Add GH actions

Author: alex35mil

.github/workflows/pr.yml

@@ -0,0 +1,43 @@
+name: build
+
+on:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: Build on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        node-version: [16.x]
+        os: [ubuntu-latest, macOS-latest, windows-latest]
+
+    steps:
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+
+      - name: Restore yarn cache
+        id: yarn-cache
+        uses: actions/cache@v1
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ matrix.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ matrix.os }}-yarn-
+
+      - name: Install deps
+        run: yarn install
+
+      - name: Build lib
+        run: yarn rescript build -with-deps