Move duplicated adapter code into core

The same logic sat in two or three adapters word for word, so a change to it
had to land in every copy, which is CLAUDE.md's rule for core:

- The screencast recorder's start, stop and unavailable log lines were
  written by each adapter's subclass; ScreencastRecorderBase now writes
  them through a logger each adapter supplies, keeping its logger name.
- Selenium and Nightwatch built their BiDi console and network sinks the
  same way; buildBidiSinks is now in core, with Selenium's console
  evidence latch passed in as a hook, since only Selenium has one.

Within one adapter: Selenium's mocha, cucumber and jest hooks share one run
summary; Selenium's and Nightwatch's PluginInternals extend the context
types they repeated; Nightwatch builds its captured and replaced command
rows through one helper; the WDIO launcher and standalone mode share their
argv parsing, in a module of its own so the launcher's rerun patch never
reaches the worker bundle.

Kept: each adapter's attachBidiHandlers only binds its own logger name, and
the types.ts files re-export shared types under stable local names.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: vishnuv688

packages/core/src/bidi.ts

@@ -12,17 +12,50 @@ import {
 import { errorMessage } from './error.js'
 import { getRequestType } from './net.js'
 
-/**
- * Generic sinks the BiDi handlers push into. Each adapter wires these to its
- * own SessionCapturer state — selenium's `buildBidiSinks` is the canonical
- * example; nightwatch can mirror the pattern when it wires up BiDi.
- */
+/** Generic sinks the BiDi handlers push into; {@link buildBidiSinks} wires them to a capturer. */
 export interface BidiHandlerSinks {
   pushConsoleLog: (entry: ConsoleLog) => void
   pushNetworkRequest: (entry: NetworkRequest) => void
   replaceNetworkRequest: (id: string, entry: NetworkRequest) => void
 }
 
+/** The capturer state BiDi events land in; `bidiNetworkObserved` is the evidence latch that gates the page's own rows. */
+export interface BidiSinkTarget {
+  consoleLogs: ConsoleLog[]
+  networkRequests: NetworkRequest[]
+  sendUpstream(event: string, data: unknown): void
+  bidiNetworkObserved: boolean
+}
+
+/** Route BiDi events into the target's arrays and upstream; `onConsoleEntry` runs before each console entry is kept. */
+export function buildBidiSinks(
+  target: BidiSinkTarget,
+  onConsoleEntry?: () => void
+): BidiHandlerSinks {
+  return {
+    pushConsoleLog: (entry) => {
+      onConsoleEntry?.()
+      target.consoleLogs.push(entry)
+      target.sendUpstream('consoleLogs', [entry])
+    },
+    pushNetworkRequest: (entry) => {
+      target.bidiNetworkObserved = true
+      target.networkRequests.push(entry)
+      target.sendUpstream('networkRequests', [entry])
+    },
+    replaceNetworkRequest: (id, entry) => {
+      target.bidiNetworkObserved = true
+      const idx = target.networkRequests.findIndex((r) => r.id === id)
+      if (idx !== -1) {
+        target.networkRequests[idx] = entry
+      } else {
+        target.networkRequests.push(entry)
+      }
+      target.sendUpstream('networkRequests', [entry])
+    }
+  }
+}
+
 /**
  * Resolve a `selenium-webdriver/<subpath>` module from the user's install
  * (preferred) or the package's local install (fallback). Returns `null` if

packages/core/src/screencast.ts

@@ -2,6 +2,7 @@ import type { ScreencastFrame, ScreencastOptions } from '@wdio/devtools-shared'
 import { SCREENCAST_DEFAULTS } from '@wdio/devtools-shared'
 import { isInputDispatchInFlight } from './input-dispatch.js'
 import { withTimeout } from './with-timeout.js'
+import { errorMessage } from './error.js'
 
 /** Ceiling for one awaited driver primitive in the screencast start/stop
  *  handshake. The queue serialises start against stop, so a primitive that
@@ -10,6 +11,12 @@ export const SCREENCAST_HANDSHAKE_TIMEOUT_MS = 5000
 
 const FIRST_SHOT_TIMEOUT = Symbol('first-shot-timeout')
 
+/** Where a recorder reports its lifecycle; each adapter passes its own logger. */
+export interface ScreencastLogger {
+  info(message: string): void
+  warn(message: string): void
+}
+
 /**
  * Shared screencast scaffolding consumed by every adapter (service, selenium,
  * nightwatch). Owns the frame buffer, public API (start/stop/setStartMarker,
@@ -235,22 +242,26 @@ export abstract class ScreencastRecorderBase<TDriver = unknown> {
 
