web-abap2UI5

Live demo: abap2ui5.github.io/web-abap2UI5-build — the complete abap2UI5 backend, downported, transpiled to JavaScript and running inside your browser tab. No server, no SAP system.

The build is rebuilt daily from the current abap2UI5 and samples sources and deployed to web-abap2UI5-build (GitHub Pages). Contributor and agent guidance lives in AGENTS.md.

Functionality

• Downporting with abaplint
• Transpiling to JS with abaplint/transpiler
• Running on Node.js with open-abap
• Service exposing via express-icf-shim
• Running the same backend in the browser: webpack bundles the transpiled ABAP into one script and sql.js (SQLite compiled to wasm) stands in for the database, so the demo needs no server at all — it is a static GitHub Pages site

Tasks

Downport & Transpile

npm run clone
npm run build

Run Unit Tests

npm test          # clone once, then: downport + transpile + unit tests
npm run test:unit # only the transpiled unit tests, on an existing ./output

npm test is exactly what CI runs as "the tests".

Run Webservice

The transpiled backend on Node.js, served by express on port 3000. Started by hand — it is not part of any test run:

npm run serve:express

Webpack Build Strategy

1. Clone repositories into /src/
2. Downport /src/ into /downport/
3. Transpile with express-icf-shim into /output/
4. Webpack backend + database into folder build

npm run build:web

The bundle contains no static frontend copy: at runtime app/web.mjs initializes the transpiled backend, issues an in-memory HTTP GET against it (the same z2ui5_cl_http_handler GET that serves real systems, including the sap.ui.require.preload of the complete current UI5 frontend) and document.writes the returned page. Frontend and backend are therefore always the versions cloned that day. The backend's Content-Security-Policy meta tag is stripped from the written page — it is designed for server-served deployments (no unsafe-eval/wasm-unsafe-eval) and would break the wasm/eval-based in-browser runtime while protecting nothing here.

Test the build locally (webpack-dev-server HMR does not work with the document.write boot):

npm run serve:build

CI

The build_web workflow runs daily: it clones abap2UI5 and the top-level apps of samples, runs downport, transpile, unit tests and the webpack build, then smoke tests the built site in a real browser before deploying it to web-abap2UI5-build (GitHub Pages). Note: GitHub disables scheduled workflows after 60 days without repository activity — re-enable it under Actions if the demo stops updating.

The browser gate is the one that matters: everything upstream of it can be green while the deployed page is blank, because a bundling or initialization fault only shows when the bundle actually runs. tests/web.spec.js loads the freshly built ./build, waits for the in-browser backend to answer, and asserts an event roundtrip restores the saved draft. Before it existed, the site deployed completely untested.

npm run build:web   # build ./build
npm run test:e2e    # the same gate, locally (playwright, project chromium-web)

@abaplint/cli is pinned to the version used by abap2UI5 itself, since the downport result must pass the same syntax check. Dependabot is told to leave that pin alone — see .github/dependabot.yml.

The deploy is a production webpack build. Two Terser defaults have to be turned off for it (keep_classnames, keep_fnames) because the transpiled ABAP carries its type system in the class and function names that RTTI reads back — see the comment in webpack.config.js.

The deployed site is not only the bundle: app/pages/ (README, 404 page) and this repository's LICENSE are copied into ./build before the deploy, and the build's provenance is written as build-stamp.txt plus a human-readable BUILD_INFO.json. The deploy runs with force_orphan: true, so anything committed in the artifact repository by hand is gone with the next run — every file that should be there has to be produced here.

Limitations & Todo

• Samples in subfolders of the samples repository (system samples, launchpad samples) are excluded — they require a real SAP system and cannot be transpiled
• src/99 of abap2UI5 (the frozen legacy package) is not part of the build. clone:core drops it. Should a sample ever need one of those classes again, the fix belongs in the sample — src/99 is on abap2UI5's removal plan and will not be there forever
• A known upstream @abaplint/transpiler issue makes check_on_init( ) always false in the transpiled backend (interface attributes read through an interface-typed reference resolve to a missing JS property), so backend-built view XML may not be returned even though the roundtrip succeeds

Credits

• abaplint, open-abap, express-icf-shim, webpacking by larshp