chore: Use Yarn v4

Author: akash1810

.github/workflows/cdk-test.yml

@@ -27,8 +27,10 @@ jobs:
           cache: "yarn"
           cache-dependency-path: cdk/yarn.lock
 
+      - run: corepack enable
+
       - name: Install
-        run: yarn install --frozen-lockfile
+        run: yarn install --immutable
 
       - name: Test
         run: yarn test

.github/workflows/notification-worker-lambdas.yml

@@ -34,8 +34,8 @@ jobs:
 
       - uses: actions/setup-node@v6
         with:
-          cache: npm
-          cache-dependency-path: cdk/package-lock.json
+          cache: yarn
+          cache-dependency-path: cdk/yarn.lock
           node-version-file: .nvmrc
 
       - uses: aws-actions/configure-aws-credentials@v2
@@ -74,20 +74,22 @@ jobs:
           NOTIFICATION_LAMBDA_REPOSITORY_URL: ${{ secrets.NOTIFICATION_LAMBDA_REPOSITORY_URL }}
           BUILD_NUMBER: ${{ github.run_number }}
 
+      - run: corepack enable
+
       - name: CDK synth (worker lambda cdk directory)
         working-directory: cdk
         run: |
-          yarn install
+          yarn install --immutable
           yarn test
           yarn synth
 
       - name: CDK synth (root cdk directory)
         working-directory: cdk
         run: |
-          npm install
-          npm run lint
-          npm test
-          npm run synth
+          yarn install --immutable
+          yarn lint
+          yarn test
+          yarn synth
 
       - name: Upload to riff-raff
         uses: guardian/actions-riff-raff@v4

.github/workflows/registration.yml

@@ -35,17 +35,19 @@ jobs:
 
       - uses: actions/setup-node@v6
         with:
-          cache: npm
-          cache-dependency-path: cdk/package-lock.json
+          cache: yarn
+          cache-dependency-path: cdk/yarn.lock
           node-version-file: .nvmrc
 
+      - run: corepack enable
+
       - name: CDK synth
         run: |
           cd cdk
-          npm install
-          npm run lint
-          npm test
-          npm run synth
+          yarn install --immutable
+          yarn lint
+          yarn test
+          yarn synth
 
       - name: Compile, test and package
         run: sbt "project common" "compile" "test" "project registration" "compile" "test" "debian:packageBin"

.github/workflows/slo-monitor.yml

@@ -33,8 +33,8 @@ jobs:
 
       - uses: actions/setup-node@v6
         with:
-          cache: npm
-          cache-dependency-path: cdk/package-lock.json
+          cache: yarn
+          cache-dependency-path: cdk/yarn.lock
           node-version-file: .nvmrc
 
       - name: Compile, test and assembly
@@ -53,13 +53,15 @@ jobs:
       - name: Copy jar to root
         run: cp slomonitor/target/scala-*/slomonitor.jar .
 
+      - run: corepack enable
+
       - name: CDK synth
         run: |
           cd cdk
-          npm install
-          npm run lint
-          npm test
-          npm run synth
+          yarn install --immutable
+          yarn lint
+          yarn test
+          yarn synth
 
       - name: Upload to riff-raff
         uses: guardian/actions-riff-raff@v4

cdk/.yarn/install-state.gz

@@ -0,0 +1 @@
+nodeLinker: node-modules

cdk/.yarnrc.yml

@@ -17,9 +17,9 @@ these with almost identical configurations.
 
 ### Useful commands
 
-* `npm run build`   compile typescript to js
-* `npm run watch`   watch for changes and compile
-* `npm run test`    perform the jest unit tests
+* `yarn build`   compile typescript to js
+* `yarn watch`   watch for changes and compile
+* `yarn test`    perform the jest unit tests
 * `cdk deploy`      deploy this stack to your default AWS account/region
 * `cdk diff`        compare deployed stack with current state
 * `cdk synth`       emits the synthesized CloudFormation template

cdk/README.md

@@ -67,5 +67,6 @@
       ".eslintrc.js",
       "jest.config.js"
     ]
-  }
+  },
+  "packageManager": "yarn@4.12.0"
 }