Some minor parser performance improvements for ts

Gulpfile.mjs

@@ -244,6 +244,7 @@ function createWorker(useWorker) {
  return require("./babel-worker.cjs");
  }
  const worker = new JestWorker(require.resolve("./babel-worker.cjs"), {
+ enableWorkerThreads: true,
  numWorkers,
  exposedMethods: ["transform"],
  });
@@ -942,7 +943,10 @@ gulp.task(
 );
 
 function watch() {
- gulp.watch(defaultSourcesGlob, gulp.task("build-no-bundle-watch"));
+ gulp.watch(
+ defaultSourcesGlob,
+ gulp.series("build-no-bundle-watch", "build-cjs-bundles")
+ );
  gulp.watch(babelStandalonePluginConfigGlob, gulp.task("generate-standalone"));
  gulp.watch(buildTypingsWatchGlob, gulp.task("generate-type-helpers"));
  gulp.watch(

benchmark/babel-parser/real-case-ts/bench.mjs

@@ -1,10 +1,11 @@
-import Benchmark from "benchmark";
-import baseline from "@babel-baseline/parser";
-import current from "@babel/parser";
-import { report } from "../../util.mjs";
-import { readFileSync } from "fs";
+import { copyFileSync, readFileSync, rmSync } from "fs";
+// eslint-disable-next-line import/no-extraneous-dependencies
+import { commonJS } from "$repo-utils";
+import { Benchmark } from "../../util.mjs";
 
-const suite = new Benchmark.Suite();
+const { require } = commonJS(import.meta.url);
+
+const benchmark = new Benchmark();
 
 function createInput(length) {
  return readFileSync(new URL("ts-parser.txt", import.meta.url), {
@@ -19,7 +20,7 @@ const inputs = [1].map(length => ({
 
 function benchCases(name, implementation, options) {
  for (const input of inputs) {
- suite.add(`${name} ${input.tag} typescript parser.ts`, () => {
+ benchmark.add(`${name} ${input.tag} typescript parser.ts`, () => {
  implementation(input.body, {
  sourceType: "module",
  plugins: ["typescript"],
@@ -28,10 +29,25 @@ function benchCases(name, implementation, options) {
  });
  }
 }
+copyFileSync(
+ require.resolve("@babel-baseline/parser"),
+ "./parser-baseline.cjs"
+);
+copyFileSync(
+ "../../../packages/babel-parser/lib/index.js",
+ "./parser-current.cjs"
+);
+
+const baseline = require("./parser-baseline.cjs");
+const current = require("./parser-current.cjs");
 
 benchCases("current", current.parse);
 benchCases("baseline", baseline.parse);
 benchCases("current", current.parse);
 benchCases("baseline", baseline.parse);
 
-suite.on("cycle", report).run();
+benchmark.suite.on("complete", () => {
+ rmSync("./parser-current.cjs");
+ rmSync("./parser-baseline.cjs");
+});
+benchmark.run();

benchmark/package.json

@@ -3,13 +3,13 @@
  "private": true,
  "type": "module",
  "devDependencies": {
- "@babel-baseline/core": "npm:@babel/core@7.23.2",
- "@babel-baseline/generator": "npm:@babel/generator@7.23.0",
- "@babel-baseline/helper-compilation-targets": "npm:@babel/helper-compilation-targets@7.22.15",
+ "@babel-baseline/core": "npm:@babel/core@7.24.4",
+ "@babel-baseline/generator": "npm:@babel/generator@7.24.4",
+ "@babel-baseline/helper-compilation-targets": "npm:@babel/helper-compilation-targets@7.23.6",
  "@babel-baseline/helper-validator-identifier": "npm:@babel/[email protected]",
- "@babel-baseline/parser": "npm:@babel/parser@7.23.0",
- "@babel-baseline/traverse": "npm:@babel/traverse@7.23.2",
- "@babel-baseline/types": "npm:@babel/types@7.23.0",
+ "@babel-baseline/parser": "npm:@babel/parser@7.24.4",
+ "@babel-baseline/traverse": "npm:@babel/traverse@7.24.1",
+ "@babel-baseline/types": "npm:@babel/types@7.24.0",
  "@babel/core": "workspace:^",
  "@babel/generator": "workspace:^",
  "@babel/helper-compilation-targets": "workspace:^",

