Added new gh check for warnings

Author: vsubhuman

.github/workflows/pr-checks.yml

@@ -41,3 +41,30 @@ jobs:
       - name: rust:build-browser
         run: |
           npm run rust:build-browser
+  check-warns:
+    if: github.event.review && (github.event.review.state == 'approved' || contains(github.event.review.body, '/check'))
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+      - uses: actions/setup-node@v1
+        with:
+          node-version: '12.18.1'
+      - name: Cache node modules
+        uses: actions/cache@v1
+        with:
+          path: ~/.npm # npm cache files are stored in `~/.npm` on Linux/macOS
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-build-${{ env.cache-name }}-
+            ${{ runner.os }}-build-
+            ${{ runner.os }}-
+      - name: prepare-rust
+        run: |
+          rustup install stable
+          rustup target add wasm32-unknown-unknown --toolchain stable
+          curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+      - name: rust:check-warnings
+        run: |
+          npm run rust:check-warnings

package.json

@@ -9,6 +9,7 @@
     "rust:build-asm": "(rimraf ./rust/pkg && cd rust; wasm-pack build --target=browser; wasm-pack pack) && npm run asm:build && npm run js:flowgen",
     "rust:publish": "cd rust && cargo publish && cd ../",
     "asm:build": "./binaryen/bin/wasm2js ./rust/pkg/cardano_serialization_lib_bg.wasm --output ./rust/pkg/cardano_serialization_lib.asm.js && node ./scripts/wasm-to-asm",
+    "rust:check-warnings": "(cd rust; RUSTFLAGS=\"-D warnings\" cargo build)",
     "rust:test": "(cd rust; cargo test)",
     "js:flowgen": "flowgen ./rust/pkg/cardano_serialization_lib.d.ts -o ./rust/pkg/cardano_serialization_lib.js.flow --add-flow-header",
     "js:prepublish": "npm run rust:test && rimraf ./publish && cp -r ./rust/pkg ./publish && cp README.md publish/ && cp LICENSE publish/",