[Tests] add nyc; increase coverage

Author: ljharb

.nycrc

@@ -0,0 +1,16 @@
+{
+	"all": true,
+	"reporter": [
+		"html",
+		"text",
+		"lcov"
+	],
+	"exclude": [
+		"coverage",
+		"eslint.config.mjs",
+		"example",
+		"scripts",
+		"test",
+		"**/*.d.*ts"
+	]
+}

package.json

@@ -36,7 +36,7 @@
 		"lint": "eslint .",
 		"postlint": "tsc -p . && attw -P",
 		"pretests-only": "npm run submodule:update && cd ./test/resolver/nested_symlinks && node mylib/sync && node mylib/async",
-		"tests-only": "tape test/*.js",
+		"tests-only": "nyc tape test/*.js",
 		"pretest": "npm run lint",
 		"test": "npm run --silent tests-only",
 		"posttest": "npm run test:multirepo && npx npm@\">= 10.2\" audit --production",
@@ -74,6 +74,7 @@
 		"mkdirp": "^0.5.6",
 		"mv": "^2.1.1",
 		"npmignore": "^0.3.5",
+		"nyc": "^10.3.2",
 		"rimraf": "^2.7.1",
 		"safe-publish-latest": "^2.0.0",
 		"tap": "^0.4.13",