Implement class features in estree (#12370)

Co-authored-by: Kai Cataldo <kai@kaicataldo.com>

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

@@ -194,6 +194,33 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
     }
 
+    parseMaybePrivateName(...args: [boolean]): any {
+      const node = super.parseMaybePrivateName(...args);
+      if (node.type === "PrivateName") {
+        return this.convertPrivateNameToPrivateIdentifier(node);
+      }
+      return node;
+    }
+
+    convertPrivateNameToPrivateIdentifier(
+      node: N.PrivateName,
+    ): N.EstreePrivateIdentifier {
+      const name = super.getPrivateNameSV(node);
+      node = (node: any);
+      delete node.id;
+      node.name = name;
+      node.type = "PrivateIdentifier";
+      return node;
+    }
+
+    isPrivateName(node: N.Node): boolean {
+      return node.type === "PrivateIdentifier";
+    }
+
+    getPrivateNameSV(node: N.Node): string {
+      return node.name;
+    }
+
     parseLiteral<T: N.Literal>(
       value: any,
       type: /*T["kind"]*/ string,
@@ -240,11 +267,27 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       delete funcNode.kind;
       // $FlowIgnore
       node.value = funcNode;
-
-      type = type === "ClassMethod" ? "MethodDefinition" : type;
+      if (type === "ClassPrivateMethod") {
+        // $FlowIgnore
+        node.computed = false;
+      }
+      type = "MethodDefinition";
       return this.finishNode(node, type);
     }
 
+    parseClassProperty(...args: [N.ClassProperty]): any {
+      const propertyNode = (super.parseClassProperty(...args): any);
+      propertyNode.type = "PropertyDefinition";
+      return (propertyNode: N.EstreePropertyDefinition);
+    }
+
+    parseClassPrivateProperty(...args: [N.ClassPrivateProperty]): any {
+      const propertyNode = (super.parseClassPrivateProperty(...args): any);
+      propertyNode.type = "PropertyDefinition";
+      propertyNode.computed = false;
+      return (propertyNode: N.EstreePropertyDefinition);
+    }
+
     parseObjectMethod(
       prop: N.ObjectMethod,
       isGenerator: boolean,

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

@@ -2181,7 +2181,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       if (member.declare) {
         if (
           member.type !== "ClassProperty" &&
-          member.type !== "ClassPrivateProperty"
+          member.type !== "ClassPrivateProperty" &&
+          member.type !== "PropertyDefinition" // Used by estree plugin
         ) {
           this.raise(pos, FlowErrors.DeclareClassElement);
         } else if (member.value) {