test: add bundle size test

Author: pi0

pnpm-lock.yaml

@@ -0,0 +1,52 @@
+import { describe, it, expect } from "vitest";
+import { build } from "esbuild";
+import { fileURLToPath } from "node:url";
+import zlib from "node:zlib";
+
+describe("benchmark", () => {
+  it("no side effects", async () => {
+    const code = /* js */ `
+      import { createHooks } from "../src/index.ts";
+    `;
+    const { bytes, output } = await getBundleSize(code);
+    expect(output).toEqual("");
+    expect(bytes).toBe(0);
+  });
+
+  it("new Hookable()", async () => {
+    const code = /* js */ `
+      import { Hookable } from "../src/index.ts";
+      export default new Hookable()
+    `;
+    const { bytes, gzipSize } = await getBundleSize(code);
+    // console.log("new Hookable():", { bytes, gzipSize });
+    expect(bytes).toBeLessThan(3000);
+    expect(gzipSize).toBeLessThan(1200);
+  });
+});
+
+async function getBundleSize(code: string) {
+  const res = await build({
+    bundle: true,
+    metafile: true,
+    write: false,
+    minify: true,
+    format: "esm",
+    platform: "node",
+    outfile: "index.mjs",
+    stdin: {
+      contents: code,
+      resolveDir: fileURLToPath(new URL(".", import.meta.url)),
+      sourcefile: "index.mjs",
+      loader: "js",
+    },
+  });
+
+  const { bytes } = res.metafile.outputs["index.mjs"];
+  const gzipSize = zlib.gzipSync(res.outputFiles[0].text).byteLength;
+  return {
+    bytes,
+    gzipSize,
+    output: new TextDecoder().decode(res.outputFiles[0].contents),
+  };
+}