diff --git a/.github/workflows/accept-baselines-fix-lints.yaml b/.github/workflows/accept-baselines-fix-lints.yaml
index d92b1ae1836fd..5c1ef6d21f07b 100644
--- a/.github/workflows/accept-baselines-fix-lints.yaml
+++ b/.github/workflows/accept-baselines-fix-lints.yaml
@@ -10,10 +10,11 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Use node version 12
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12
         registry-url: https://registry.npmjs.org/
+        cache: npm
 
     - name: Configure Git, Run Tests, Update Baselines, Apply Fixes
       run: |
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index df96f73376b56..b6e28183f379d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,9 +23,10 @@ jobs:
       with:
         fetch-depth: 5
     - name: Use node version ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: ${{ matrix.node-version }}
+        cache: npm
     - name: Remove existing TypeScript
       run: |
         npm uninstall typescript --no-save
diff --git a/.github/workflows/new-release-branch.yaml b/.github/workflows/new-release-branch.yaml
index 6c07e96bbbbc9..8a92bc238a32b 100644
--- a/.github/workflows/new-release-branch.yaml
+++ b/.github/workflows/new-release-branch.yaml
@@ -10,9 +10,10 @@ jobs:
 
     steps:
     - name: Use node version 12.x
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12.x
+        cache: npm
     - uses: actions/checkout@v2
       with:
         fetch-depth: 5
diff --git a/.github/workflows/nightly.yaml b/.github/workflows/nightly.yaml
index abe704bb564d8..184c2e0e8fed2 100644
--- a/.github/workflows/nightly.yaml
+++ b/.github/workflows/nightly.yaml
@@ -15,10 +15,11 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Use node version 12
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12
         registry-url: https://registry.npmjs.org/
+        cache: npm
     - name: Setup and publish nightly
       run: |
         npm whoami
diff --git a/.github/workflows/release-branch-artifact.yaml b/.github/workflows/release-branch-artifact.yaml
index 363d03fc2f69b..d662297f63d44 100644
--- a/.github/workflows/release-branch-artifact.yaml
+++ b/.github/workflows/release-branch-artifact.yaml
@@ -12,9 +12,10 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Use node version 12
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12
+        cache: npm
     - name: Remove existing TypeScript
       run: |
         npm uninstall typescript --no-save
diff --git a/.github/workflows/set-version.yaml b/.github/workflows/set-version.yaml
index d5bd8faa83438..3b07869bfebaf 100644
--- a/.github/workflows/set-version.yaml
+++ b/.github/workflows/set-version.yaml
@@ -10,9 +10,10 @@ jobs:
 
     steps:
     - name: Use node version 12.x
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12.x
+        cache: npm
     - uses: actions/checkout@v2
       with:
         ref: ${{ github.event.client_payload.branch_name }}
diff --git a/.github/workflows/sync-branch.yaml b/.github/workflows/sync-branch.yaml
index e3f67be09fed5..d42a2970a2162 100644
--- a/.github/workflows/sync-branch.yaml
+++ b/.github/workflows/sync-branch.yaml
@@ -15,9 +15,10 @@ jobs:
 
     steps:
     - name: Use node version 12.x
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12.x
+        cache: npm
     - uses: actions/checkout@v2
       with:
         ref: ${{ github.event.inputs.branch_name || github.event.client_payload.branch_name }}
diff --git a/.github/workflows/twoslash-repros.yaml b/.github/workflows/twoslash-repros.yaml
index f4888f5334163..36b910af8abad 100644
--- a/.github/workflows/twoslash-repros.yaml
+++ b/.github/workflows/twoslash-repros.yaml
@@ -14,7 +14,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Use node
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
+      with:
+        cache: npm
     - run: |
        npm init -y
        npm install --save typescript@next
diff --git a/.github/workflows/update-lkg.yml b/.github/workflows/update-lkg.yml
index cf81cc97db9fb..fbb7831c3c6da 100644
--- a/.github/workflows/update-lkg.yml
+++ b/.github/workflows/update-lkg.yml
@@ -10,10 +10,11 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Use node version 12
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: 12
         registry-url: https://registry.npmjs.org/
+        cache: npm
 
     - name: Configure Git and Update LKG
       run: |
diff --git a/.github/workflows/update-package-lock.yaml b/.github/workflows/update-package-lock.yaml
index 0e4d1509333e3..2a7b2ece9d547 100644
--- a/.github/workflows/update-package-lock.yaml
+++ b/.github/workflows/update-package-lock.yaml
@@ -13,10 +13,11 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - uses: actions/setup-node@v1
+    - uses: actions/setup-node@v2
       with:
         node-version: 12
         registry-url: https://registry.npmjs.org/
+        cache: npm
 
     - name: Configure git and update package-lock.json
       run: |
diff --git a/src/testRunner/parallel/worker.ts b/src/testRunner/parallel/worker.ts
index 21570ab3e1e62..8623f6e879bf6 100644
--- a/src/testRunner/parallel/worker.ts
+++ b/src/testRunner/parallel/worker.ts
@@ -209,7 +209,12 @@ namespace Harness.Parallel.Worker {
             const errors: ErrorInfo[] = [];
             const passes: TestInfo[] = [];
             const start = +new Date();
-            const runner = new Mocha.Runner(suite, /*delay*/ false);
+            /* DeprecationWarning: "Runner(suite: Suite, delay: boolean)" is deprecated. Use "Runner(suite: Suite, {delay: boolean})" instead.*/
+            const runner = new Mocha.Runner(
+                suite,
+                // TODO: Remove `as any as boolean` when @types/mocha is version 9.x
+                { delay: false } as any as boolean /* Because Mocha is out of sync with is definition  9.0.2/8.2 */ 
+            );
 
             runner
                 .on("start", () => {