Add Emscripten testing to CI.

.github/workflows/main.yml

@@ -22,12 +22,19 @@ jobs:
       PLATFORM: ${{ matrix.config.platform }}
       DOTNET_NOLOGO: true
       DOTNET_CLI_TELEMETRY_OPTOUT: true
+      EMSCRIPTEN_VERSION: 3.1.65
 
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: '0'
 
+      - name: Setup emsdk
+        uses: mymindstorm/setup-emsdk@v11
+        with:
+          version: ${{ env.EMSCRIPTEN_VERSION }}
+          actions-cache-folder: emsdk-cache-${{ runner.os }}
+
       - name: Install nbgv
         if: startsWith(matrix.config.os, 'macos')
         run: |
@@ -69,6 +76,11 @@ jobs:
         run: tests/quickjs/test.sh
         if: runner.os != 'Windows'
 
+      - name: Test (Emscripten)
+        shell: bash
+        run: tests/emscripten/test.sh
+        if: runner.os != 'Windows'
+
       - name: Pack
         shell: bash
         run: build/build.sh prepack -platform $PLATFORM