build(sdkjs): fix webpack migration bundle bloat, CI, and coverage gaps

.docker/sdkjs.bake.Dockerfile

@@ -13,10 +13,10 @@ ARG BUILD_ROOT
 #### BASE ####
 FROM ubuntu:24.04 AS web-base
     RUN apt-get update && \
-        apt-get install -y ca-certificates curl gnupg openjdk-21-jdk wget zip brotli bzip2 && \
+        apt-get install -y ca-certificates curl gnupg wget zip brotli bzip2 && \
         curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
         apt-get install -y nodejs && \
-        npm install -g @yao-pkg/pkg grunt-cli && \
+        npm install -g @yao-pkg/pkg && \
         rm -rf /var/lib/apt/lists/*
 
 #### SDKJS ####
@@ -26,11 +26,11 @@ FROM web-base AS sdkjs-base
 
     ARG PRODUCT_VERSION
 
-    COPY sdkjs/build/package*.json /app/build/
+    COPY sdkjs/build/package*.json sdkjs/build/npm-shrinkwrap.json /app/build/
 
     RUN --mount=type=cache,target=/root/.npm \
         cd app/build && \
-        npm install
+        npm ci
 
     COPY sdkjs/ /app
     COPY sdkjs-forms/ /sdkjs-forms
@@ -47,11 +47,12 @@ FROM web-base AS sdkjs-base
     COPY --from=core-wasm ${BUILD_ROOT}/libfont/ /app/common/libfont/
 
 FROM sdkjs-base AS sdkjs-desktop
-    ARG TARGETARCH
+    ENV SDK_ADDONS=/sdkjs-forms
+    ENV SDK_PLATFORM=desktop
     RUN cd app/build && \
-        CC_PLATFORM=$(if [ "$TARGETARCH" = "arm64" ]; then echo "java"; else echo "native,java"; fi) grunt --addon=sdkjs-forms --desktop=true
+        npm run build
 
 FROM sdkjs-base AS sdkjs
-    ARG TARGETARCH
+    ENV SDK_ADDONS=/sdkjs-forms
     RUN cd app/build && \
-        CC_PLATFORM=$(if [ "$TARGETARCH" = "arm64" ]; then echo "java"; else echo "native,java"; fi) grunt --addon=sdkjs-forms
+        npm run build

.eslintignore

@@ -0,0 +1,16 @@
+# Build outputs — generated, not source
+deploy/
+develop/
+build/node_modules/
+
+# Vendor / third-party libraries — not our code
+vendor/
+common/zlib/
+common/libfont/
+
+# Generated / compiled PDF engine files (28k+ lines, not hand-written)
+pdf/src/engine/drawingfile_ie.js
+pdf/build/
+
+# Test fixtures that are not JS source
+tests/

.github/workflows/check-build.yml

@@ -2,11 +2,18 @@ name: Check sdkjs
 on:
   push:
     branches:
+      - main
       - fork
       - develop
       - 'release/**'
       - 'hotfix/**'
   pull_request:
+    branches:
+      - main
+      - fork
+      - develop
+      - 'release/**'
+      - 'hotfix/**'
 jobs:
   code-style:
     runs-on: ubuntu-latest
@@ -62,10 +69,17 @@ jobs:
 
       - name: Build develop SDK
         working-directory: sdkjs
+        env:
+          # sdkjs-forms is checked out as a sibling of sdkjs/, so relative to
+          # sdkjs/build/ (where npm --prefix cds to run the script) it's two
+          # levels up. Without this, the forms/oform tests fail with
+          # "AscOForm is not defined" / "CreateTextForm is not a function"
+          # because the addon is checked out but never merged into the build.
+          SDK_ADDONS: ../../sdkjs-forms
         run: |
-          npm install grunt-cli node-qunit-puppeteer
-          npm install --prefix build
-          node node_modules/grunt-cli/bin/grunt --gruntfile build/Gruntfile.js develop --addon=sdkjs-forms
+          npm install node-qunit-puppeteer
+          npm ci --prefix build
+          npm run --prefix build develop
 
       - name: Run unit tests
         working-directory: sdkjs
@@ -102,9 +116,52 @@ jobs:
         with:
           node-version: 20
 
