Speedup / make more reliable NodeJS + ElectronJS builds

[lissyx]

NodeJS / ElectronJS builds can be slower because of:

• node_modules dependencies to fetch
• nodejs / electronjs headers to download
• both those also make it more sensible to infra issues

It would be nice to leverage caching capabilities of GitHub Actions to help with that

• caching the nodejs/electronjs headers: --devdir parameter in

  DeepSpeech/.github/actions/node-build/action.yml

  Line 42 in 0ce835a

                 NODE_DEVDIR=--devdir=tmp/headers/nodejs/${node} \ 

• caching the node_modules from build time:

  DeepSpeech/.github/workflows/macOS-amd64.yml

  Lines 301 to 343 in 0ce835a

     build-nodejs-macOS: 
       name: "Build NodeJS and ElectronJS for macOS" 
       runs-on: macos-10.15 
       needs: [ build-lib_macOS, swig_macOS ] 
       strategy: 
         matrix: 
           build-flavor: ["tf", "tflite"] 
       steps: 
         - uses: actions/checkout@v2 
           with: 
             fetch-depth: 1 
         - uses: actions/download-artifact@v2 
           with: 
             name: "native_client.${{ matrix.build-flavor }}.tar.xz" 
             path: ${{ github.workspace }}/tensorflow/bazel-bin/native_client/ 
         - run: | 
             cd ${{ github.workspace }}/tensorflow/bazel-bin/native_client/ 
             tar xf native_client.tar.xz 
             ls -hal 
             cd ${{ github.workspace }}/ 
         - uses: actions/download-artifact@v2 
           with: 
             name: "swig_macOS" 
             path: ${{ github.workspace }}/native_client/ds-swig/ 
         - run: | 
             ls -hal ${{ github.workspace }}/native_client/ds-swig/bin 
             ln -s ds-swig ${{ github.workspace }}/native_client/ds-swig/bin/swig 
             chmod +x ${{ github.workspace }}/native_client/ds-swig/bin/ds-swig ${{ github.workspace }}/native_client/ds-swig/bin/swig 
         - uses: actions/setup-node@v2 
           with: 
             node-version: 12 
         - uses: ./.github/actions/node-build 
           with: 
             nodejs_versions: "10.0.0 11.0.0 12.7.0 13.0.0 14.0.0 15.0.0" 
             electronjs_versions: "5.0.13 6.0.12 6.1.7 7.0.1 7.1.8 8.0.1 9.0.1 9.1.0 9.2.0 10.0.0 10.1.0 11.0.0 12.0.0" 
         - uses: actions/upload-artifact@v2 
           with: 
             name: "nodewrapper-${{ matrix.build-flavor }}.tar.gz" 
             path: ${{ github.workspace }}/native_client/javascript/wrapper.tar.gz 
         - uses: actions/upload-artifact@v2 
           with: 
             name: "deepspeech-${{ matrix.build-flavor }}.tgz" 
             path: ${{ github.workspace }}/native_client/javascript/deepspeech-*.tgz 

• caching the node_modules from test runs:

