Migrate benchmarks to vitest bench

.eslintignore

@@ -1,3 +1,3 @@
-benchmarks/
+legacy/
 dist/
 docs/

.gitignore

@@ -106,5 +106,5 @@ dist
 # TypeDoc
 docs
 
-# Benchmark
-benchmarks
+# Compiled legacy artifacts
+legacy

package.json

@@ -27,13 +27,11 @@
   ],
   "types": "dist/index.d.ts",
   "devDependencies": {
-    "@types/benchmark": "^2.1.5",
-    "@types/node": "^20.10.1",
-    "benchmark": "^2.1.4",
-    "gts": "^5.2.0",
-    "typedoc": "^0.25.4",
-    "typescript": "^5.3.2",
-    "vitest": "^0.34.6"
+    "@types/node": "^20.12.7",
+    "gts": "^5.3.0",
+    "typedoc": "^0.25.13",
+    "typescript": "^5.4.5",
+    "vitest": "^1.5.0"
   },
   "scripts": {
     "lint": "gts lint",
@@ -44,13 +42,10 @@
     "pretest": "npm run compile",
     "posttest": "npm run lint",
     "test": "vitest",
-    "doc": "typedoc src/index.ts . --name xen-dev-utils",
-    "premonzo-benchmark": "tsc -p tsconfig-benchmark.json",
-    "monzo-benchmark": "node benchmarks/__benchmarks__/monzo.mark.js",
-    "preprimes-benchmark": "tsc -p tsconfig-benchmark.json",
-    "primes-benchmark": "node benchmarks/__benchmarks__/primes.mark.js",
-    "prefraction-benchmark": "tsc -p tsconfig-benchmark.json",
-    "fraction-benchmark": "node benchmarks/__benchmarks__/fraction.mark.js"
+    "compile-legacy": "tsc -p tsconfig-legacy.json",
+    "prebench": "npm run compile && npm run compile-legacy",
+    "bench": "vitest bench",
+    "doc": "typedoc src/index.ts . --name xen-dev-utils"
   },
   "engines": {
     "node": ">=10.6.0"

src/__benchmarks__/monzo.bench.ts

@@ -0,0 +1,33 @@
+import {describe, bench} from 'vitest';
+
+// It's important to use the distributed versions for a realistic comparison
+import {toMonzoLegacy, primeLimitLegacy} from '../../legacy/legacy';
+import {toMonzo, primeLimit} from '../../dist';
+
+function randInt() {
+  return Math.ceil(Math.random() * 1000000000);
+}
+
+describe('Number to prime exponent vector conversion', () => {
+  bench('Old implementation', () => {
+    try {
+      toMonzoLegacy(randInt());
+    } catch {}
+  });
+
+  bench('Using probes without division', () => {
+    try {
+      toMonzo(randInt());
+    } catch {}
+  });
+});
+
+describe('Prime limit calculator', () => {
+  bench('Old implementation', () => {
+    primeLimitLegacy(randInt());
+  });
+
+  bench('New implementation', () => {
+    primeLimit(randInt());
+  });
+});