Use const enum in babel-parser (#15793)

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

@@ -47,15 +47,7 @@ import {
   createPositionWithColumnOffset,
 } from "../util/location";
 import * as charCodes from "charcodes";
-import {
-  BIND_OUTSIDE,
-  BIND_VAR,
-  SCOPE_ARROW,
-  SCOPE_CLASS,
-  SCOPE_DIRECT_SUPER,
-  SCOPE_FUNCTION,
-  SCOPE_SUPER,
-} from "../util/scopeflags";
+import { ScopeFlag, BindingFlag } from "../util/scopeflags";
 import { ExpressionErrors } from "./util";
 import {
   PARAM_AWAIT,
@@ -2430,10 +2422,10 @@ export default abstract class ExpressionParser extends LValParser {
     this.initFunction(node, isAsync);
     node.generator = isGenerator;
     this.scope.enter(
-      SCOPE_FUNCTION |
-        SCOPE_SUPER |
-        (inClassScope ? SCOPE_CLASS : 0) |
-        (allowDirectSuper ? SCOPE_DIRECT_SUPER : 0),
+      ScopeFlag.FUNCTION |
+        ScopeFlag.SUPER |
+        (inClassScope ? ScopeFlag.CLASS : 0) |
+        (allowDirectSuper ? ScopeFlag.DIRECT_SUPER : 0),
     );
     this.prodParam.enter(functionFlags(isAsync, node.generator));
     this.parseFunctionParams(node, isConstructor);
@@ -2485,7 +2477,7 @@ export default abstract class ExpressionParser extends LValParser {
     isAsync: boolean,
     trailingCommaLoc?: Position | null,
   ): N.ArrowFunctionExpression {
-    this.scope.enter(SCOPE_FUNCTION | SCOPE_ARROW);
+    this.scope.enter(ScopeFlag.FUNCTION | ScopeFlag.ARROW);
     let flags = functionFlags(isAsync, false);
     // ConciseBody[In] :
     //   [lookahead ≠ {] ExpressionBody[?In, ~Await]
@@ -2591,7 +2583,11 @@ export default abstract class ExpressionParser extends LValParser {
 
           // Ensure the function name isn't a forbidden identifier in strict mode, e.g. 'eval'
           if (this.state.strict && node.id) {
-            this.checkIdentifier(node.id, BIND_OUTSIDE, strictModeChanged);
+            this.checkIdentifier(
+              node.id,
+              BindingFlag.TYPE_OUTSIDE,
+              strictModeChanged,
+            );
           }
         },
       );
@@ -2632,7 +2628,7 @@ export default abstract class ExpressionParser extends LValParser {
     for (const param of node.params) {
       this.checkLVal(param, {
         in: formalParameters,
-        binding: BIND_VAR,
+        binding: BindingFlag.TYPE_VAR,
         checkClashes,
         strictModeChanged,
       });

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

@@ -26,11 +26,7 @@ import {
   isStrictBindReservedWord,
 } from "../util/identifier";
 import { NodeUtils, type Undone } from "./node";
-import {
-  type BindingTypes,
-  BIND_NONE,
-  BIND_FLAGS_NO_LET_IN_LEXICAL,
-} from "../util/scopeflags";
+import { type BindingTypes, BindingFlag } from "../util/scopeflags";
 import type { ExpressionErrors } from "./util";
 import { Errors, type LValAncestor } from "../parse-error";
 import type Parser from "./index";
@@ -566,7 +562,7 @@ export default abstract class LValParser extends NodeUtils {
    *        if the check fails.
    * @param options.binding
    *        The desired binding type. If the given expression is an identifier
-   *        and `binding` is not `BIND_NONE`, `checkLVal` will register binding
+   *        and `binding` is not `BindingFlag.TYPE_NONE`, `checkLVal` will register binding
    *        to the parser scope See also `src/util/scopeflags.js`
    * @param options.checkClashes
    *        An optional string set to check if an identifier name is included.
@@ -585,7 +581,7 @@ export default abstract class LValParser extends NodeUtils {
     expression: Expression | ObjectMember | RestElement,
     {
       in: ancestor,
-      binding = BIND_NONE,
+      binding = BindingFlag.TYPE_NONE,
       checkClashes = false,
       strictModeChanged = false,
       hasParenthesizedAncestor = false,
@@ -605,7 +601,7 @@ export default abstract class LValParser extends NodeUtils {
     if (this.isObjectMethod(expression)) return;
 
