perf: Make VISITOR_KEYS etc. faster to access (babel#16918)

* perf * review * review
nicolo-ribaudo · Oct 20, 2024 · d20b314 · d20b314
1 parent 831396d
commit d20b314
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Showing 4 changed files with 30 additions and 36 deletions.
diff --git a/packages/babel-parser/src/options.ts b/packages/babel-parser/src/options.ts
@@ -93,16 +93,21 @@ export const defaultOptions: OptionsWithDefaults = {
 // Interpret and default an options object
 
 export function getOptions(opts?: Options | null): OptionsWithDefaults {
+  // https://github.com/babel/babel/pull/16918
+  // `options` is accessed frequently, please make sure it is a fast object.
+  // `%ToFastProperties` can make it a fast object, but the performance is the same as the slow object.
+  const options: any = { ...defaultOptions };
+
   if (opts == null) {
-    return { ...defaultOptions };
+    return options;
   }
   if (opts.annexB != null && opts.annexB !== false) {
     throw new Error("The `annexB` option can only be set to `false`.");
   }
 
-  const options: any = {};
   for (const key of Object.keys(defaultOptions) as (keyof Options)[]) {
-    options[key] = opts[key] ?? defaultOptions[key];
+    if (opts[key] != null) options[key] = opts[key];
   }
+
   return options;
 }
diff --git a/packages/babel-types/package.json b/packages/babel-types/package.json
@@ -25,8 +25,7 @@
   },
   "dependencies": {
     "@babel/helper-string-parser": "workspace:^",
-    "@babel/helper-validator-identifier": "workspace:^",
-    "to-fast-properties": "condition:BABEL_8_BREAKING ? ^3.0.0 : ^2.0.0"
+    "@babel/helper-validator-identifier": "workspace:^"
   },
   "devDependencies": {
     "@babel/generator": "workspace:^",

diff --git a/packages/babel-types/src/definitions/index.ts b/packages/babel-types/src/definitions/index.ts
@@ -1,4 +1,3 @@
-import toFastProperties from "to-fast-properties";
 import "./core.ts";
 import "./flow.ts";
 import "./jsx.ts";
@@ -29,15 +28,17 @@ import { DEPRECATED_ALIASES } from "./deprecated-aliases.ts";
 });
 
 // We do this here, because at this point the visitor keys should be ready and setup
-toFastProperties(VISITOR_KEYS);
-toFastProperties(ALIAS_KEYS);
-toFastProperties(FLIPPED_ALIAS_KEYS);
-toFastProperties(NODE_FIELDS);
-toFastProperties(BUILDER_KEYS);
-toFastProperties(DEPRECATED_KEYS);
+// `%ToFastProperties` no longer improves performance, so we use another approach.
+const _VISITOR_KEYS = { ...VISITOR_KEYS };
+const _ALIAS_KEYS = { ...ALIAS_KEYS };
+const _FLIPPED_ALIAS_KEYS = { ...FLIPPED_ALIAS_KEYS };
+const _NODE_FIELDS = { ...NODE_FIELDS };
+const _BUILDER_KEYS = { ...BUILDER_KEYS };
+const _DEPRECATED_KEYS = { ...DEPRECATED_KEYS };
+const _NODE_PARENT_VALIDATIONS = { ...NODE_PARENT_VALIDATIONS };
 
