Sebastian "Sebbie" Silbermann

This commit **refactors the TypeScript compiler's command-line parsing** to deemphasize the legacy `react` JSX transform. It reorders the `jsxOptionMap` in `src/compiler/commandLineParser.ts` so that `react-jsxdev` appears before `react`, subtly guiding users towards modern JSX transforms. This **maintenance and refactoring** change primarily affects **user-facing error messages and help output** for the `--jsx` compiler option. Baseline tests have been updated to reflect the new order of suggested arguments when an invalid `--jsx` option is provided, ensuring consistency in compiler diagnostics.

This commit **updates the default JSX emit configuration** within the **TypeScript language features extension**, specifically for inferred project compiler options. It changes the default value for the `jsx` setting in `inferredProjectCompilerOptions` from `'react'` to `'react-jsx'`, effectively **deemphasizing the older JSX transform**. This **feature update** ensures that new or unconfigured TypeScript projects will automatically leverage the modern `react-jsx` transform. The change aligns the default behavior with current React best practices, potentially offering improved build performance and reduced bundle sizes for affected projects.

This commit **skips a flaky E2E test suite** for **`segment-cache-refresh`** within the `app-dir` testing environment. By adding `.skip` to the `describe` block in `test/e2e/app-dir/segment-cache/refresh/segment-cache-refresh.test.ts`, this **test maintenance** change temporarily disables the suite. This action prevents intermittent CI failures caused by the unreliable test, ensuring a more stable testing pipeline. The functionality covered by this specific E2E test will not be validated until the suite is re-enabled.

This commit **temporarily disables end-to-end tests** for the **`app-dir` segment cache's `unstable_dynamicStaleTime` feature** due to observed flakiness. Specifically, the `segment-cache-per-page-dynamic-stale-time.test.ts` suite is now skipped to prevent intermittent CI failures. This **test maintenance** action improves pipeline stability, with a `TODO` comment added to `page.tsx` to remind developers to re-enable these tests once the feature is stable.

This commit introduces a **new feature** to the **Next.js FTL (File-system-based Type-safe Linking)** system, enhancing the generated route types. It modifies the **route type generation** process within `packages/next/src/server/lib/router-utils/typegen.ts` to embed the **source file path** as a comment directly into the output. This **enhancement**, implemented by refactoring `serializeRouteTypes` and `generateLinkTypesFile`, provides developers with better traceability and understanding of where each route type originates. The change improves the overall developer experience by making the generated type definitions more informative and easier to debug within the **router utilities**.

This commit introduces a **new capability** to the **Next.js development error overlay**, enabling it to properly display the individual errors contained within an `AggregateError`. A new `ErrorAggregateErrors` component is integrated into the `RuntimeError` display, along with updated error parsing logic in `getErrorByType` to extract and process these aggregate errors. This enhancement significantly improves the **developer experience** by providing clearer insights into complex runtime issues, making debugging more efficient. Extensive **test cases** have been added to validate the correct parsing and display of `AggregateError` instances, including those with nested causes and mixed error types.

This commit **de-flakes** the **`instant-navs-devtools` test suite** within the **`app-dir` development environment**. It addresses intermittent failures by adjusting the element selection logic in the `clickStartClientNav` function within `test/development/app-dir/instant-navs-devtools/instant-navs-devtools.test.ts`. A timeout has been added to the element selection, ensuring that the test reliably waits for the necessary DOM elements to be present before proceeding. This **test maintenance** improves the stability of CI/CD pipelines and provides more consistent feedback on the `instant-navs-devtools` feature.

This commit introduces a **new feature** to the **Next.js DevTools**, making the **instant navs panel** within the **dev overlay** fully **draggable**. It modifies the `PanelRouter` component in `packages/next/src/next-devtools/dev-overlay/menu/panel-router.tsx` to implement this functionality. Additionally, it includes configuration for sharing the panel's position, enhancing the persistence of user preferences. This improvement significantly boosts the **developer experience** by allowing users to customize and organize their dev tools workspace more efficiently.

This commit **enhances the Continuous Integration (CI) workflow** by extending the retention period for a critical artifact. Specifically, the `.github/workflows/build_and_test.yml` configuration is updated to retain the `test-timings` artifact for **5 days**, an increase from the previous 1-day limit. This **maintenance** change directly supports the ability to **"rerun failed jobs"** by ensuring the necessary timing data remains available for a longer duration. The increased retention period improves developer productivity and debugging capabilities within the **CI pipeline**.

This commit introduces the **capability to allow locking during manual React synchronization**, providing enhanced control over the `react-sync` process. As part of this effort, it **refactors** the `packages/next/taskfile.js` to prevent duplicate channel suffixes when overriding package names via the `copy_vendor_react` task's `overridePackageName` symbol. This ensures cleaner and more reliable package naming for **vendor React packages**, contributing to the overall stability and integrity of the **React synchronization mechanism**. The change improves the robustness of how these packages are managed and integrated into the project.

