Restore cache

.github/workflows/tests.yml

@@ -18,6 +18,16 @@ jobs:
           node-version: 16.x
           registry-url: https://registry.npmjs.org
 
+      - id: yarn-cache
+        run: echo "::set-output name=dir::$(yarn cache dir)"
+
+      - uses: actions/cache@v1
+        with:
+          path: ${{ steps.yarn-cache.outputs.dir }}
+          key: yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            yarn-
+
       - name: Install dependencies
         run: yarn install --frozen-lockfile