[major-43-regression] Major release regression branch

.github/workflows/_build.yml

@@ -105,6 +105,56 @@ jobs:
           name: ${{env.BUILD_LOGS}}
           path: ${{env.BUILD_LOGS}}.tar.br
 
+  React19:
+    # Forward-compatibility check: install React 19 + types into the cached
+    # node_modules (no save) and run typecheck + jest. Allowed to fail while
+    # the migration lands; flip to required once Repo 1 (backpack-web) is
+    # released and consumers can opt in.
+    runs-on: ubuntu-latest
+    needs: Build
+    continue-on-error: true
+    permissions:
+      statuses: write
+      pull-requests: write
+
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
+        with:
+          node-version-file: '.nvmrc'
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Restore Cache
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        id: npm-cache
+        with:
+          path: |
+            node_modules/
+            packages/node_modules/
+          key: ${{ env.CACHE_NAME }}-${{ hashFiles('package-lock.json', 'packages/package-lock.json') }}
+
+      - name: Override React to 19.2.5
+        # The inner packages/node_modules tree has its own copy of react/react-dom
+        # populated from the cache. Overlay the root install into it so jest
+        # (which resolves react-dom from packages/) sees R19 too.
+        run: |
+          npm install --no-save react@19.2.5 react-dom@19.2.5 @types/react@19 @types/react-dom@19 @types/prop-types
+          rm -rf packages/node_modules/react packages/node_modules/react-dom
+          cp -r node_modules/react packages/node_modules/
+          cp -r node_modules/react-dom packages/node_modules/
+
+      - name: Generate component code (icons, flare, spinners)
+        run: npm run build:gulp
+
+      - name: Run typecheck (React 19)
+        run: npm run typecheck
+
+      - name: Run jest (React 19)
+        run: TZ=Etc/UTC npm run jest
+
   Danger:
     runs-on: ubuntu-latest
     needs: Build

.github/workflows/main.yml

@@ -179,6 +179,10 @@ jobs:
           private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
 
       - name: Draft release notes
-        uses: release-drafter/release-drafter@6db134d15f3909ccc9eefd369f02bd1e9cffdf97 # v6.2.0
-        env:
-          GITHUB_TOKEN: ${{ steps.app-token.outputs.token }}
+        uses: release-drafter/release-drafter@563bf132657a13ded0b01fcb723c5a58cdd824e2 # v7.2.1
+        # release-drafter v7 no longer reads the GITHUB_TOKEN env var; the
+        # token must be passed via the `token` input or it falls back to the
+        # default `github.token`, which lacks the GitHub App permissions we
+        # rely on for drafting releases.
+        with:
+          token: ${{ steps.app-token.outputs.token }}

