ci: Run unit tests per workspace in parallel

Rework the test workflow to use a dynamic matrix that discovers all
workspaces with a unit script automatically. Each workspace runs as
its own job, making failures immediately visible per package in the
GitHub Actions UI. A single gate job (CI) aggregates the results for
use as the required status check in branch protection.

Author: RandomByte

.github/workflows/test.yml

@@ -12,13 +12,50 @@ permissions:
   contents: read
 
 jobs:
-  test:
-    name: Unit and Integration
+  discover:
+    name: Discover workspaces
+    runs-on: ubuntu-24.04
+    outputs:
+      workspaces: ${{ steps.find.outputs.workspaces }}
+    steps:
+
+    - uses: actions/checkout@v6
+
+    - name: Find workspaces with unit tests
+      id: find
+      run: |
+        workspaces=$(node -e "
+          const {readFileSync, readdirSync, existsSync} = require('fs');
+          const {join} = require('path');
+          const root = JSON.parse(readFileSync('package.json', 'utf8'));
+          const dirs = root.workspaces.flatMap(pattern => {
+            const base = pattern.replace('/*', '');
+            if (!existsSync(base)) return [];
+            return readdirSync(base, {withFileTypes: true})
+              .filter(d => d.isDirectory())
+              .map(d => join(base, d.name));
+          });
+          const names = dirs
+            .filter(d => {
+              const p = join(d, 'package.json');
+              if (!existsSync(p)) return false;
+              const pkg = JSON.parse(readFileSync(p, 'utf8'));
+              return Boolean(pkg.scripts && pkg.scripts.unit);
+            })
+            .map(d => JSON.parse(readFileSync(join(d, 'package.json'), 'utf8')).name);
+          console.log(JSON.stringify(names));
+        ")
+        echo "workspaces=$workspaces" >> "$GITHUB_OUTPUT"
+
+  unit:
+    name: "${{ matrix.workspace }} (Node ${{ matrix.version }}, ${{ matrix.os }})"
+    needs: discover
     strategy:
-      fail-fast: false # Do not stop other jobs if one fails
+      fail-fast: false
       matrix:
         version: [22, 24]
         os: [ubuntu-24.04, windows-2025, macos-15]
+        workspace: ${{ fromJSON(needs.discover.outputs.workspaces) }}
     runs-on: ${{ matrix.os }}
     steps:
 
@@ -38,4 +75,13 @@ jobs:
       run: npm ci
 
     - name: Run unit tests
-      run: npm run unit
+      run: npm run unit --workspace=${{ matrix.workspace }}
+
+  ci:
+    name: CI
+    needs: [unit]
+    if: always()
+    runs-on: ubuntu-24.04
+    steps:
+    - run: exit 1
+      if: contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled')