[Tests] run npx ls-engines in tests

Author: ljharb

.github/workflows/node-4+.yml

@@ -81,6 +81,8 @@ jobs:
           skip-ls-check: ${{ matrix.node-version < 10 && true || false }}
         env:
           NPM_CONFIG_LEGACY_PEER_DEPS: true
+      - run: npx ls-engines
+        if: ${{ matrix.node-version >= 12 }}
       - run: npm run unit-test
       - uses: codecov/codecov-action@v1
 

.github/workflows/node-pretest.yml

@@ -27,5 +27,6 @@ jobs:
           node-version: 'lts/*'
         env:
           NPM_CONFIG_LEGACY_PEER_DEPS: true
+      - run: npx ls-engines
       - run: echo 'legacy-peer-deps=true' >> .npmrc
       - run: npm run posttest

package.json

@@ -65,6 +65,7 @@
     "eslint-scope": "^3.7.3",
     "espree": "^3.5.4",
     "istanbul": "^0.4.5",
+    "ls-engines": "^0.6.1",
     "markdown-magic": "^2.5.2",
     "mocha": "^5.2.0",
     "sinon": "^7.5.0",