Parser refactoring (#11871)

* refactor: parseMaybeUnary => parseUnary

* refactor: extract shouldExitDescending method

* refactor: add parseUpdate

* refactor: avoid comparing with hardcoded token value

* refactor: add ParseNewOrNewTarget

* refactor: add parseCoverCallAndAsyncArrowHead

* add parseBind

* refactor: polish parseTaggedTemplateExpression interface

* refactor: add parseMember method

* refactor: add parseSuper method

* refactor: add parseAsyncArrowUnaryFunction method

* fix: disallow line break before async binding arrow

* refactor: simplify tt.name logic

* refactor: add parseDo method

* refactor: misc

* refactor: rename parseObjectMember by parsePropertyDefinition

* refactor: unify set/get/async keyword parsing in ObjectMethod

* refactor: misc

* refactor: add parseArrayLike method

* refactor: move fsharp epilogure and prologue inside parseObjectLike

* fixup

* refactor: rename parseFunctionExpression to parseFunctionOrFunctionSent

* refactor: remove redundant logic

* refactor: rename parseClassPropertyName by parseClassElementName

* refactor: avoid unecessary lookahead when parsing tt._export

* fix: export-default-from should support escaped async as export binding

* address review comments

* parseUnary -> parseMaybeUnary

packages/babel-parser/src/plugins/estree.js

@@ -313,14 +313,14 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       isGenerator: boolean,
       isAsync: boolean,
       isPattern: boolean,
-      containsEsc: boolean,
+      isAccessor: boolean,
     ): ?N.ObjectMethod {
       const node: N.EstreeProperty = (super.parseObjectMethod(
         prop,
         isGenerator,
         isAsync,
         isPattern,
-        containsEsc,
+        isAccessor,
       ): any);
 
       if (node) {

packages/babel-parser/src/plugins/flow.js

@@ -2362,8 +2362,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       isGenerator: boolean,
       isAsync: boolean,
       isPattern: boolean,
+      isAccessor: boolean,
       refExpressionErrors: ?ExpressionErrors,
-      containsEsc: boolean,
     ): void {
       if ((prop: $FlowFixMe).variance) {
         this.unexpected((prop: $FlowFixMe).variance.start);
@@ -2373,7 +2373,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       let typeParameters;
 
       // method shorthand
-      if (this.isRelational("<")) {
+      if (this.isRelational("<") && !isAccessor) {
         typeParameters = this.flowParseTypeParameterDeclaration();
         if (!this.match(tt.parenL)) this.unexpected();
       }
@@ -2385,8 +2385,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
         isGenerator,
         isAsync,
         isPattern,
+        isAccessor,
         refExpressionErrors,
-        containsEsc,
       );
 
       // add typeParameters if we found them

packages/babel-parser/src/plugins/typescript/index.js

@@ -1823,13 +1823,14 @@ export default (superClass: Class<Parser>): Class<Parser> =>
               node.typeParameters = typeArguments;
               return this.finishCallExpression(node, state.optionalChainMember);
             } else if (this.match(tt.backQuote)) {
-              return this.parseTaggedTemplateExpression(
+              const result = this.parseTaggedTemplateExpression(
+                base,
                 startPos,
                 startLoc,
-                base,
                 state,
-                typeArguments,
               );
+              result.typeParameters = typeArguments;
+              return result;
             }
           }