[Tests] add nyc for coverage

.nycrc

@@ -0,0 +1,17 @@
+{
+  "extension": [
+    ".js",
+    ".cjs",
+    ".mjs"
+  ],
+  "all": true,
+  "check-coverage": false,
+  "reporter": ["text-summary", "text", "html", "json", "lcov"],
+  "exclude": [
+    "coverage",
+    "example",
+    "test"
+  ],
+  "sourceMap": true,
+  "instrument": true
+}

package.json

@@ -10,13 +10,13 @@
   },
   "scripts": {
     "prepack": "npmignore --auto --commentLines=autogenerated",
-    "prepublishOnly": "safe-publish-latest",
     "prepublish": "not-in-publish || npm run prepublishOnly",
+    "prepublishOnly": "safe-publish-latest",
     "pretest": "npm run lint",
-    "lint": "eslint .",
-    "tests-only": "tape test/*",
+    "lint": "eslint --ext=js,mjs .",
+    "tests-only": "nyc tape 'test/**/*.js'",
     "test": "npm run tests-only",
-    "posttest": "npx aud",
+    "posttest": "aud --production",
     "version": "auto-changelog && git add CHANGELOG.md",
     "postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
   },
@@ -30,10 +30,12 @@
   },
   "devDependencies": {
     "@ljharb/eslint-config": "^21.1.0",
+    "aud": "^2.0.3",
     "auto-changelog": "^2.4.0",
     "eslint": "=8.8.0",
     "in-publish": "^2.0.1",
     "npmignore": "^0.3.0",
+    "nyc": "^10.3.2",
     "safe-publish-latest": "^2.0.0",
     "tape": "^5.7.1"
   },