Upgrade Ava to v4

node_modules/mem/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mem",
-  "version": "8.1.1",
+  "version": "9.0.2",
   "description": "Memoize functions - An optimization used to speed up consecutive function calls by caching the result of calls with identical input",
   "license": "MIT",
   "repository": "sindresorhus/mem",
@@ -10,19 +10,19 @@
     "email": "sindresorhus@gmail.com",
     "url": "https://sindresorhus.com"
   },
+  "type": "module",
+  "exports": "./dist/index.js",
   "engines": {
-    "node": ">=10"
+    "node": ">=12.20"
   },
   "scripts": {
-    "test": "xo && npm run build && tsd && ava",
+    "test": "xo && ava && npm run build && tsd",
     "build": "del-cli dist && tsc",
     "prepack": "npm run build"
   },
-  "main": "dist",
   "types": "dist/index.d.ts",
   "files": [
-    "dist/index.js",
-    "dist/index.d.ts"
+    "dist"
   ],
   "keywords": [
     "memoize",
@@ -39,30 +39,32 @@
   ],
   "dependencies": {
     "map-age-cleaner": "^0.1.3",
-    "mimic-fn": "^3.1.0"
+    "mimic-fn": "^4.0.0"
   },
   "devDependencies": {
     "@ava/typescript": "^1.1.1",
-    "@sindresorhus/tsconfig": "^0.7.0",
+    "@sindresorhus/tsconfig": "^1.0.2",
     "@types/serialize-javascript": "^4.0.0",
     "ava": "^3.15.0",
     "del-cli": "^3.0.1",
     "delay": "^4.4.0",
     "serialize-javascript": "^5.0.1",
+    "ts-node": "^10.1.0",
     "tsd": "^0.13.1",
-    "typescript": "^4.0.3",
-    "xo": "^0.38.2"
+    "typescript": "^4.3.5",
+    "xo": "^0.41.0"
   },
   "ava": {
-    "files": [
-      "test.ts"
-    ],
     "timeout": "1m",
-    "typescript": {
-      "rewritePaths": {
-        "./": "dist/"
-      }
-    }
+    "extensions": {
+      "ts": "module"
+    },
+    "nonSemVerExperiments": {
+      "configurableModuleFormat": true
+    },
+    "nodeArguments": [
+      "--loader=ts-node/esm"
+    ]
   },
   "xo": {
     "rules": {