microsoft/playwright

Four concrete flows were followed through source: test startup/execution, browser launch, locator click, and storage save/restore. The traces below preserve execution order and significant conditions. Error handling, force behavior, and reuse modes change these paths. They describe source behavior rather than observed runtime executions.

• Test startup: cli.js → program.parse → addTestCommand action → runTests → overridesFromOptions → loadConfigFromFile → filterProjects; arguments after '--' are removed from file filters.
  packages/playwright/cli.js#L18-19packages/playwright/src/program.ts#L55-63packages/playwright/src/cli/testActions.ts#L27-48
• Ordinary test execution: runAllTestsWithConfig → createReporters/LastRunReporter → rebaseline/global-setup/load tasks → phase/report/run tasks → runTasks; list mode instead loads and reports without those execution tasks.
  packages/playwright/src/runner/testRunner.ts#L422-451packages/playwright/src/runner/tasks.ts#L155-169
• Worker scheduling: createRunTestsTask checks dependencies → Dispatcher.run allocates slots and schedules → _createWorker constructs WorkerHost → WorkerHost.start creates artifacts and starts the runner; workers receive groups through runTestGroup messages.
  packages/playwright/src/runner/tasks.ts#L435-459packages/playwright/src/runner/dispatcher.ts#L220-251packages/playwright/src/runner/workerHost.ts#L70-89
• Browser launch: client BrowserType.launch normalizes args/env → channel.launch → BrowserTypeDispatcher.launch checks denyLaunch → server BrowserType.launch validates options and chooses Selenium or _innerLaunchWithRetries → _innerLaunch.
  packages/playwright-core/src/client/browserType.ts#L66-82packages/playwright-core/src/server/dispatchers/browserTypeDispatcher.ts#L38-43packages/playwright-core/src/server/browserType.ts#L67-112
• Native launch continuation: _prepareToLaunch creates/selects directories and resolves the executable → _launchProcess calls launchProcess and waits for readiness → pipe/WebSocket transport → connectToTransport; persistent default-context preparation is skipped with ignoreAllDefaultArgs.
  packages/playwright-core/src/server/browserType.ts#L135-196packages/playwright-core/src/server/browserType.ts#L206-243packages/playwright-core/src/server/browserType.ts#L264-280
• Click: Locator.click delegates to its frame with strict:true → FrameDispatcher.click → server Frame.click → _retryWithProgressIfNotConnected → handle._click → _retryPointerAction → page.mouse.click; detached targets retry and force skips prechecks/visibility waits.
  packages/playwright-core/src/client/locator.ts#L117-119packages/playwright-core/src/server/dispatchers/frameDispatcher.ts#L147-149packages/playwright-core/src/server/frames.ts#L1200-1260packages/playwright-core/src/server/dom.ts#L548-553
• Storage save: client storageState → BrowserContextDispatcher.storageState → server storageState → injected StorageScript.collect on live or temporary pages → channel result → optional mkdir/writeFile on the client.
  packages/playwright-core/src/client/browserContext.ts#L471-477packages/playwright-core/src/server/dispatchers/browserContextDispatcher.ts#L336-337packages/playwright-core/src/server/browserContext.ts#L617-645packages/injected/src/storageScript.ts#L173-193
• Storage replacement: prepareStorageState → channel.setStorageState → dispatcher calls server mode 'api' → cache/cookie cleanup → cookie/credential restore → intercepted origin navigation and StorageScript.restore → temporary-page close; resetForReuse retains the page and removes its interceptor.
  packages/playwright-core/src/client/browserContext.ts#L480-483packages/playwright-core/src/server/dispatchers/browserContextDispatcher.ts#L340-341packages/playwright-core/src/server/browserContext.ts#L670-727packages/injected/src/storageScript.ts#L276-310