ci: build binaries on multi-platforms

hdiutil was removed because it uses old APIs, and fails to build. there
is no reference in the commit in which it was added to package.json.
it looks to me that hdiutil is not maintained.

update electron-builder. version 14.5.x is too old and has bugs on macos
and Windows. at least, 21.2.x is required to build the code.
see electron-userland/electron-builder#3990
for example.

for ARCH, `amd64` and `i386` are chosen because they are widely used,
and what `uname -m` returns. i'm open for alternatives.

there are too many `if: matrix.OS == 'windows'`. just to absorb path
separator difference. when Windows Subsystem for Linux, or WSL, is
available on hosted GitHub Actions runners, they can be removed. maybe,
MSYS2 has solutions, but i did not go father because i need a working
workflow first. see available software at:
https://github.com/actions/virtual-environments/blob/master/images/win/Windows2019-Readme.md

.github/workflows/release.yml

@@ -0,0 +1,175 @@
+---
+name: Release CI
+on:
+  - push
+  - pull_request
+
+jobs:
+  build:
+    runs-on: ${{ matrix.RUNNER_PLATFORM }}
+    strategy:
+      matrix:
+        version:
+          - linux-amd64
+          - macos-amd64
+          - windows-amd64
+            # XXX probably, 32 bit Windows is not so common, but built it
+            # anyway to see if the workflow has portability issues.
+          - windows-i386
+        include:
+          - version: linux-amd64
+            OS: linux
+            ARCH: amd64
+            RUNNER_PLATFORM: ubuntu-latest
+            ELECTRON_BUILDER_FLAGS: --linux
+            # XXX ldd /root/.cache/electron-builder/AppImage/AppImage-09-07-16-linux/xorriso
+            # libreadline.so.6 => not found
+            BUILD_DEPEND: graphicsmagick xz-utils xorriso
+            BUILD_ENVIRONMENT_VAR: USE_SYSTEM_XORRISO=true
+            BUILD_ARTIFACT_FILE_EXT: AppImage
+            PKG_INSTALL_CMD: sudo apt-get install
+          - version: macos-amd64
+            OS: macos
+            ARCH: amd64
+            RUNNER_PLATFORM: macos-latest
+            ELECTRON_BUILDER_FLAGS: --macos
+            BUILD_DEPEND: ${{ false }}
+            BUILD_ENVIRONMENT_VAR: ""
+            BUILD_ARTIFACT_FILE_EXT: dmg
+            PKG_INSTALL_CMD: brew install
+          - version: windows-i386
+            OS: windows
+            ARCH: i386
+            RUNNER_PLATFORM: windows-latest
+            ELECTRON_BUILDER_FLAGS: --ia32
+            BUILD_DEPEND: ${{ false }}
+            BUILD_ENVIRONMENT_VAR: ""
+            BUILD_ARTIFACT_FILE_EXT: exe
+            PKG_INSTALL_CMD: ""
+          - version: windows-amd64
+            OS: windows
+            ARCH: amd64
+            RUNNER_PLATFORM: windows-latest
+            ELECTRON_BUILDER_FLAGS: --x64
+            BUILD_DEPEND: ${{ false }}
+            BUILD_ENVIRONMENT_VAR: ""
+            BUILD_ARTIFACT_FILE_EXT: exe
+            PKG_INSTALL_CMD: ""
+        node-version:
+          - 10.x
+    steps:
+      - name: Install required packages
+        if: matrix.BUILD_DEPEND
+        run: ${{ matrix.PKG_INSTALL_CMD }} ${{ matrix.BUILD_DEPEND }}
+
+      - name: Checkout lw.comm-server
+        uses: actions/checkout@v2
+        with:
+          path: lw.comm-server
+
+      - name: Checkout LaserWeb4
+        uses: actions/checkout@v2
+        with:
