chore: add coverage merge script

Author: david-luna

.github/workflows/pr-test.yml

@@ -183,17 +183,12 @@ jobs:
         with:
           name: tests-build-cache-${{ github.run_number }}
           path: .nx
-      # TODO: check if compiling only the affected modules is correct
       - name: Compile (Delta)
         run: npm run compile:ci:changed
       - name: Unit tests (Delta)
         run: npm run test:ci:changed
       - name: Test All Versions (Delta)
         run: npm run test-all-versions:ci:changed
-      # TODO: remove
-      - name: List instr files
-        run: find plugins/node/instrumentation-undici
-      # TODO: save coverage for later
       - name: Upload Test Artifacts
         uses: actions/upload-artifact@v4
         with:
@@ -205,7 +200,6 @@ jobs:
             !node_modules
             **/.nyc_output/**
 
-  # TODO: how to put back everythign in coverage???
   test-coverage-report:
     runs-on: ubuntu-latest
     needs: unit-and-tav-test
@@ -219,6 +213,7 @@ jobs:
           node-version: 18
       - name: Install
         run: npm ci
+      # TODO: add the rest of versions (18.19.0 & 20.6.0)? or are these enough??
       - name: Download Test Artifacts (18)
         uses: actions/download-artifact@v4
         with:
@@ -234,9 +229,14 @@ jobs:
         with:
           name: tests-coverage-cache-${{ github.run_number }}-22
           path: .
-      - name: List instr files
-        run: find plugins/node/instrumentation-undici
-      # - name: Report Coverage
+      - name: List instr folders
+        run: ls -la plugins/node/instrumentation-undici
+      - name: Merge coverage
+        run: cd plugins/node/instrumentation-undici && npm run coverage:merge
+      - name: Check coverage
+        run: find plugins/node/instrumentation-undici/coverage
+      
+        # - name: Report Coverage
       #   uses: codecov/codecov-action@v5
       #   env:
       #     CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

plugins/node/instrumentation-undici/package.json

@@ -16,7 +16,8 @@
     "lint": "eslint . --ext .ts",
     "lint:fix": "eslint . --ext .ts --fix",
     "watch": "tsc -w",
-    "version:update": "node ../../../scripts/version-update.js"
+    "version:update": "node ../../../scripts/version-update.js",
+    "coverage:merge": "nyc merge .nyc_output coverage/coverage-final.json"
   },
   "keywords": [
     "opentelemetry",