This commit **enhances the instant navigation testing lock** by introducing unique IDs into the instant navigation cookie values, ensuring distinct and reliable test execution. It **refactors** the core **instant navigation logic** within `packages/next/src/client` and updates the **Next.js DevTools overlay** to support this new cookie format. Additionally, it includes **Playwright dependency updates** and **test infrastructure improvements** to facilitate these changes, ultimately improving the robustness of instant navigation tests.

This commit focuses on **deflaking instant navigation tests** within the `app-dir` development environment, specifically for `instant-navs-devtools`. It introduces a new helper function, `waitForInstantModeCookie`, and integrates it into `clickStartClientNav` to ensure the instant mode cookie is properly set before client-side navigation. Additionally, logic is added to warm up target page compilation, further enhancing the stability of these critical **instant navigation tests** by preventing race conditions and improving test reliability.

This commit **enhances Playwright's WebSocket tracing** by implementing `TextDecoder` to properly decode and display **binary WebSocket messages**. Specifically, the `test/lib/browsers/playwright.ts` file is modified to process these messages, which previously appeared as unreadable byte arrays. This **test improvement** significantly **improves the readability of test traces** when debugging binary WebSocket communication. The change also includes simplified console logging, making it easier for developers to understand network interactions during test execution.

This commit performs **test maintenance** and **refactoring** within the **instant navigation devtools testing suite**. It introduces a new helper function, `hasInstantNavPanelOpen`, in `test/development/app-dir/instant-navs-devtools/instant-navs-devtools.test.ts` to reliably check the open state of the instant navigation panel. Existing test assertions are updated to utilize this more robust helper, resolving stale merge issues and improving the stability and clarity of tests for the **`app-dir` instant navigation feature**. This is a **test-only change** that ensures better validation of this development tool without affecting production code.

This commit **de-flakes** the **instant navigation devtools tests** by refactoring several test helper functions, such as `waitForPanelRouterTransition` and `clickInstantNavMenuItem`, and updating the overall test logic. These changes specifically target the test suite for the **instant navigation feature** within the `app-dir` development environment, significantly improving its reliability and stability. Additionally, a new `tsconfig.json` is introduced to provide a dedicated TypeScript configuration for this test directory, enhancing the **test infrastructure**. This **test maintenance and refactoring** ensures more consistent and accurate validation of the instant navigation functionality.

This commit **enhances the Playwright tracing integration** within the test suite by **improving the logging of `framereceived` payloads**. It modifies `test/lib/browsers/playwright.ts` to properly stringify these event payloads, ensuring they are recorded in a readable and useful format. This **test infrastructure improvement** is a **debugging enhancement** that provides **better visibility and analysis capabilities** for frame-related events during Playwright-driven tests. The change makes it significantly easier to diagnose and understand issues related to frame reception within the browser automation tests.

This commit **updates** the **vendored `json-schema-types` dependency** to a newer version. This **maintenance** task is essential for ensuring **compatibility with TypeScript 6.0**, as previous versions of the library shipped with TypeScript source files instead of the required declaration files. The update resolves potential build and type-checking issues, allowing the project to integrate seamlessly with the latest TypeScript compiler and tooling.

This commit performs a **dependency update** for the **`create-next-app`** package, specifically bumping the vendored `picocolors` library from version 1.0.0 to 1.1.1. This **maintenance** task is essential to ensure **compatibility with TypeScript 6.0**, as the previous version of `picocolors` was not compatible. By updating `packages/create-next-app/package.json`, this change prevents potential build or runtime issues for users leveraging `create-next-app` with newer TypeScript versions.

This commit implements a **testing infrastructure improvement** by **disabling test-level retries** specifically during **flakiness detection**. It introduces the `NEXT_FLAKE_DETECTION` environment variable, configured in `scripts/test-new-tests.mjs`, to activate this behavior. When this variable is set, the `test/lib/e2e-utils/index.ts` module will **prevent Jest from retrying failed tests**, ensuring that intermittent failures are accurately identified as flakes. This change is crucial for more precise and efficient **test flakiness analysis**, preventing retries from masking true flakiness.

This commit **enhances the `next-swc` transforms** by integrating **configurable page extensions** from the Next.js configuration. It **refactors various client-side and server-side transforms**, including those for **React Server Components**, **Debug Instant Stack**, and **Strip Page Exports**, to dynamically recognize and match page files based on these extensions. This **feature** allows `next-swc` to correctly process pages and layouts using custom or non-standard file extensions. The change improves the **flexibility and robustness** of the Next.js build process, ensuring transforms apply accurately across diverse project setups.