   // ─── Polling implementation ─────────────────────────────────────────────
 
-  /**
-   * Hook fired when the polling loop starts. Default: no-op. Subclasses
-   * (adapters with their own logger) override to surface visibility.
-   */
-  protected onPollingStarted(_intervalMs: number): void {
-    // no-op
+  /** The adapter's logger for the hooks below; none keeps them silent. */
+  protected readonly logger: ScreencastLogger | undefined = undefined
+
+  /** Hook fired when the polling loop starts. */
+  protected onPollingStarted(intervalMs: number): void {
+    this.logger?.info(
+      `✓ Screencast recording started (polling mode, ${intervalMs} ms interval)`
+    )
   }
 
   /** Hook fired when polling stops cleanly (driver still alive at the time). */
-  protected onPollingStopped(_frameCount: number): void {
-    // no-op
+  protected onPollingStopped(frameCount: number): void {
+    this.logger?.info(`✓ Screencast stopped — ${frameCount} frame(s) collected`)
   }
 
   /** Hook fired when the polling fallback couldn't even take the first shot. */
-  protected onUnavailable(_err: unknown): void {
-    // no-op
+  protected onUnavailable(err: unknown): void {
+    this.logger?.warn(
+      `Screencast unavailable (${errorMessage(err)}). Recording skipped.`
+    )
   }
 
   // ─── Polling implementation ─────────────────────────────────────────────

packages/core/tests/bidi.test.ts

@@ -2,6 +2,8 @@ import { describe, it, expect } from 'vitest'
 import {
   arrayHeadersToObject,
   attachBidiHandlers,
+  buildBidiSinks,
+  type BidiSinkTarget,
   loadSeleniumSubmodule,
   handleBidiConsoleEntry,
   handleBidiJsException,
@@ -670,3 +672,72 @@ describe('attachNetworkInspector with an inspector that has a fetchError hook',
     expect(replacements.at(-1)?.entry).toMatchObject({ id: 'open', status: 0 })
   })
 })
+
+describe('buildBidiSinks', () => {
+  function makeTarget() {
+    const sent: Array<[string, unknown]> = []
+    const target: BidiSinkTarget = {
+      consoleLogs: [],
+      networkRequests: [],
+      bidiNetworkObserved: false,
+      sendUpstream: (event, data) => sent.push([event, data])
+    }
+    return { target, sent }
+  }
+  const request = (id: string, url = 'https://x/'): NetworkRequest => ({
+    id,
+    url,
+    method: 'GET',
+    type: 'document',
+    timestamp: 1,
+    startTime: 0
+  })
+
+  it('keeps and forwards a console entry, calling the hook first', () => {
+    const { target, sent } = makeTarget()
+    const seen: number[] = []
+    const sinks = buildBidiSinks(target, () =>
+      seen.push(target.consoleLogs.length)
+    )
+    const entry = { type: 'log' as const, args: ['hi'], timestamp: 1 }
+    sinks.pushConsoleLog(entry)
+    expect(seen).toEqual([0])
+    expect(target.consoleLogs).toEqual([entry])
+    expect(sent).toEqual([['consoleLogs', [entry]]])
+    expect(target.bidiNetworkObserved).toBe(false)
+  })
+
+  it('accepts a console entry without a hook', () => {
+    const { target } = makeTarget()
+    buildBidiSinks(target).pushConsoleLog({
+      type: 'log',
+      args: ['hi'],
+      timestamp: 1
+    })
+    expect(target.consoleLogs).toHaveLength(1)
+  })
+
+  it('latches network evidence on a pushed request', () => {
+    const { target, sent } = makeTarget()
+    buildBidiSinks(target).pushNetworkRequest(request('a'))
+    expect(target.bidiNetworkObserved).toBe(true)
+    expect(target.networkRequests.map((r) => r.id)).toEqual(['a'])
+    expect(sent).toEqual([['networkRequests', [request('a')]]])
+  })
+
+  it('replaces a known request in place and appends an unknown one', () => {
+    const { target } = makeTarget()
+    const sinks = buildBidiSinks(target)
+    sinks.pushNetworkRequest(request('a'))
+    sinks.pushNetworkRequest(request('b'))
+    target.bidiNetworkObserved = false
+    sinks.replaceNetworkRequest('a', request('a', 'https://done/'))
+    sinks.replaceNetworkRequest('c', request('c'))
+    expect(target.bidiNetworkObserved).toBe(true)
+    expect(target.networkRequests.map((r) => [r.id, r.url])).toEqual([
+      ['a', 'https://done/'],
+      ['b', 'https://x/'],
+      ['c', 'https://x/']
+    ])
+  })
+})