+      - name: Run build-tooling unit tests
+        run: |
+          cd sdkjs
+          npm ci --prefix build
+          npm test --prefix build
+
       - name: Run build sdkjs
         run: |
           cd sdkjs
-          npm install grunt-cli
-          npm install --prefix build
-          node node_modules/grunt-cli/bin/grunt --gruntfile build/Gruntfile.js
+          # npm ci here too (not just in "Run build-tooling unit tests"): this job
+          # runs on a runner where steps share a workspace but a fresh checkout
+          # may still land without node_modules installed. npm ci is fast on a
+          # warm cache, so this is cheap insurance against "webpack: not found".
+          npm ci --prefix build
+          npm run --prefix build build
+
+      - name: Install QUnit runner dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libatk1.0-0 libcups2 libatk-bridge2.0-0 libdrm2 libxkbcommon0 libxcomposite1 libxdamage1 libxfixes3 libxrandr2 libnss3 libgbm1 libasound2t64
+          cd sdkjs
+          npm install node-qunit-puppeteer
+
+      # The "unit-tests" job above runs the QUnit suite against raw source files
+      # (COMPILED unset) — it never touches the webpack output, so a regression in the
+      # actual bundle (wrong concatenation order, a helper-dedup bug, a stripped-directive
+      # bug, etc.) can pass CI entirely undetected. Re-point develop/sdkjs/*/scripts.js at
+      # the just-built sdk-all-min.js (COMPILED=1) and run a smoke test against that, so
+      # the built artifact itself is exercised at least once.
+      #
+      # tests/common/api/api.js only exercises AscCommon.* (editor-agnostic bootstrap
+      # APIs), never AscWord/AscCommonExcel/etc., so it's safe to reuse verbatim per
+      # module — api-cell.html/api-slide.html/api-visio.html point the same test file
+      # at cell/slide/visio's own scripts.js. This is deliberately NOT extended to
+      # suites touching module-specific APIs (tests/word/api, tests/*/shortcuts,
+      # tests/cell/js-api, ...): COMPILED=1's generated scripts.js references ONLY
+      # sdk-all-min.js, never sdk-all.js (mirrors the original Gruntfile's
+      # writeScripts() exactly — not a webpack-migration change), and
+      # AscWord/AscCommonExcel/etc. live in sdk-all.js, so those suites fail under
+      # COMPILED=1 with "AscWord is not defined" — a pre-existing limitation of
+      # developer-compiled mode, not something this step should be asserting on.
+      - name: Run QUnit against the built bundle (COMPILED=1)
+        run: |
+          cd sdkjs
+          COMPILED=1 npm run --prefix build develop
+          node node_modules/node-qunit-puppeteer/cli.js tests/common/api/api.html 30000 "--no-sandbox"
+          node node_modules/node-qunit-puppeteer/cli.js tests/common/api/api-cell.html 30000 "--no-sandbox"
+          node node_modules/node-qunit-puppeteer/cli.js tests/common/api/api-slide.html 30000 "--no-sandbox"
+          node node_modules/node-qunit-puppeteer/cli.js tests/common/api/api-visio.html 30000 "--no-sandbox"

.gitignore

@@ -1,5 +1,6 @@
 .idea/
 build/node_modules
+build/.webpack-cache
 build/deserializer/cache
 build/$weak$.js
 build/maps

AGENTS.md

@@ -26,7 +26,7 @@ bundles (`sdk-all.js` / `sdk-all-min.js`) that the sibling **web-apps** repo loa
 | `slide/`    | Presentation editor + themes/textures. |
 | `pdf/`      | PDF editor; `src/` is the implementation, `build/` a compiled wrapper, `test/` a harness. |
 | `visio/`    | Diagram editor with its own VSDX serialization (`model/`). |
-| `build/`    | Grunt build: `Gruntfile.js`, `package.json`, `license.header`. Run grunt from **here**. |
+| `build/`    | Webpack build: `webpack.*.mjs`, `scripts/`, `package.json`, `license.header`. Run npm from **here**. See `build/DEVELOPER-GUIDE.md` for the full workflow. |
 | `configs/`  | `<editor>.json` file-lists that drive the build (load order); `externs.json` for Closure. |
 | `tests/`    | QUnit suites per editor + `code-style/check.py` (the lint gate). |
 | `vendor/`   | Third-party libs (jQuery, XRegExp, etc.). Excluded from lint/build minification. |
@@ -36,34 +36,38 @@ bundles (`sdk-all.js` / `sdk-all-min.js`) that the sibling **web-apps** repo loa
 
 For Docker dev environment setup (running the full server stack), see [/DocumentServer/AGENTS.md](../DocumentServer/AGENTS.md).
 
