Switched unit test runner from jest to vitest.

Fixed tests that regressed after the change.
A few tests are now marked as skipped. In the future, these should be replaced with e2e tests, or we should investigate how to fix them.

.github/workflows/node.js.yml

@@ -30,6 +30,30 @@ jobs:
     - run: npm ci
     - run: npm run lint
 
+  unit-tests:
+    # Lint is fast. If we wait for it we guarantee a cache hit on dependencies.
+    needs: lint
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [16.x]
+        # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v2
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'npm'
+
+    - run: npm ci
+    - run: npm run build
+    - run: npm run test:unit
+
   component-tests:
     # Lint is fast. If we wait for it we guarantee a cache hit on dependencies.
     needs: lint
@@ -52,7 +76,7 @@ jobs:
 
     - run: npm ci
     - run: npm run build
-    - run: npm run component
+    - run: npm run test:component
 
   e2e-tests:
     # Lint is fast. If we wait for it we guarantee a cache hit on dependencies.