     if (type === "MemberExpression") {
-      if (binding !== BIND_NONE) {
+      if (binding !== BindingFlag.TYPE_NONE) {
         this.raise(Errors.InvalidPropertyBindingPattern, { at: expression });
       }
       return;
@@ -641,7 +637,9 @@ export default abstract class LValParser extends NodeUtils {
     if (validity === true) return;
     if (validity === false) {
       const ParseErrorClass =
-        binding === BIND_NONE ? Errors.InvalidLhs : Errors.InvalidLhsBinding;
+        binding === BindingFlag.TYPE_NONE
+          ? Errors.InvalidLhs
+          : Errors.InvalidLhsBinding;
 
       this.raise(ParseErrorClass, { at: expression, ancestor });
       return;
@@ -682,7 +680,7 @@ export default abstract class LValParser extends NodeUtils {
         ? isStrictBindReservedWord(at.name, this.inModule)
         : isStrictBindOnlyReservedWord(at.name))
     ) {
-      if (bindingType === BIND_NONE) {
+      if (bindingType === BindingFlag.TYPE_NONE) {
         this.raise(Errors.StrictEvalArguments, { at, referenceName: at.name });
       } else {
         this.raise(Errors.StrictEvalArgumentsBinding, {
@@ -692,11 +690,11 @@ export default abstract class LValParser extends NodeUtils {
       }
     }
 
-    if (bindingType & BIND_FLAGS_NO_LET_IN_LEXICAL && at.name === "let") {
+    if (bindingType & BindingFlag.FLAG_NO_LET_IN_LEXICAL && at.name === "let") {
       this.raise(Errors.LetInLexicalBinding, { at });
     }
 
-    if (!(bindingType & BIND_NONE)) {
+    if (!(bindingType & BindingFlag.TYPE_NONE)) {
       this.declareNameFromIdentifier(at, bindingType);
     }
   }

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

@@ -13,23 +13,10 @@ import { Errors } from "../parse-error";
 import { isIdentifierChar, isIdentifierStart } from "../util/identifier";
 import * as charCodes from "charcodes";
 import {
-  BIND_CLASS,
-  BIND_LEXICAL,
-  BIND_VAR,
-  BIND_FUNCTION,
-  SCOPE_CLASS,
-  SCOPE_FUNCTION,
-  SCOPE_OTHER,
-  SCOPE_SIMPLE_CATCH,
-  SCOPE_STATIC_BLOCK,
-  SCOPE_SUPER,
-  CLASS_ELEMENT_OTHER,
-  CLASS_ELEMENT_INSTANCE_GETTER,
-  CLASS_ELEMENT_INSTANCE_SETTER,
-  CLASS_ELEMENT_STATIC_GETTER,
-  CLASS_ELEMENT_STATIC_SETTER,
+  ScopeFlag,
+  ClassElementType,
   type BindingTypes,
-  BIND_CATCH_PARAM,
+  BindingFlag,
 } from "../util/scopeflags";
 import { ExpressionErrors } from "./util";
 import { PARAM, functionFlags } from "../util/production-parameter";
@@ -932,7 +919,7 @@ export default abstract class StatementParser extends ExpressionParser {
     if (this.isAwaitAllowed() && this.eatContextual(tt._await)) {
       awaitAt = this.state.lastTokStartLoc;
     }
-    this.scope.enter(SCOPE_OTHER);
+    this.scope.enter(ScopeFlag.OTHER);
     this.expect(tt.parenL);
 
     if (this.match(tt.semi)) {
@@ -1091,7 +1078,7 @@ export default abstract class StatementParser extends ExpressionParser {
     const cases: N.SwitchStatement["cases"] = (node.cases = []);
     this.expect(tt.braceL);
     this.state.labels.push(switchLabel);
-    this.scope.enter(SCOPE_OTHER);
+    this.scope.enter(ScopeFlag.OTHER);
 
