test: add benchmark script

.eslintrc.json

@@ -8,8 +8,7 @@
   "env": {
     "node": true,
     "mocha": true,
-    "es2020": true,
-    "browser": true
+    "es2020": true
   },
   "overrides": [
     {

package.json

@@ -6,10 +6,14 @@
   "devDependencies": {
     "@commitlint/cli": "^16.2.3",
     "@commitlint/config-conventional": "^16.2.1",
+    "@types/benchmark": "^2.1.1",
+    "@types/degit": "^2.8.3",
     "@types/mocha": "^9.1.0",
     "@types/node": "^17.0.21",
     "@typescript-eslint/eslint-plugin": "^5.15.0",
     "@typescript-eslint/parser": "^5.15.0",
+    "benchmark": "^2.1.4",
+    "degit": "^2.8.4",
     "esbuild": "0.14.27",
     "esbuild-register": "^3.3.2",
     "eslint": "^8.11.0",
@@ -56,6 +60,7 @@
     "url": "https://github.com/marko-js/htmljs-parser.git"
   },
   "scripts": {
+    "bench": "node -r esbuild-register ./src/__tests__/bench",
     "build": "tsc -b && node -r esbuild-register build",
     "ci:test": "nyc npm run mocha -- --forbid-pending --forbid-only",
     "format": "npm run lint:eslint -- --fix && npm run lint:prettier -- --write && (fixpack || true)",

src/__tests__/bench.ts

@@ -0,0 +1,88 @@
+import fs from "fs";
+import os from "os";
+import path from "path";
+import cp from "child_process";
+import degit from "degit";
+import Benchmark from "benchmark";
+import { repository } from "../../package.json";
+import { createParser } from "..";
+
+const FIXTURES = path.join(__dirname, "fixtures");
+const GREP = new RegExp(process.env.GREP || ".", "g");
+const COMPARE = process.env.COMPARE;
+
+(async () => {
+  let altParser:
+    | undefined
+    | {
+        createParser(handlers: unknown): {
+          parse(src: string, filename: string): void;
+        };
+      };
+
+  if (COMPARE) {
+    const tempDir = await fs.promises.mkdtemp(
+      path.join(os.tmpdir(), "htmljs-parser-bench")
+    );
+    await degit(`${repository.url}#${COMPARE}`).clone(tempDir);
+    await new Promise<void>((resolve, reject) => {
+      cp.exec("npm ci && npm run --if-present build", { cwd: tempDir }, (err) =>
+        err ? reject(err) : resolve()
+      );
+    });
+
+    altParser = require(tempDir);
+  }
+
+  for (const entry of fs.readdirSync(FIXTURES)) {
+    const filename = path.join(FIXTURES, entry, "input.marko");
+    if (!GREP.test(entry)) continue;
+
+    const src = await fs.promises.readFile(filename, "utf-8");
+    const suite = new Benchmark.Suite();
+    suite.add(entry, () => {
+      const parser = createParser({
+        onError() {},
+        onText() {},
+        onCDATA() {},
+        onDoctype() {},
+        onDeclaration() {},
+        onComment() {},
+        onTagName() {},
+        onTagShorthandId() {},
+        onTagShorthandClass() {},
+        onTagVar() {},
+        onTagArgs() {},
+        onTagParams() {},
+        onAttrName() {},
+        onAttrArgs() {},
+        onAttrValue() {},
+        onAttrMethod() {},
+        onAttrSpread() {},
+        onOpenTagEnd() {},
+        onCloseTag() {},
+        onScriptlet() {},
+      });
+      parser.parse(src, filename);
+    });
+
+    if (altParser) {
+      suite.add(`${entry} #${COMPARE}`, () => {
+        const parser = altParser!.createParser({});
+        parser.parse(src, filename);
+      });
+    }
+
+    suite.on("cycle", (event: Benchmark.Event) => {
+      console.log(String(event.target));
+    });
+
+    const pending = new Promise((r) => suite.on("complete", r));
+    suite.run();
+    await pending;
+
+    if (altParser) {
+      console.log(`Fastest is ${suite.filter("fastest").map("name")}`);
+    }
+  }
+})();