls: 0,
    setViewportSizeCalls: [],
    closeCalls: 0,
    goto: async (url: string) => {
      page.gotoCalls.push(url)
    },
    context: () => context,
    evaluate: async () => {
      page.evaluateCalls++
    },
    setViewportSize: async (size: any) => {
      page.setViewportSizeCalls.push(size)
    },
    close: async () => {
      page.closeCalls++
    },
    addInitScript: async () => {},
  }
  return page as Page & Record<string, any>
}

describe('PagePool', () => {
  it('warm creates specified number of pages', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    await pool.warm(context, 3)

    assert.strictEqual(context.newPageCalls, 3)

    const entries: PageEntry[] = (pool as any).pools.get(context) ?? []
    assert.strictEqual(entries.length, 3)
    assert.strictEqual(entries.every((e) => !e.inUse), true)
  })

  it('borrow returns warmed page', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    await pool.warm(context, 1)
    const entriesBefore: PageEntry[] = (pool as any).pools.get(context) ?? []
    const warmedPage = entriesBefore[0].imhotepPage

    const borrowed = await pool.borrow(context)

    assert.strictEqual(borrowed, warmedPage)

    const entriesAfter: PageEntry[] = (pool as any).pools.get(context) ?? []
    assert.strictEqual(entriesAfter[0].inUse, true)
  })

  it('borrow creates new page when none available', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    const borrowed = await pool.borrow(context)

    assert.strictEqual(context.newPageCalls, 1)
    assert.ok(borrowed)

    const entries: PageEntry[] = (pool as any).pools.get(context) ?? []
    assert.strictEqual(entries.length, 1)
    assert.strictEqual(entries[0].inUse, true)
  })

  it('borrow throws when at maxPagesPerContext and all in use', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool, { maxPagesPerContext: 2 })

    await pool.borrow(context)
    await pool.borrow(context)

    await assert.rejects(
      async () => pool.borrow(context),
      /Max pages per context \(2\) reached and all pages are in use/
    )
  })

  it('return resets page and marks available', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    const borrowed = await pool.borrow(context)
    const mockPage = context.createdPages[0]

    // Reset was called once during borrow
    assert.strictEqual(mockPage.evaluateCalls, 1)

    await pool.return(borrowed)

    // Return called reset again
    assert.strictEqual(mockPage.evaluateCalls, 2)

    const entries: PageEntry[] = (pool as any).pools.get(context) ?? []
    assert.strictEqual(entries[0].inUse, false)
  })

  it('reset clears cookies and localStorage', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    await pool.borrow(context)
    const mockPage = context.createdPages[0]

    assert.strictEqual(mockPage.gotoCalls.includes('about:blank'), true)
    assert.strictEqual(context.clearCookiesCalls, 1)
    assert.strictEqual(mockPage.evaluateCalls, 1)
    assert.deepStrictEqual(mockPage.setViewportSizeCalls, [{ width: 1280, height: 720 }])
  })

  it('dispose closes all pages', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    await pool.warm(context, 2)
    await pool.dispose()

    assert.strictEqual(context.createdPages[0].closeCalls, 1)
    assert.strictEqual(context.createdPages[1].closeCalls, 1)
  })

  it('idempotent dispose', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool)

    await pool.warm(context, 1)
    await pool.dispose()
    await pool.dispose()

    assert.strictEqual(context.createdPages[0].closeCalls, 1)
  })

  it('borrowed page is inUse', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool, { maxPagesPerContext: 1 })

    await pool.warm(context, 1)
    await pool.borrow(context)

    await assert.rejects(
      async () => pool.borrow(context),
      /Max pages per context \(1\) reached and all pages are in use/
    )
  })

  it('returned page is not inUse', async () => {
    const context = createMockContext()
    const pool = new PagePool({} as ContextPool, { maxPagesPerContext: 1 })

    await pool.warm(context, 1)
    const first = await pool.borrow(context)
    await pool.return(first)

    const second = await pool.borrow(context)

    assert.strictEqual(context.newPageCalls, 1)
    assert.strictEqual(second, first)
  })
})