packages/babel-parser/src/index.ts

@@ -1,18 +1,16 @@
 import type { Options } from "./options.ts";
 import {
- hasPlugin,
  validatePlugins,
  mixinPluginNames,
  mixinPlugins,
- type PluginList,
 } from "./plugin-utils.ts";
 import type {
  PluginConfig as ParserPlugin,
  FlowPluginOptions,
  RecordAndTuplePluginOptions,
  PipelineOperatorPluginOptions,
 } from "./typings.ts";
-import Parser from "./parser/index.ts";
+import Parser, { type PluginsMap } from "./parser/index.ts";
 
 import type { ExportedTokenType } from "./tokenizer/types.ts";
 import {
@@ -92,33 +90,47 @@ export const tokTypes = generateExportedTokenTypes(internalTokenTypes);
 
 function getParser(options: Options | undefined | null, input: string): Parser {
  let cls = Parser;
+ const pluginsMap: PluginsMap = new Map();
  if (options?.plugins) {
- validatePlugins(options.plugins);
- cls = getParserClass(options.plugins);
+ for (const plugin of options.plugins) {
+ let name, opts;
+ if (typeof plugin === "string") {
+ name = plugin;
+ } else {
+ [name, opts] = plugin;
+ }
+ if (!pluginsMap.has(name)) {
+ pluginsMap.set(name, opts || {});
+ }
+ }
+ validatePlugins(pluginsMap);
+ cls = getParserClass(pluginsMap);
  }
 
- return new cls(options, input);
+ return new cls(options, input, pluginsMap);
 }
 
-const parserClassCache: { [key: string]: { new (...args: any): Parser } } = {};
+const parserClassCache = new Map<string, { new (...args: any): Parser }>();
 
 /** Get a Parser class with plugins applied. */
-function getParserClass(pluginsFromOptions: PluginList): {
+function getParserClass(pluginsMap: Map<string, any>): {
  new (...args: any): Parser;
 } {
- const pluginList = mixinPluginNames.filter(name =>
- hasPlugin(pluginsFromOptions, name),
- );
-
- const key = pluginList.join("/");
- let cls = parserClassCache[key];
+ const pluginList = [];
+ for (const name of mixinPluginNames) {
+ if (pluginsMap.has(name)) {
+ pluginList.push(name);
+ }
+ }
+ const key = pluginList.join("|");
+ let cls = parserClassCache.get(key);
  if (!cls) {
  cls = Parser;
  for (const plugin of pluginList) {
  // @ts-expect-error todo(flow->ts)
  cls = mixinPlugins[plugin](cls);
  }
- parserClassCache[key] = cls;
+ parserClassCache.set(key, cls);
  }
  return cls;
 }

packages/babel-parser/src/parse-error.ts

@@ -33,7 +33,7 @@ interface ParseErrorSpecification<ErrorDetails> {
 
  // We should consider removing this as it now just contains the same
  // information as `loc.index`.
- // pos: number;
+ pos: number;
 }
 
 export type ParseError<ErrorDetails> = SyntaxError &
@@ -68,13 +68,23 @@ function defineHidden(obj: object, key: string, value: unknown) {
 
 function toParseErrorConstructor<ErrorDetails extends object>({
  toMessage,
- ...properties
+ code,
+ reasonCode,
+ syntaxPlugin,
 }: ParseErrorCredentials<ErrorDetails>): ParseErrorConstructor<ErrorDetails> {
+ const hasMissingPlugin =
+ reasonCode === "MissingPlugin" || reasonCode === "MissingOneOfPlugins";
  return function constructor(loc: Position, details: ErrorDetails) {
- const error = new SyntaxError();
- Object.assign(error, properties, { loc, pos: loc.index });
- if ("missingPlugin" in details) {
- Object.assign(error, { missingPlugin: details.missingPlugin });
+ const error: ParseError<ErrorDetails> = new SyntaxError() as any;
+
+ error.code = code as ParseErrorCode;
+ error.reasonCode = reasonCode;
+ error.loc = loc;
+ error.pos = loc.index;
+
+ error.syntaxPlugin = syntaxPlugin;
+ if (hasMissingPlugin) {
+ error.missingPlugin = (details as any).missingPlugin;
  }
 
  type Overrides = {
@@ -103,7 +113,7 @@ function toParseErrorConstructor<ErrorDetails extends object>({
  },
  });
 