-Requires **Node.js** and, for the full compile, **Java** (the build uses Google Closure
-Compiler, pinned to `google-closure-compiler@20240317`). There is **no root `package.json`**;
-all build deps live in `build/`.
+Requires **Node.js** only — the build now runs on Webpack + Terser (no Java, no Google
+Closure Compiler). There is **no root `package.json`**; all build deps live in `build/`.
+See `build/DEVELOPER-GUIDE.md` for the full workflow (watch mode, source maps, cache).
 
 ```bash
-# Full SDK build (release; ADVANCED minification). Run from build/.
-cd build && npm install -g grunt-cli && npm ci && grunt
+# Full SDK build (release; all 4 modules in parallel, ~50s cold / ~2-3s warm). Run from build/.
+cd build && npm ci && npm run build
 # Outputs: ../deploy/sdkjs/{word,cell,slide,visio}/sdk-all-min.js + sdk-all.js
 ```
 
 ```bash
-# Debug/dev loop — NO recompile, NO Java needed. Run from build/.
-grunt develop              # writes ../develop/sdkjs/<editor>/scripts.js listing the
-                           # individual source files, so editors/tests load unminified sources
-grunt develop --compiled   # same manifest, but pointing at the compiled bundles
+# Debug/dev loop — no bundling. Run from build/.
+npm run develop              # writes ../develop/sdkjs/<editor>/scripts.js listing the
+                              # individual source files, so editors/tests load unminified sources
+COMPILED=1 npm run develop   # same manifest, but pointing at the compiled bundles
 ```
 
-Day-to-day inner loop: edit a source file → `grunt develop` → reload the editor/test page.
-You only need the full `grunt` (Closure) build to produce release/min bundles.
+Day-to-day inner loop: edit a source file → `npm run develop` → reload the editor/test page.
+You only need the full `npm run build` (webpack) to produce release/min bundles, or
+`npm run watch:word` (etc.) for an auto-rebuilding dev bundle.
 
-Other flags: `--desktop=true` (desktop-only files), `--mobile=true`, `--map` (source maps),
-`--level=WHITESPACE_ONLY` (faster, readable output), `--addon=sdkjs-forms` (merges an external
-addon repo's `configs/`).
+Config is via **environment variables**, not CLI flags: `SDK_PLATFORM=desktop` or `mobile`
+(desktop/mobile-only files), `SDK_SOURCE_MAPS=1` (source maps on a production build),
+`SDK_ADDONS=../../sdkjs-forms` (`path.delimiter`-separated list; merges external addon repos'
+`configs/`), `NODE_ENV=development` (readable, unminified output). There is no `--level` /
+`ADVANCED` vs `WHITESPACE_ONLY` distinction anymore — minification is always Terser with
+`mangle: false` (see Gotchas below).
 
 **`make` is NOT the SDK build.** The Makefile's default target also builds the sibling
 `../web-apps` repo and requires it to be checked out next to sdkjs; it is the integration
-build. Use `grunt` in `build/` for SDK-only work. (The Makefile's `SDKJS_FILES` is also stale —
-it lists only `word/sdk-all.js` though grunt builds all editors.)
+build. Use `npm run build` in `build/` for SDK-only work. (The Makefile's `SDKJS_FILES` is also
+stale — it lists only `word/sdk-all.js` though the build produces all editors.)
 
