diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
new file mode 100644
index 00000000..76d41f7d
--- /dev/null
+++ b/.github/workflows/build_and_test.yml
@@ -0,0 +1,31 @@
+on:
+  workflow_call:
+    inputs:
+      node-version-for-testing:
+        required: false
+        default: 18.x
+        type: string
+      build-cmd:
+        required: false
+        default: npm run build
+        type: string
+      test-cmd:
+        required: true
+        type: string
+jobs:
+  reusable_workflow_job:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: use node.js v17.x for build
+        uses: actions/setup-node@v1
+        with:
+          node-version: 18.x
+      - run: npm ci --no-optional
+      - run: ${{ inputs.build-cmd }}
+      - name: use node.js for test execution
+        uses: actions/setup-node@v1
+        with:
+          node-version: ${{ inputs.node-version-for-testing }}
+      - run: npm ci --no-optional
+      - run: ${{ inputs.test-cmd }}
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 3342e8bd..e7ee73b8 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -5,19 +5,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: use node.js v15.x
+      - name: use node.js v17.x
         uses: actions/setup-node@v1
         with:
-          node-version: 15.x
+          node-version: 17.x
       - run: npm ci --no-optional
       - run: npm run lint
   lint-unused-code: # look for unused functions and unused exports
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: use node.js v16.x
+      - name: use node.js v17.x
         uses: actions/setup-node@v1
         with:
-          node-version: 16.x
+          node-version: 17.x
       - run: npm ci --no-optional
       - run: npm run prune
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2536e79b..0a0a7363 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,90 +5,75 @@ on:
     branches:
       - main
 jobs:
-  test-node17:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: use node.js v17.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 17.x
-      - run: npm ci --no-optional
-      - run: npm test
-  test-node16:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: use node.js v16.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 16.x
-      - run: npm ci --no-optional
-      - run: npm test
-  test-node14:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: use node.js v14.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 14.x
-      - run: npm ci --no-optional
-      - run: npm test
-  test-test262:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          submodules: true
-      - name: use node.js v17.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 17.x
-      - run: npm ci
-      - run: npm run test262
-        env:
-          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
-  test-test262-opt:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          submodules: true
-      - name: use node.js v17.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 17.x
-      - run: npm ci
-      - run: npm run test262
-        env:
-          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
-          NODE_ENV: production
-  test-test262-es5:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          submodules: true
-      - name: use node.js v17.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 17.x
-      - run: npm ci
-      - run: npm run test262
-        env:
-          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
-          NODE_ENV: production
-          TRANSPILE: '1'
-  test-validstrings:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - name: use node.js v16.x
-        uses: actions/setup-node@v1
-        with:
-          node-version: 16.x
-      - run: npm ci
-      - run: |
-          npm ci
-          npm run testValidStrings
+  test_demitasse_matrix:
+    strategy:
+      matrix:
+        version:
+          - 17.x
+          - 16.x
+          - 14.x
+    uses: ./.github/workflows/build_and_test.yml
+    with:
+      node-version-for-testing: ${{ matrix.version }}
+      test-cmd: npm run test_nobuild
+  test_validstrings:
+    uses: ./.github/workflows/build_and_test.yml
+    with:
+      test-cmd: npm run testValidStrings_nobuild
+  # test-test262:
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #     - uses: actions/checkout@v2
+  #       with:
+  #         submodules: true
+  #     - name: use node.js v17.x
+  #       uses: actions/setup-node@v1
+  #       with:
+  #         node-version: 17.x
+  #     - run: npm ci
+  #     - run: npm run test262
+  #       env:
+  #         HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+  # test-test262-opt:
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #     - uses: actions/checkout@v2
+  #       with:
+  #         submodules: true
+  #     - name: use node.js v17.x
+  #       uses: actions/setup-node@v1
+  #       with:
+  #         node-version: 17.x
+  #     - run: npm ci
+  #     - run: npm run test262
+  #       env:
+  #         HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+  #         NODE_ENV: production
+  # test-test262-es5:
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #     - uses: actions/checkout@v2
+  #       with:
+  #         submodules: true
+  #     - name: use node.js v17.x
+  #       uses: actions/setup-node@v1
+  #       with:
+  #         node-version: 17.x
+  #     - run: npm ci
+  #     - run: npm run test262
+  #       env:
+  #         HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+  #         NODE_ENV: production
+  #         TRANSPILE: "1"
+  # test-validstrings:
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #     - uses: actions/checkout@v2
+  #     - name: use node.js v16.x
+  #       uses: actions/setup-node@v1
+  #       with:
+  #         node-version: 16.x
+  #     - run: npm ci
+  #     - run: |
+  #         npm ci
+  #         npm run testValidStrings
diff --git a/package.json b/package.json
index aed9a264..87a5c3c6 100644
--- a/package.json
+++ b/package.json
@@ -24,9 +24,12 @@
   },
   "types": "./index.d.ts",
   "scripts": {
-    "test": "npm run build && node --no-warnings --experimental-modules --experimental-specifier-resolution=node --icu-data-dir node_modules/full-icu --loader ./test/resolve.source.mjs ./test/all.mjs",
-    "test262": "TEST262=1 npm run build && ./test/test262.sh",
-    "testValidStrings": "npm run build && node --experimental-modules --experimental-specifier-resolution=node --no-warnings --icu-data-dir ./node_modules/full-icu/ --loader ./test/resolve.source.mjs test/validStrings.mjs",
+    "test": "npm run build && npm run test_nobuild",
+    "test_nobuild": "node --no-warnings --experimental-modules --experimental-specifier-resolution=node --icu-data-dir node_modules/full-icu --loader ./test/resolve.source.mjs ./test/all.mjs",
+    "test262": "TEST262=1 npm run build && npm run test262_nobuild",
+    "test262_nobuild": "./test/test262.sh",
+    "testValidStrings": "npm run build && npm run testValidStrings_nobuild",
+    "testValidStrings_nobuild": "node --experimental-modules --experimental-specifier-resolution=node --no-warnings --icu-data-dir ./node_modules/full-icu/ --loader ./test/resolve.source.mjs test/validStrings.mjs",
     "build": "rm -rf dist/* tsc-out/* && tsc && rollup -c rollup.config.js",
     "prepare": "npm run build",
     "prepublishOnly": "node copy-types.mjs && npm run build",