     // Statements under must be grouped (by label) in SwitchCase
     // nodes. `cur` is used to keep the node that we are currently
@@ -1148,12 +1135,12 @@ export default abstract class StatementParser extends ExpressionParser {
 
     this.scope.enter(
       this.options.annexB && param.type === "Identifier"
-        ? SCOPE_SIMPLE_CATCH
+        ? ScopeFlag.SIMPLE_CATCH
         : 0,
     );
     this.checkLVal(param, {
       in: { type: "CatchClause" },
-      binding: BIND_CATCH_PARAM,
+      binding: BindingFlag.TYPE_CATCH_PARAM,
     });
 
     return param;
@@ -1177,7 +1164,7 @@ export default abstract class StatementParser extends ExpressionParser {
         this.expect(tt.parenR);
       } else {
         clause.param = null;
-        this.scope.enter(SCOPE_OTHER);
+        this.scope.enter(ScopeFlag.OTHER);
       }
 
       // Parse the catch clause's body.
@@ -1344,7 +1331,7 @@ export default abstract class StatementParser extends ExpressionParser {
     }
     this.expect(tt.braceL);
     if (createNewLexicalScope) {
-      this.scope.enter(SCOPE_OTHER);
+      this.scope.enter(ScopeFlag.OTHER);
     }
     this.parseBlockBody(
       node,
@@ -1585,7 +1572,7 @@ export default abstract class StatementParser extends ExpressionParser {
     const id = this.parseBindingAtom();
     this.checkLVal(id, {
       in: { type: "VariableDeclarator" },
-      binding: kind === "var" ? BIND_VAR : BIND_LEXICAL,
+      binding: kind === "var" ? BindingFlag.TYPE_VAR : BindingFlag.TYPE_LEXICAL,
     });
     decl.id = id;
   }
@@ -1629,7 +1616,7 @@ export default abstract class StatementParser extends ExpressionParser {
 
     const oldMaybeInArrowParameters = this.state.maybeInArrowParameters;
     this.state.maybeInArrowParameters = false;
-    this.scope.enter(SCOPE_FUNCTION);
+    this.scope.enter(ScopeFlag.FUNCTION);
     this.prodParam.enter(functionFlags(isAsync, node.generator));
 
     if (!isDeclaration) {
@@ -1690,16 +1677,16 @@ export default abstract class StatementParser extends ExpressionParser {
     if (!node.id) return;
 
     // If it is a regular function declaration in sloppy mode, then it is
-    // subject to Annex B semantics (BIND_FUNCTION). Otherwise, the binding
+    // subject to Annex B semantics (BindingFlag.TYPE_FUNCTION). Otherwise, the binding
     // mode depends on properties of the current scope (see
     // treatFunctionsAsVar).
     this.scope.declareName(
       node.id.name,
       !this.options.annexB || this.state.strict || node.generator || node.async
         ? this.scope.treatFunctionsAsVar
-          ? BIND_VAR
-          : BIND_LEXICAL
-        : BIND_FUNCTION,
+          ? BindingFlag.TYPE_VAR
+          : BindingFlag.TYPE_LEXICAL
+        : BindingFlag.TYPE_FUNCTION,
       node.id.loc.start,
     );
   }
@@ -2114,7 +2101,9 @@ export default abstract class StatementParser extends ExpressionParser {
     >,
   ) {
     // Start a new lexical scope
-    this.scope.enter(SCOPE_CLASS | SCOPE_STATIC_BLOCK | SCOPE_SUPER);
+    this.scope.enter(
+      ScopeFlag.CLASS | ScopeFlag.STATIC_BLOCK | ScopeFlag.SUPER,
+    );
     // Start a new scope with regard to loop labels
     const oldLabels = this.state.labels;
     this.state.labels = [];
@@ -2159,7 +2148,7 @@ export default abstract class StatementParser extends ExpressionParser {
 