+          repository: trombik/LaserWeb4
+          path: LaserWeb4
+          ref: sync-package-json
+          # keep all history. other step needs commit logs.
+          fetch-depth: 0
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Get npm cache directory
+        id: npm-cache
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+
+      - name: Cache npm
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.npm-cache.outputs.dir }}
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+
+      - name: Build LaserWeb4 (Unix)
+        if: matrix.OS != 'windows'
+        run: |
+          cd ${GITHUB_WORKSPACE}/LaserWeb4
+          npm ci
+          npm run installdev
+          npm run bundle-dev
+
+      - name: Build LaserWeb4 (Windows)
+        if: matrix.OS == 'windows'
+        shell: cmd
+        run: |
+          cd %GITHUB_WORKSPACE%\LaserWeb4
+          npm ci
+          npm run installdev
+          npm run bundle-dev
+
+      - name: Run npm ci in lw.comm-server (Unix)
+        if: matrix.OS != 'windows'
+        run: |
+          cd ${GITHUB_WORKSPACE}/lw.comm-server
+          npm ci
+
+      - name: Run npm ci in lw.comm-server (Windows)
+        if: matrix.OS == 'windows'
+        shell: cmd
+        run: |
+          cd %GITHUB_WORKSPACE%\lw.comm-server
+          npm ci
+
+      - name: Rebuild electron (Unix)
+        if: matrix.OS != 'windows'
+        run: |
+          cd ${GITHUB_WORKSPACE}/lw.comm-server
+          ./node_modules/.bin/electron-rebuild
+
+      - name: Rebuild electron (Windows)
+        if: matrix.OS == 'windows'
+        shell: cmd
+        run: |
+          cd %GITHUB_WORKSPACE%\lw.comm-server
+          .\node_modules\.bin\electron-rebuild
+
+      - name: Build (Unix)
+        if: matrix.OS != 'windows'
+        run: |
+          cd ${GITHUB_WORKSPACE}/LaserWeb4
+          UI_VERSION=$(git describe --abbrev=0 --tags | tr -d 'v')
+
+          cd ${GITHUB_WORKSPACE}/lw.comm-server
+          SERVER_VERSION=$(cat version.txt | cut -c 3-6)
+          env ${{ matrix.BUILD_ENVIRONMENT_VAR }} \
+          ./node_modules/.bin/electron-builder build --config.buildVersion=$UI_VERSION -p never ${{ matrix.ELECTRON_BUILDER_FLAGS }}
+
+      - name: Build (Windows)
+        if: matrix.OS == 'windows'
+        shell: bash
+        run: |
+          cd ${GITHUB_WORKSPACE}\\LaserWeb4
+          UI_VERSION=$(git describe --abbrev=0 --tags | tr -d 'v')
+
+          cd ${GITHUB_WORKSPACE}\\lw.comm-server
+          SERVER_VERSION=$(cat version.txt | cut -c 3-6)
+          env ${{ matrix.BUILD_ENVIRONMENT_VAR }} \
+          node_modules\\.bin\\electron-builder build --config.buildVersion=$UI_VERSION -p never ${{ matrix.ELECTRON_BUILDER_FLAGS }}
+
+      - name: Upload build artifact (Unix)
+        if: matrix.OS != 'windows'
+        uses: actions/upload-artifact@v2
+        with:
+          name: LaserWeb-${{ matrix.OS }}-${{ matrix.ARCH }}-${{ github.sha }}
+          path: ${{ github.workspace }}/lw.comm-server/dist/*.${{ matrix.BUILD_ARTIFACT_FILE_EXT }}
+
+      - name: Upload build artifact (Windows)
+        if: matrix.OS == 'windows'
+        uses: actions/upload-artifact@v2
+        with:
+          name: LaserWeb-${{ matrix.OS }}-${{ matrix.ARCH }}-${{ github.sha }}
+          path: ${{ github.workspace }}\lw.comm-server\dist\*.${{ matrix.BUILD_ARTIFACT_FILE_EXT }}