Generator performance

babel.config.js

@@ -179,6 +179,10 @@ module.exports = function (api) {
         plugins: ["babel-plugin-transform-charcodes"],
         assumptions: parserAssumptions,
       },
+      {
+        test: ["packages/babel-generator"].map(normalize),
+        plugins: ["babel-plugin-transform-charcodes"],
+      },
       convertESM && {
         test: [
           "./packages/babel-cli",

packages/babel-generator/benchmark/many-empty-statements/bench.mjs

@@ -0,0 +1,25 @@
+import Benchmark from "benchmark";
+import baseline from "@babel-baseline/generator";
+import current from "../../lib/index.js";
+import parser from "@babel/parser";
+import { report } from "../util.mjs";
+
+const suite = new Benchmark.Suite();
+
+function createInput(length) {
+  return parser.parse(";".repeat(length));
+}
+
+function benchCases(name, implementation, options) {
+  for (const length of [256, 512, 1024, 2048]) {
+    const input = createInput(length);
+    suite.add(`${name} ${length} empty statements`, () => {
+      implementation(input, options);
+    });
+  }
+}
+
+benchCases("baseline", baseline.default);
+benchCases("current", current.default);
+
+suite.on("cycle", report).run();

packages/babel-generator/benchmark/many-identifiers/1-length.mjs

@@ -0,0 +1,25 @@
+import Benchmark from "benchmark";
+import baseline from "@babel-baseline/generator";
+import current from "../../lib/index.js";
+import parser from "@babel/parser";
+import { report } from "../util.mjs";
+
+const suite = new Benchmark.Suite();
+
+function createInput(length) {
+  return parser.parse("a;".repeat(length));
+}
+
+function benchCases(name, implementation, options) {
+  for (const length of [256, 512, 1024, 2048]) {
+    const input = createInput(length);
+    suite.add(`${name} ${length} 1-length identifiers`, () => {
+      implementation(input, options);
+    });
+  }
+}
+
+benchCases("baseline", baseline.default);
+benchCases("current", current.default);
+
+suite.on("cycle", report).run();

packages/babel-generator/benchmark/many-identifiers/25-length.mjs

@@ -0,0 +1,25 @@
+import Benchmark from "benchmark";
+import baseline from "@babel-baseline/generator";
+import current from "../../lib/index.js";
+import parser from "@babel/parser";
+import { report } from "../util.mjs";
+
+const suite = new Benchmark.Suite();
+
+function createInput(length) {
+  return parser.parse("parseMaybeImportAssertion;".repeat(length));
+}
+
+function benchCases(name, implementation, options) {
+  for (const length of [256, 512, 1024, 2048]) {
+    const input = createInput(length);
+    suite.add(`${name} ${length} 25-length identifiers`, () => {
+      implementation(input, options);
+    });
+  }
+}
+
+benchCases("baseline", baseline.default);
+benchCases("current", current.default);
+
+suite.on("cycle", report).run();