- return error as ParseError<ErrorDetails>;
+ return error;
  };
 }
 

packages/babel-parser/src/parser/expression.ts

@@ -333,9 +333,7 @@ export default abstract class ExpressionParser extends LValParser {
 
  this.next();
  node.right = this.parseMaybeAssign();
- this.checkLVal(left, {
- in: this.finishNode(node, "AssignmentExpression"),
- });
+ this.checkLVal(left, this.finishNode(node, "AssignmentExpression"));
  // @ts-expect-error todo(flow->ts) improve node types
  return node;
  } else if (ownExpressionErrors) {
@@ -676,9 +674,10 @@ export default abstract class ExpressionParser extends LValParser {
  ): N.Expression {
  if (update) {
  const updateExpressionNode = node as Undone<N.UpdateExpression>;
- this.checkLVal(updateExpressionNode.argument, {
- in: this.finishNode(updateExpressionNode, "UpdateExpression"),
- });
+ this.checkLVal(
+ updateExpressionNode.argument,
+ this.finishNode(updateExpressionNode, "UpdateExpression"),
+ );
  return node;
  }
 
@@ -691,9 +690,7 @@ export default abstract class ExpressionParser extends LValParser {
  node.prefix = false;
  node.argument = expr;
  this.next();
- this.checkLVal(expr, {
- in: (expr = this.finishNode(node, "UpdateExpression")),
- });
+ this.checkLVal(expr, (expr = this.finishNode(node, "UpdateExpression")));
  }
  return expr;
  }
@@ -2664,12 +2661,13 @@ export default abstract class ExpressionParser extends LValParser {
  // 1. https://tc39.es/ecma262/#prod-FormalParameters
  const formalParameters = { type: "FormalParameters" } as const;
  for (const param of node.params) {
- this.checkLVal(param, {
- in: formalParameters,
- binding: BindingFlag.TYPE_VAR,
+ this.checkLVal(
+ param,
+ formalParameters,
+ BindingFlag.TYPE_VAR,
  checkClashes,
  strictModeChanged,
- });
+ );
  }
  }
 

packages/babel-parser/src/parser/index.ts

@@ -1,6 +1,5 @@
 import type { Options } from "../options.ts";
 import type * as N from "../types.ts";
-import type { PluginList } from "../plugin-utils.ts";
 import { getOptions } from "../options.ts";
 import StatementParser from "./statement.ts";
 import ScopeHandler from "../util/scope.ts";
@@ -19,13 +18,17 @@ export default class Parser extends StatementParser {
  // node: N.JSXOpeningElement,
  // ): N.JSXOpeningElement;
 
- constructor(options: Options | undefined | null, input: string) {
+ constructor(
+ options: Options | undefined | null,
+ input: string,
+ pluginsMap: PluginsMap,
+ ) {
  options = getOptions(options);
  super(options, input);
 
  this.options = options;
  this.initializeScopes();
- this.plugins = pluginsMap(this.options.plugins);
+ this.plugins = pluginsMap;
  this.filename = options.sourceFilename;
  }
 
@@ -48,12 +51,3 @@ export default class Parser extends StatementParser {
  return file as N.File;
  }
 }
-
-function pluginsMap(plugins: PluginList): PluginsMap {
- const pluginMap: PluginsMap = new Map();
- for (const plugin of plugins) {
- const [name, options] = Array.isArray(plugin) ? plugin : [plugin, {}];
- if (!pluginMap.has(name)) pluginMap.set(name, options || {});
- }
- return pluginMap;
-}