Add some basic decoding benchmark

Author: szuend

bench/common-formatted.min.js.map

@@ -0,0 +1,32 @@
+// Copyright 2025 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import { expandGlob } from "jsr:@std/fs";
+import { format } from "jsr:@std/fmt/bytes";
+
+import { decode, DecodeMode } from "../mod.ts";
+
+const BENCHMARKS = await (async () => {
+  const result = [];
+  for await (const file of expandGlob("*.js.map", { root: import.meta.dirname })) {
+    const mapContent = Deno.readTextFileSync(file.path);
+    const mapJson = JSON.parse(mapContent);
+    result.push({
+      name: file.name,
+      mapJson,
+      size: mapContent.length,
+    });
+  }
+  return result;
+})();
+
+for (const {name, mapJson, size} of BENCHMARKS) {
+  Deno.bench(`${name}, lax, ${format(size)}`, () => {
+    decode(mapJson, { mode: DecodeMode.LOOSE });
+  });
+
+  Deno.bench(`${name}, strict, ${format(size)}`, () => {
+    decode(mapJson, { mode: DecodeMode.STRICT });
+  });
+}