packages/core/tests/screencast.test.ts

@@ -1,5 +1,8 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest'
-import { ScreencastRecorderBase } from '../src/screencast.js'
+import {
+  ScreencastRecorderBase,
+  type ScreencastLogger
+} from '../src/screencast.js'
 import {
   INPUT_DISPATCH_MAX_HOLD_MS,
   beginInputDispatch
@@ -540,3 +543,51 @@ describe('ScreencastRecorderBase — buffer cap / decimation', () => {
     await r.stop()
   })
 })
+
+describe('ScreencastRecorderBase: lifecycle logging', () => {
+  function makeLogger() {
+    const lines: Array<[string, string]> = []
+    const logger: ScreencastLogger = {
+      info: (m) => lines.push(['info', m]),
+      warn: (m) => lines.push(['warn', m])
+    }
+    return { logger, lines }
+  }
+
+  it('reports polling start and stop through the adapter logger', async () => {
+    const { logger, lines } = makeLogger()
+    class Logged extends TestRecorder {
+      protected override readonly logger = logger
+    }
+    const r = new Logged({ pollIntervalMs: 50 })
+    await r.start({ name: 'driver' })
+    await r.stop()
+    expect(lines).toEqual([
+      ['info', '✓ Screencast recording started (polling mode, 50 ms interval)'],
+      ['info', '✓ Screencast stopped — 1 frame(s) collected']
+    ])
+  })
+
+  it('warns with the cause when the first shot cannot be taken', async () => {
+    const { logger, lines } = makeLogger()
+    class Logged extends TestRecorder {
+      protected override readonly logger = logger
+    }
+    const r = new Logged({ pollIntervalMs: 50 })
+    r.shouldFailFirst = true
+    await r.start({ name: 'driver' })
+    expect(lines).toEqual([
+      [
+        'warn',
+        'Screencast unavailable (first screenshot returned null). Recording skipped.'
+      ]
+    ])
+  })
+
+  it('stays silent without a logger', async () => {
+    const r = new TestRecorder({ pollIntervalMs: 50 })
+    r.shouldFailFirst = true
+    await expect(r.start({ name: 'driver' })).resolves.toBeUndefined()
+    expect(r.isRecording).toBe(false)
+  })
+})

packages/nightwatch-devtools/src/bidi.ts

@@ -3,10 +3,11 @@ import {
   type BidiHandlerSinks,
   attachBidiHandlers as attachBidiHandlersCore
 } from '@wdio/devtools-core'
-import type { SessionCapturer } from './session.js'
 
 const log = logger('@wdio/nightwatch-devtools:bidi')
 
+export { buildBidiSinks } from '@wdio/devtools-core'
+
 /**
  * Nightwatch wrapper around the core BiDi attach helper. Nightwatch ships
  * selenium-webdriver under the hood (via chromedriver), so the same
@@ -25,34 +26,3 @@ export async function attachBidiHandlers(
     log[level](message)
   )
 }
-
-/**
- * Build sinks that route BiDi events into the SessionCapturer's local arrays
- * and broadcast them upstream. Mirrors selenium-devtools' `buildBidiSinks` —
- * separate per-adapter because the SessionCapturer concrete types differ.
- */
-export function buildBidiSinks(capturer: SessionCapturer): BidiHandlerSinks {
-  return {
-    pushConsoleLog: (entry) => {
-      capturer.consoleLogs.push(entry)
-      capturer.sendUpstream('consoleLogs', [entry])
-    },
-    pushNetworkRequest: (entry) => {
-      capturer.bidiNetworkObserved = true
-      capturer.networkRequests.push(entry)
-      capturer.sendUpstream('networkRequests', [entry])
-    },
-    replaceNetworkRequest: (id, entry) => {
-      capturer.bidiNetworkObserved = true
-      const idx = capturer.networkRequests.findIndex(
-        (r: { id?: string }) => r.id === id
-      )
-      if (idx !== -1) {
-        capturer.networkRequests[idx] = entry
-      } else {
-        capturer.networkRequests.push(entry)
-      }
-      capturer.sendUpstream('networkRequests', [entry])
-    }
-  }
-}

packages/nightwatch-devtools/src/cucumber-lifecycle.ts

@@ -64,6 +64,7 @@ export interface CucumberLifecycleCtx extends TestSliceCtx {
   setCurrentTest(t: unknown): void
   recordAttempt(uid: string, specFile?: string): number
   recordOutcome(uid: string, state: TestStats['state']): void
+  /** Produces (no attach) this test's screenshot and video, core-gated to trace mode and `test` granularity. */
   emitTestArtifacts(uid: string | undefined, failed: boolean): Promise<void>
 }