toolrunner should which tool before invoking (#220)

.github/workflows/unit-tests.yml

@@ -6,18 +6,27 @@ on:
   pull_request:
     paths-ignore:
       - '**.md'     
+
 jobs:
-  Ubuntu:
-    name: Run Ubuntu
-    runs-on: ubuntu-latest
+
+  build:
+    name: Build
+
+    strategy:
+      matrix:
+        runs-on: [ubuntu-latest, macOS-latest, windows-latest]
+      fail-fast: false
+
+    runs-on: ${{ matrix.runs-on }}
+
     steps:
     - name: Checkout
-      uses: actions/checkout@master
+      uses: actions/checkout@v1
 
-    - name: Set Node.js 10.x
+    - name: Set Node.js 12.x
       uses: actions/setup-node@master
       with:
-        node-version: 10.x
+        node-version: 12.x
 
     - name: npm install
       run: npm install
@@ -36,52 +45,3 @@ jobs:
 
     - name: Format
       run: npm run format-check
-  macOS:
-    name: Run macOS
-    runs-on: macos-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@master
-
-      - name: Set Node.js 10.x
-        uses: actions/setup-node@master
-        with:
-          node-version: 10.x
-
-      - name: npm install
-        run: npm install
-
-      - name: Bootstrap
-        run: npm run bootstrap
-
-      - name: Compile
-        run: npm run build
-
-      - name: npm test
-        run: npm test
-  Windows:
-    name: Run Windows
-    runs-on: windows-latest
-    steps:
-    - name: Checkout
-      uses: actions/checkout@master
-
-    - name: Set Node.js 10.x
-      uses: actions/setup-node@master
-      with:
-        node-version: 10.x
-
-    - name: npm install
-      run: npm install
-
-    - name: Bootstrap
-      run: npm run bootstrap
-
-    - name: Compile
-      run: npm run build
-
-    # TODO: This currently ignores exec due to issues with Node and spawning on Windows, which I think is exacerbated by Jest.
-    # It doesn't seem to affect behavior in actions themselves, just when testing with Jest.
-    # See other similar issues here: https://github.com/nodejs/node/issues/25484
-    - name: npm test
-      run: npm run test-ci