 ### Adding a source file
 
@@ -81,9 +85,9 @@ QUnit suites run headless via `node-qunit-puppeteer`, **from the repo root**:
 
 ```bash
 # one-time setup (from repo root)
-npm install grunt-cli node-qunit-puppeteer
-npm install --prefix build
-node node_modules/grunt-cli/bin/grunt --gruntfile build/Gruntfile.js develop
+npm install node-qunit-puppeteer
+npm ci --prefix build
+npm run --prefix build develop
 
 # run a single suite
 node node_modules/node-qunit-puppeteer/cli.js tests/word/api/api.html 30000 "--no-sandbox"
@@ -98,7 +102,7 @@ CI-guarded by this workflow.
 
 Heaviest coverage is in `tests/cell/spreadsheet-calculation/` (formula engine) and
 `tests/word/`. Suites depend on the generated `develop/sdkjs/*/scripts.js`, so run
-`grunt develop` first.
+`npm run develop` (in `build/`) first.
 
 ## Code style — the build-breakers
 
@@ -192,11 +196,15 @@ Each editor dir has the same set of API files:
 
 - The editor instance lives in both `Asc.editor` and `window.editor` (desktop compat) — code
   often checks both.
-- External callers must use bracket access (`window['Asc']['asc_docs_api']`); dot access on
-  public names gets mangled by Closure ADVANCED minification.
-- `make` pulls in `../web-apps`; for SDK-only work use `grunt` in `build/`.
+- External callers must use bracket access (`window['Asc']['asc_docs_api']`); public names are
+  still published both ways (`window['Name'].Sym = window.Name.Sym = Sym`) as a defensive
+  convention, but the current webpack build runs Terser with `mangle: false` — property/name
+  mangling is not actually applied. Keep using bracket access anyway; don't rely on this as
+  license to switch to dot-access-only code.
+- `make` pulls in `../web-apps`; for SDK-only work use `npm run build` in `build/`.
 - Use `npm ci` (not `npm install`) in `build/` to respect the committed `npm-shrinkwrap.json`.
-- The full `grunt` build needs Java; `grunt develop` does not.
+- No Java/Closure Compiler dependency anymore — `npm run build` and `npm run develop` both only
+  need Node.js.
 
 ## Where future findings live
 

Makefile

@@ -1,5 +1,6 @@
 GRUNT = grunt
-GRUNT_FLAGS = --no-color -v 
+GRUNT_FLAGS = --no-color -v
+SDK_PLATFORM ?=
 
 OUTPUT_DIR = deploy
 OUTPUT = $(OUTPUT_DIR)
@@ -24,6 +25,17 @@ GRUNT_ENV += BUILD_NUMBER=$(BUILD_NUMBER)
 GRUNT_ENV += APP_COPYRIGHT="$(APP_COPYRIGHT)"
 GRUNT_ENV += PUBLISHER_URL="$(PUBLISHER_URL)"
 
+# sdkjs's own build/ was migrated from Grunt to webpack (web-apps' build below is
+# unaffected — it still uses Grunt). The new pipeline reads the same
+# PRODUCT_VERSION/BUILD_NUMBER/APP_COPYRIGHT/PUBLISHER_URL via env vars, plus
+# SDK_PLATFORM instead of a --desktop=true CLI flag, and it errors out on any
+# stray CLI argument — so it must be invoked with no flags at all (no GRUNT_FLAGS).
+# Recursive (=), not simple (:=): SDK_PLATFORM must expand at recipe-run time so
+# the `desktop:` target-specific override below is picked up, not the empty
+# top-level default in effect at parse time.
+SDKJS_ENV = $(GRUNT_ENV)
+SDKJS_ENV += SDK_PLATFORM=$(SDK_PLATFORM)
+
 WEBAPPS_DIR := web-apps
 
 WEBAPPS = $(OUTPUT)/$(WEBAPPS_DIR)
@@ -49,9 +61,10 @@ $(WEBAPPS_FILES): $(NODE_MODULES) $(SDKJS_FILES)
 
 $(SDKJS_FILES): $(NODE_MODULES)
 	cd build && \
-		$(GRUNT_ENV) $(GRUNT) $(GRUNT_FLAGS)
+		$(SDKJS_ENV) npm run build
 
 desktop: GRUNT_FLAGS += --desktop=true
+desktop: SDK_PLATFORM = desktop
 desktop: all
 
 clean: