### What?
Converts every test under `test/integration/` to an isolated test
running through `nextTestSetup` (under `test/e2e/`, `test/production/`,
`test/development/`, or `test/unit/`), then deletes `test/integration/`
along with the legacy CI orchestration that was specific to it.
- `test/integration/` removed entirely (~327 test suites)
- New isolated suites added across the existing folders:
- `test/e2e/` — 175
- `test/production/` — 130
- `test/development/` — 43
- `test/unit/` — 1
- `.github/workflows/build_and_test.yml` and `run-tests.js` no longer
have any `integration` branches
- `nextTestSetup` gained a `baseUrl` option on `next.browser()` so a
small number of tests that drive their own proxy/static-export server
can keep using `next.browser(...)` instead of importing `next-webdriver`
directly
### Why?
`test/integration/` predated `nextTestSetup` and ran tests directly
against the source checkout via custom helpers (`launchApp`,
`nextBuild`, `nextStart`, `runNextCommand`, `webdriver`, `fetchViaHTTP`,
…). Each suite hand-rolled its own dev/start/build orchestration,
fixture mutation, and process management.
The isolated test model used by the rest of the repo gives each suite an
isolated working directory containing a packed `next.tgz` install, a
uniform `next.start()` / `next.build()` / `next.fetch()` /
`next.browser()` API, and the same lifecycle for dev, start, and deploy
modes — so a single set of assertions covers all three. Deploy-mode
skips and per-feature gates are expressed declaratively
(`skipDeployment`, `disableAutoSkewProtection`, `if (skipped) return`)
instead of branching on `process.env`.
Removing `test/integration/` lets us:
- Delete the bespoke orchestration code in the CI workflow and
`run-tests.js`
- Run every converted suite consistently in dev, start, and deploy modes
(where applicable)
- Reproduce every test locally with the same `pnpm
test-{dev,start}-{turbo,webpack}` commands; no separate `integration`
path
- Open the door to running `test/production` against deployments in the
future (the converted suites already declare `skipDeployment` so they
can be flipped on)
### How?
Mechanical conversion per suite, with targeted clean-ups:
1. **Per-suite conversion.** Each
`test/integration/<name>/test/index.test.{js,ts}` was rewritten into a
single `<name>.test.ts` under the right folder based on what the
original exercised:
- `launchApp` / dev-only assertions → `test/development/`
- `nextBuild` + `nextStart` / start-only assertions → `test/production/`
- Both → `test/e2e/`
- The one pure jsdom render check (`link-without-router`) → `test/unit/`
2. **API mapping.** Custom helpers were replaced by `nextTestSetup`
equivalents: `launchApp` → `next.start()`, `nextBuild` → `next.build()`,
`runNextCommand` → `next.runCommand`, `fetchViaHTTP` → `next.fetch`,
`webdriver(...)` → `next.browser(...)`. Fixture mutations switched from
raw `fs.writeFile`/`fs.rename` to `next.patchFile` (with the 3-arg
`runWithTempContent` callback when the change has a defined scope) and
`next.deleteFile`.
3. **Deploy-mode handling.** Suites that can't run in deploy mode (use
`patchFile` / `next.build()` / depend on local CLI output) declare
`skipDeployment: true` and early-return on the `skipped` boolean. Suites
where Vercel's edge mutates URLs (`&dpl=`, immutable assets) declare
`disableAutoSkewProtection: true`.
4. **`next.browser({ baseUrl })`.** A handful of tests
(`prerender-export`, `cdn-cache-busting`, `preload-viewport`, both
`react-virtualized` suites) need to drive a separate server (a
static-export server or an `http-proxy` instance) rather than the
Next.js process. Instead of importing `next-webdriver` directly, those
tests now pass `{ baseUrl: <port|url> }` to `next.browser()`. For the
proxy cases, the proxy was moved into `server.js` inside the fixture and
`http-proxy` declared via the `dependencies` option of `nextTestSetup`,
so the test runs with a fully isolated dependency graph.