     this.classScope.declarePrivateName(
       this.getPrivateNameSV(node.key),
-      CLASS_ELEMENT_OTHER,
+      ClassElementType.OTHER,
       node.key.loc.start,
     );
   }
@@ -2187,7 +2176,7 @@ export default abstract class StatementParser extends ExpressionParser {
     if (isPrivate) {
       this.classScope.declarePrivateName(
         this.getPrivateNameSV(node.key),
-        CLASS_ELEMENT_OTHER,
+        ClassElementType.OTHER,
         node.key.loc.start,
       );
     }
@@ -2236,13 +2225,13 @@ export default abstract class StatementParser extends ExpressionParser {
     const kind =
       node.kind === "get"
         ? node.static
-          ? CLASS_ELEMENT_STATIC_GETTER
-          : CLASS_ELEMENT_INSTANCE_GETTER
+          ? ClassElementType.STATIC_GETTER
+          : ClassElementType.INSTANCE_GETTER
         : node.kind === "set"
         ? node.static
-          ? CLASS_ELEMENT_STATIC_SETTER
-          : CLASS_ELEMENT_INSTANCE_SETTER
-        : CLASS_ELEMENT_OTHER;
+          ? ClassElementType.STATIC_SETTER
+          : ClassElementType.INSTANCE_SETTER
+        : ClassElementType.OTHER;
     this.declareClassPrivateMethodInScope(node, kind);
   }
 
@@ -2298,7 +2287,7 @@ export default abstract class StatementParser extends ExpressionParser {
       N.ClassProperty | N.ClassPrivateProperty | N.ClassAccessorProperty
     >,
   ): void {
-    this.scope.enter(SCOPE_CLASS | SCOPE_SUPER);
+    this.scope.enter(ScopeFlag.CLASS | ScopeFlag.SUPER);
     this.expressionScope.enter(newExpressionScope());
     this.prodParam.enter(PARAM);
     node.value = this.eat(tt.eq) ? this.parseMaybeAssignAllowIn() : null;
@@ -2311,7 +2300,7 @@ export default abstract class StatementParser extends ExpressionParser {
     node: Undone<N.Class>,
     isStatement: boolean,
     optionalId?: boolean | null,
-    bindingType: BindingTypes = BIND_CLASS,
+    bindingType: BindingTypes = BindingFlag.TYPE_CLASS,
   ): void {
     if (tokenIsIdentifier(this.state.type)) {
       node.id = this.parseIdentifier();
@@ -3133,7 +3122,11 @@ export default abstract class StatementParser extends ExpressionParser {
       | N.ImportSpecifier
       | N.ImportDefaultSpecifier
       | N.ImportNamespaceSpecifier,
-  >(specifier: Undone<T>, type: T["type"], bindingType = BIND_LEXICAL) {
+  >(
+    specifier: Undone<T>,
+    type: T["type"],
+    bindingType: BindingTypes = BindingFlag.TYPE_LEXICAL,
+  ) {
     this.checkLVal(specifier.local, {
       in: { type },
       binding: bindingType,

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

@@ -11,7 +11,7 @@ import { lineBreak, skipWhiteSpaceToLineBreak } from "../util/whitespace";
 import { isIdentifierChar } from "../util/identifier";
 import ClassScopeHandler from "../util/class-scope";
 import ExpressionScopeHandler from "../util/expression-scope";
-import { SCOPE_PROGRAM } from "../util/scopeflags";
+import { ScopeFlag } from "../util/scopeflags";
 import ProductionParameterHandler, {
   PARAM_AWAIT,
   PARAM,
@@ -347,7 +347,7 @@ export default abstract class UtilParser extends Tokenizer {
     if (this.inModule) {
       paramFlags |= PARAM_AWAIT;
     }
-    this.scope.enter(SCOPE_PROGRAM);
+    this.scope.enter(ScopeFlag.PROGRAM);
     this.prodParam.enter(paramFlags);
   }