  DeepSpeech/.github/workflows/macOS-amd64.yml

  Lines 430 to 523 in 0ce835a

     test-nodejs-macOS: 
       name: "Test NodeJS bindings on macOS" 
       runs-on: macos-10.15 
       needs: [ build-nodejs-macOS, train-test-model ] 
       if: ${{ github.event_name == 'pull_request' }} 
       strategy: 
         matrix: 
           # https://nodejs.org/en/about/releases/ 
           nodejs-version: [10, 12, 14, 15] 
           build-flavor: ["tf", "tflite"] 
           models: ["test"] 
           bitrate: ["16k"] 
       env: 
         TASKCLUSTER_TMP_DIR: ${{ github.workspace }}/tmp/ 
         DEEPSPEECH_PROD_MODEL: https://github.com/reuben/DeepSpeech/releases/download/v0.7.0-alpha.3/output_graph.pb 
         DEEPSPEECH_PROD_MODEL_MMAP: https://github.com/reuben/DeepSpeech/releases/download/v0.7.0-alpha.3/output_graph.pbmm 
         DEEPSPEECH_TEST_MODEL: ${{ github.workspace }}/tmp/output_graph.pb 
         EXPECTED_TENSORFLOW_VERSION: "TensorFlow: v2.3.0-6-g23ad988" 
       steps: 
         - uses: actions/checkout@v2 
           with: 
             fetch-depth: 1 
         - uses: actions/setup-node@v2 
           with: 
             node-version: ${{ matrix.nodejs-version }} 
         - uses: actions/download-artifact@v2 
           with: 
             name: "deepspeech-${{ matrix.build-flavor }}.tgz" 
             path: ${{ env.TASKCLUSTER_TMP_DIR }} 
         - uses: actions/download-artifact@v2 
           with: 
             name: "test-model.${{ matrix.build-flavor }}-${{ matrix.bitrate }}.zip" 
             path: ${{ env.TASKCLUSTER_TMP_DIR }} 
           if: matrix.models == 'test' 
         - run: | 
             ls -hal ${{ env.TASKCLUSTER_TMP_DIR }}/ 
           if: matrix.models == 'test' 
         - run: | 
             ls -hal ${{ env.TASKCLUSTER_TMP_DIR }}/ 
             npm install ${{ env.TASKCLUSTER_TMP_DIR }}/deepspeech*.tgz 
         - uses: ./.github/actions/run-tests 
           with: 
             runtime: "node" 
             build-flavor: ${{ matrix.build-flavor }} 
             bitrate: ${{ matrix.bitrate }} 
             model-kind: ${{ matrix.models }} 
     test-electronjs-macOS: 
       name: "Test ElectronJS bindings on macOS" 
       runs-on: macos-10.15 
       needs: [ build-nodejs-macOS, train-test-model ] 
       if: ${{ github.event_name == 'pull_request' }} 
       strategy: 
         matrix: 
           electronjs-version: [5.0.13, 6.1.7, 7.1.8, 8.0.1, 9.2.0, 10.1.0, 11.0.0, 12.0.0] 
           build-flavor: ["tf", "tflite"] 
           models: ["test"] 
           bitrate: ["16k"] 
       env: 
         TASKCLUSTER_TMP_DIR: ${{ github.workspace }}/tmp/ 
         DEEPSPEECH_PROD_MODEL: https://github.com/reuben/DeepSpeech/releases/download/v0.7.0-alpha.3/output_graph.pb 
         DEEPSPEECH_PROD_MODEL_MMAP: https://github.com/reuben/DeepSpeech/releases/download/v0.7.0-alpha.3/output_graph.pbmm 
         DEEPSPEECH_TEST_MODEL: ${{ github.workspace }}/tmp/output_graph.pb 
         EXPECTED_TENSORFLOW_VERSION: "TensorFlow: v2.3.0-6-g23ad988" 
       steps: 
         - uses: actions/checkout@v2 
           with: 
             fetch-depth: 1 
         - uses: actions/setup-node@v2 
           with: 
             node-version: 12 
         - uses: actions/download-artifact@v2 
           with: 
             name: "deepspeech-${{ matrix.build-flavor }}.tgz" 
             path: ${{ env.TASKCLUSTER_TMP_DIR }} 
         - uses: actions/download-artifact@v2 
           with: 
             name: "test-model.${{ matrix.build-flavor }}-${{ matrix.bitrate }}.zip" 
             path: ${{ env.TASKCLUSTER_TMP_DIR }} 
           if: matrix.models == 'test' 
         - run: | 
             ls -hal ${{ env.TASKCLUSTER_TMP_DIR }}/ 
           if: matrix.models == 'test' 
         - run: | 
             ls -hal ${{ env.TASKCLUSTER_TMP_DIR }}/ 
             npm install ${{ env.TASKCLUSTER_TMP_DIR }}/deepspeech*.tgz 
         - run: | 
             npm install electron@${{ matrix.electronjs-version }} 
         - uses: ./.github/actions/run-tests 
           with: 
             runtime: "electronjs" 
             build-flavor: ${{ matrix.build-flavor }} 
             bitrate: ${{ matrix.bitrate }} 
             model-kind: ${{ matrix.models }} 
           timeout-minutes: 5