5. **CI clean-up.** With `test/integration` gone, the `test
integration*` jobs and `integration-tests-manifest`-related logic in
`.github/workflows/build_and_test.yml` were removed, and `run-tests.js`
no longer has the `integration` test-folder branch.
6. **Validation.** The PR was iterated against multiple full CI runs;
the remaining failures on the latest run are pre-existing flakes
(segment-cache 60s `act` timeouts in turbopack-prod) or transient
infrastructure issues unrelated to the conversion.
## What?
When a webpack/turbopack loader produces broken code, error messages now
display **both** the original source and the generated code with source
map information, making it much easier to debug loader issues.
## Why?
Previously, when loaders returned invalid code, error messages only
showed the original source file (after source-map remapping). Users had
no way to see what the loader actually generated, making it hard to
diagnose why the code failed to parse. Showing both sides gives full
context about what went wrong.
## How?
### Turbopack Core (`turbopack-core`)
- **`Source::description()`** — New method on the `Source` trait
providing human-readable descriptions of where code comes from.
Implemented across all source types (`FileSource`, `VirtualSource`,
`WebpackLoadersProcessedAsset`, `PostCssTransformedAsset`, etc.),
producing chains like `"loaders [sass-loader] transform of file content
of ./styles.scss"`.
- **`AdditionalIssueSource`** — New struct to hold a labeled source
location. The `Issue` trait gains an `additional_sources()` method so
issues can expose supplementary code frames.
- **`GeneratedCodeSource`** — A wrapper that strips `GenerateSourceMap`
support from a source, ensuring the *generated* code is displayed as-is
rather than being remapped back to the original.
- **`IssueSource::to_generated_code_source()`** — Helper that detects
sources implementing `GenerateSourceMap` and wraps them in
`GeneratedCodeSource` for display. Used by `AnalyzeIssue` and
`ParsingIssue` to automatically attach generated code frames.
### Error Formatting
- **`turbopack-cli-utils`** — Renders additional sources in CLI issue
output.
- **`format-issue.ts`** — Renders additional sources in the browser
error overlay. Extracted `formatSourceCodeFrame()` helper to deduplicate
code-frame rendering between primary and additional sources.
- Long-line truncation (e.g. minified CSS from SCSS) is handled natively
by the Rust-based `codeFrameColumns` implementation.
### Type Definitions
- Added `SourcePosition`, `IssueSource`, and `AdditionalIssueSource`
interfaces to TypeScript types.
- Updated `PlainSource` (added `file_path`), `PlainIssue` (added
`additional_sources`), and NAPI bindings to pass the data through.
### Test Coverage
- **E2e tests** (`test/e2e/webpack-loader-parse-error/`) with custom
broken JS and CSS loaders, covering all 4 modes:
- **Development (Turbopack)** — Verifies parse errors show both original
and generated code via browser error overlay
- **Development (Webpack)** — Verifies error overlay shows the parse
error (webpack doesn't support additional sources)
- **Production (Turbopack)** — Verifies build failure output with full
error extraction and inline snapshots
- **Production (Webpack)** — Verifies build failure output with inline
snapshots
- Updated `test/development/sass-error/` snapshot to include the new
generated code frame for minified SCSS output.
### Example Output
When a loader produces broken code, users now see:
```
⨯ ./app/data.broken.js:3:1
Parsing ecmascript source code failed
1 | // This file will be processed by broken-js-loader
2 | // The loader will return invalid JavaScript with a source map
> 3 | export default function Data() {
| ^
4 | return <div>original source content</div>
5 | }
6 |
Expected '</', got '{'
Generated code of loaders [./broken-js-loader.js] transform of file content of app/data.broken.js:
./app/data.broken.js:3:46
1 | // Generated by broken-js-loader
2 | export default function Page() {
> 3 | return <div>this is intentionally broken {{{ invalid jsx
| ^
4 | }
5 |
Import trace:
Server Component:
./app/data.broken.js
./app/page.js
```
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Tobias Koppers <sokra@users.noreply.github.com>
Co-authored-by: Luke Sandberg <lukeisandberg@gmail.com>
Sebastian "Sebbie" Silbermann