-toFastProperties(PLACEHOLDERS_ALIAS);
-toFastProperties(PLACEHOLDERS_FLIPPED_ALIAS);
+const _PLACEHOLDERS_ALIAS = { ...PLACEHOLDERS_ALIAS };
+const _PLACEHOLDERS_FLIPPED_ALIAS = { ...PLACEHOLDERS_FLIPPED_ALIAS };
 
 const TYPES: Array<string> = [].concat(
   Object.keys(VISITOR_KEYS),
@@ -46,17 +47,17 @@ const TYPES: Array<string> = [].concat(
 );
 
 export {
-  VISITOR_KEYS,
-  ALIAS_KEYS,
-  FLIPPED_ALIAS_KEYS,
-  NODE_FIELDS,
-  BUILDER_KEYS,
+  _VISITOR_KEYS as VISITOR_KEYS,
+  _ALIAS_KEYS as ALIAS_KEYS,
+  _FLIPPED_ALIAS_KEYS as FLIPPED_ALIAS_KEYS,
+  _NODE_FIELDS as NODE_FIELDS,
+  _BUILDER_KEYS as BUILDER_KEYS,
   DEPRECATED_ALIASES,
-  DEPRECATED_KEYS,
-  NODE_PARENT_VALIDATIONS,
+  _DEPRECATED_KEYS as DEPRECATED_KEYS,
+  _NODE_PARENT_VALIDATIONS as NODE_PARENT_VALIDATIONS,
   PLACEHOLDERS,
-  PLACEHOLDERS_ALIAS,
-  PLACEHOLDERS_FLIPPED_ALIAS,
+  _PLACEHOLDERS_ALIAS as PLACEHOLDERS_ALIAS,
+  _PLACEHOLDERS_FLIPPED_ALIAS as PLACEHOLDERS_FLIPPED_ALIAS,
   TYPES,
 };
 

diff --git a/yarn.lock b/yarn.lock
@@ -4257,7 +4257,6 @@ __metadata:
     "@babel/helper-validator-identifier": "workspace:^"
     "@babel/parser": "workspace:^"
     glob: "npm:^7.2.0"
-    to-fast-properties: "condition:BABEL_8_BREAKING ? ^3.0.0 : ^2.0.0"
   languageName: unknown
   linkType: soft
 
@@ -16234,30 +16233,20 @@ __metadata:
   languageName: node
   linkType: hard
 
-"to-fast-properties-BABEL_8_BREAKING-false@npm:to-fast-properties@^2.0.0, to-fast-properties@npm:^2.0.0":
+"to-fast-properties@npm:^2.0.0":
   version: 2.0.0
   resolution: "to-fast-properties@npm:2.0.0"
   checksum: 10/be2de62fe58ead94e3e592680052683b1ec986c72d589e7b21e5697f8744cdbf48c266fa72f6c15932894c10187b5f54573a3bcf7da0bfd964d5caf23d436168
   languageName: node
   linkType: hard
 
-"to-fast-properties-BABEL_8_BREAKING-true@npm:to-fast-properties@^3.0.0, to-fast-properties@npm:^3.0.0":
+"to-fast-properties@npm:^3.0.0":
   version: 3.0.1
   resolution: "to-fast-properties@npm:3.0.1"
   checksum: 10/66b79f2c0d420d116a4eeb781c87c8c6b2de426a15f16118759e706aa1111833b0c578355a1108514ada966c08f4dba0cb7994aca025d80a535a139f7a631e22
   languageName: node
   linkType: hard
 
-"to-fast-properties@condition:BABEL_8_BREAKING ? ^3.0.0 : ^2.0.0":
-  version: 0.0.0-condition-05bba4
-  resolution: "to-fast-properties@condition:BABEL_8_BREAKING?^3.0.0:^2.0.0#05bba4"
-  dependencies:
-    to-fast-properties-BABEL_8_BREAKING-false: "npm:to-fast-properties@^2.0.0"
-    to-fast-properties-BABEL_8_BREAKING-true: "npm:to-fast-properties@^3.0.0"
-  checksum: 10/9baff3822ec19add946c04335d91f8b3cc387c25e7879e8ba5c3a6879a9371bce46866e42b90058b7d89dd45ffa60c433086affb347df19b9a45eac201f9385a
-  languageName: node
-  linkType: hard
-
 "to-object-path@npm:^0.3.0":
   version: 0.3.0
   resolution: "to-object-path@npm:0.3.0"