REACT_19_MIGRATION.md

@@ -0,0 +1,73 @@
+# React 19 Migration — `@skyscanner/backpack-web`
+
+(This repo is **Repo 1 of 5** in the Skyscanner shared-library React 19 pre-release codemod pass.)
+
+## What this thread should do
+
+1. Read the master plan's "Repo 1" section. It contains the full audit baseline, recipe checklist, and empty result fields to fill in.
+2. Execute the recipe inside this directory.
+3. As you progress, update the master plan's Repo 1 section with results (codemod diff summary, test outcomes, surprises).
+4. When done, append a one-paragraph "Surprises / runbook insights" entry, and open follow-up PRs against `web-documentation` and `web-migration-scripts` if any reusable insights came out.
+
+## Audit baseline (2026-05-05) — corrected after re-audit on 2026-05-05
+
+The original baseline overstated several categories. Re-audit confirmed:
+
+- Lerna-style monorepo, published from `packages/package.json`
+- React peerDep: `17.0.2 - 18.3.1` → narrowed-and-shifted to `18.3.1 - 19.2.5` (We shouldn't have any consumers below 18)
+- `static defaultProps` / `defaultProps =`: **84 files** (manual sweep, no codemod)
+- `forwardRef`: 14 files (none combined with `defaultProps`)
+- `prop-types` imports: **67 files** (mostly `.js`; manual conversion — see runbook insight below)
+- `act` from `react-dom/test-utils`: **0** (audit said 7; re-grep finds none)
+- `ReactDOM.render` / `hydrate`: **0** (audit said 1; the only hit is example text inside a `<BpkCodeBlock>` JSX literal in `BpkCode.stories.tsx`, not a real call)
+- String refs (`ref="..."`): **0**
+- `findDOMNode`: **0**
+- Legacy context API (`childContextTypes` / `getChildContext`): **0**
+- `useFormState`: **0**
+- Zero-arg `useRef()`: 0
+- TS 5.9.2; `@types/react` 18.3.1
+- Tests: Jest + `@testing-library/react` 16.3.0
+- CI: `.github/workflows/{release,pr,main}.yml` — `npm publish` after transpile
+
+### Runbook insight: `react/19/migration-recipe` is destructive on this codebase
+
+Dry-running `react/19/migration-recipe` (codemod 1.9.1, which silently invokes legacy codemod 0.18.13) on backpack:
+
+- **Strips Apache 2.0 license headers** from every modified file. Backpack requires these.
+- Generates **wrong TypeScript interfaces** when files already have proper TS types (e.g. `BpkBasicMapMarker.tsx` keeps the existing `type Props = { children: ReactNode, position: LatLong }` orphaned and points the component at a new redundant `interface { ...; position: unknown }`).
+- Only matched **6 of 67** prop-types files in this repo despite the recipe including `prop-types-typescript`.
+
+We are skipping the bundled recipe. The four mechanical sub-codemods (`replace-act-import`, `replace-reactdom-render`, `replace-string-ref`, `replace-use-form-state`) all dry-run as 0-changes here, so they are also skipped. Only `types-react-codemod` (TS-types only, much narrower scope) is being run.
+
+The `prop-types` and `defaultProps` migrations are being done with a custom jscodeshift transform tailored to backpack, preserving license headers and faithful types.
+
+### Runbook insight: peerDep range narrowed instead of widened
+
+Our intention is to **drop React 17 support** as part of this PR, to `18.3.1 - 19.2.5`. React 17 is unsupported upstream, no consumer is still on it, and dropping it shrinks the test/CI matrix surface.
+
+## Recipe summary — adapted for this repo
+
+1. [x] Pin `codemod` + `types-react-codemod` as devDeps with `--save-exact` (no `npx`/`pnpm dlx` — Skyscanner Security stance).
+2. [x] ~~`react/19/migration-recipe`~~ — **skipped** (destructive on this codebase; see runbook insight above).
+3. [x] ~~Individual mechanical codemods~~ — **skipped** (dry-runs as 0-changes for all four).
+4. [x] `types-react-codemod preset-19` — applied with `refobject-defaults` and `useRef-required-initial` excluded (those two only typecheck against `@types/react@19`; deferred to the future `@types/react` bump PR).
+5. [x] `types-react-codemod react-element-default-any-props` — confirmed no-op (already covered by preset-19).
+6. [x] Custom jscodeshift transform applied (`scripts/react-19/transforms/strip-proptypes.js`, see scripts/react-19/README.md). Touched 27 files: removed prop-types from `.tsx`, migrated function-component `.defaultProps` to ES6 destructure defaults across `.js` and `.tsx`. License headers preserved.
+7. [x] Manual cleanup of edge cases the transform left (1 eslint-disable + 2 dead-import removals).
+8. [x] `forwardRef` ref-callback implicit-return scan — 0 issues, all 14 sites use block-body callbacks.
+9. [x] Update `peerDependencies` in `packages/package.json` to `18.3.1 - 19.2.5` (drops React 17, adds 19; range syntax matching the existing peerDep style).
+10. [x] Add CI matrix entry running tests against React 19.2.5 (`continue-on-error: true` initially).
+11. [x] Uninstall codemod packages.
+12. [ ] Coordinate version bump with the Backpack team.
+
+## Deferred to follow-up PRs
+
+The current PR establishes the scaffolding (peerDep range, CI matrix, codemod tooling, `.tsx` prop-types/defaultProps cleanup). The following items land in separate PRs:
+
+- **35 class components with `static defaultProps`** (27 `.tsx` + 8 `.js`) — React 19 makes these no-ops, so defaults silently stop applying. Each needs either conversion to a functional component (preferred) or destructure-with-defaults inside `render()` (quick fix). See the React19 CI matrix output for the failure surface; group by package to keep PRs reviewable.
+- **13 `.js` story/HOC files with leftover `Component.defaultProps = ...`** — Phase B of the transform couldn't merge defaults because the function bodies are implicit-return arrows or otherwise ineligible. React 19 silently ignores these.
+- **`.js` (Flow) prop-types removal** — intentionally skipped by the transform because the project's `react/prop-types` lint rule treats removed prop-types as missing prop validation on `.js` files. Full removal happens during the parallel TS migration; React 19 ignores `propTypes` silently in the meantime.
+- **`@types/react@19` bump** — running `types-react-codemod preset-19`'s `refobject-defaults` and `useRef-required-initial` sub-transforms together with bumping `@types/react` to 19. These were skipped here because they emit code that only typechecks against `@types/react@19`.
+- **Track and fix the React19 CI matrix failures** — typecheck has 8 known errors (the deferred sub-transforms above plus a missing `@types/prop-types`), and jest has 326 suite failures (mostly transitive deps still using removed React 18 internals like `ReactCurrentDispatcher`). Once green, flip the matrix from `continue-on-error: true` to required.
+- **Move the custom transform to `web-migration-scripts/migrations/2026-05-react-19/transforms/`** when that migration directory is set up.
+

libs/backpack-storybook-utils/src/BpkDarkExampleWrapper.js

@@ -24,7 +24,7 @@ import STYLES from './BpkDarkExampleWrapper.module.scss';
 const getClassName = cssModules(STYLES);
 
 const BpkDarkExampleWrapper = (props: { padded: boolean }) => {
-  const { padded, ...rest } = props;
+  const { padded = false, ...rest } = props;
   return (
     /* $FlowFixMe[cannot-spread-inexact] - inexact rest. See 'decisions/flowfixme.md'. */
     <div
@@ -37,8 +37,4 @@ const BpkDarkExampleWrapper = (props: { padded: boolean }) => {
   );
 };
 
-BpkDarkExampleWrapper.defaultProps = {
-  padded: false,
-};
-
 export default BpkDarkExampleWrapper;