Update: support class fields (refs eslint/eslint#14343) (#69)

* Update: support class fields (refs eslint/eslint#14343)

* upgrade eslint-visitor-keys

* update espree

* make function-scope for class field initializers

* Update package.json

* Update package.json

* Update tests/class-fields.js

* Update tests/class-fields.js

Co-authored-by: Brandon Mills <btmills@users.noreply.github.com>

* Remove trailing whitespace to fix lint failure

* introduce class-field-initializer scope

* fix typo

* fix variableScope

Co-authored-by: Nicholas C. Zakas <nicholas@nczconsulting.com>
Co-authored-by: Brandon Mills <btmills@users.noreply.github.com>

Author: 3 people

lib/referencer.js

@@ -434,6 +434,12 @@ class Referencer extends esrecurse.Visitor {
         this.currentScope().__referencing(node);
     }
 
+    // eslint-disable-next-line class-methods-use-this
+    PrivateIdentifier() {
+
+        // Do nothing.
+    }
+
     UpdateExpression(node) {
         if (PatternVisitor.isPattern(node.argument)) {
             this.currentScope().__referencing(node.argument, Reference.RW, null);
@@ -453,6 +459,19 @@ class Referencer extends esrecurse.Visitor {
         this.visitProperty(node);
     }
 
+    PropertyDefinition(node) {
+        const { computed, key, value } = node;
+
+        if (computed) {
+            this.visit(key);
+        }
+        if (value) {
+            this.scopeManager.__nestClassFieldInitializerScope(value);
+            this.visit(value);
+            this.close(value);
+        }
+    }
+
     MethodDefinition(node) {
         this.visitProperty(node);
     }

lib/scope-manager.js

@@ -25,20 +25,21 @@
 
 /* eslint-disable no-underscore-dangle */
 
-const Scope = require("./scope");
+const {
+    BlockScope,
+    CatchScope,
+    ClassFieldInitializerScope,
+    ClassScope,
+    ForScope,
+    FunctionExpressionNameScope,
+    FunctionScope,
+    GlobalScope,
+    ModuleScope,
+    SwitchScope,
+    WithScope
+} = require("./scope");
 const assert = require("assert");
 
-const GlobalScope = Scope.GlobalScope;
-const CatchScope = Scope.CatchScope;
-const WithScope = Scope.WithScope;
-const ModuleScope = Scope.ModuleScope;
-const ClassScope = Scope.ClassScope;
-const SwitchScope = Scope.SwitchScope;
-const FunctionScope = Scope.FunctionScope;
-const ForScope = Scope.ForScope;
-const FunctionExpressionNameScope = Scope.FunctionExpressionNameScope;
-const BlockScope = Scope.BlockScope;
-
 /**
  * @class ScopeManager
  */
@@ -225,6 +226,10 @@ class ScopeManager {
         return this.__nestScope(new ClassScope(this, this.__currentScope, node));
     }
 
+    __nestClassFieldInitializerScope(node) {
+        return this.__nestScope(new ClassFieldInitializerScope(this, this.__currentScope, node));
+    }
+
     __nestSwitchScope(node) {
         return this.__nestScope(new SwitchScope(this, this.__currentScope, node));
     }

lib/scope.js

@@ -224,7 +224,7 @@ class Scope {
          * @member {Scope} Scope#variableScope
          */
         this.variableScope =
-            (this.type === "global" || this.type === "function" || this.type === "module") ? this : upperScope.variableScope;
+            (this.type === "global" || this.type === "function" || this.type === "module" || this.type === "class-field-initializer") ? this : upperScope.variableScope;
 
         /**
          * Whether this scope is created by a FunctionExpression.
@@ -731,6 +731,12 @@ class ClassScope extends Scope {
     }
 }
 
+class ClassFieldInitializerScope extends Scope {
+    constructor(scopeManager, upperScope, block) {
+        super(scopeManager, "class-field-initializer", upperScope, block, true);
+    }
+}
+
 module.exports = {
     Scope,
     GlobalScope,
@@ -742,7 +748,8 @@ module.exports = {
     SwitchScope,
     FunctionScope,
     ForScope,
-    ClassScope
+    ClassScope,
+    ClassFieldInitializerScope
 };
 
 /* vim: set sw=4 ts=4 et tw=80 : */

package.json

@@ -37,8 +37,8 @@
     "eslint-config-eslint": "^5.0.1",
     "eslint-plugin-node": "^9.1.0",
     "eslint-release": "^1.0.0",
-    "eslint-visitor-keys": "^1.2.0",
-    "espree": "^7.1.0",
+    "eslint-visitor-keys": "^3.0.0",
+    "espree": "^8.0.0",
     "istanbul": "^0.4.5",
     "mocha": "^6.1.4",
     "npm-license": "^0.3.3",