feat(typescript-estree): support private fields in-in syntax

packages/ast-spec/src/expression/AssignmentExpression/spec.ts

@@ -1,7 +1,8 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { BinaryExpressionBase } from '../../base/BinaryExpressionBase';
+import type { BaseNode } from '../../base/BaseNode';
+import type { Expression } from '../../unions/Expression';
 
-export interface AssignmentExpression extends BinaryExpressionBase {
+export interface AssignmentExpression extends BaseNode {
   type: AST_NODE_TYPES.AssignmentExpression;
   operator:
     | '-='
@@ -20,4 +21,6 @@ export interface AssignmentExpression extends BinaryExpressionBase {
     | '>>>='
     | '|='
     | '||=';
+  left: Expression;
+  right: Expression;
 }

packages/ast-spec/src/expression/BinaryExpression/spec.ts

@@ -1,6 +1,11 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { BinaryExpressionBase } from '../../base/BinaryExpressionBase';
+import type { BaseNode } from '../../base/BaseNode';
+import type { PrivateIdentifier } from '../../special/PrivateIdentifier/spec';
+import type { Expression } from '../../unions/Expression';
 
-export interface BinaryExpression extends BinaryExpressionBase {
+export interface BinaryExpression extends BaseNode {
   type: AST_NODE_TYPES.BinaryExpression;
+  operator: string;
+  left: Expression | PrivateIdentifier;
+  right: Expression;
 }

packages/ast-spec/src/expression/LogicalExpression/spec.ts

@@ -1,7 +1,10 @@
 import type { AST_NODE_TYPES } from '../../ast-node-types';
-import type { BinaryExpressionBase } from '../../base/BinaryExpressionBase';
+import type { BaseNode } from '../../base/BaseNode';
+import type { Expression } from '../../unions/Expression';
 
-export interface LogicalExpression extends BinaryExpressionBase {
+export interface LogicalExpression extends BaseNode {
   type: AST_NODE_TYPES.LogicalExpression;
   operator: '??' | '&&' | '||';
+  left: Expression;
+  right: Expression;
 }

packages/eslint-plugin/src/rules/no-base-to-string.ts

@@ -166,7 +166,10 @@ export default util.createRule<Options, MessageIds>({
 
         if (util.getTypeName(typeChecker, leftType) === 'string') {
           checkExpression(node.right, rightType);
-        } else if (util.getTypeName(typeChecker, rightType) === 'string') {
+        } else if (
+          util.getTypeName(typeChecker, rightType) === 'string' &&
+          node.left.type !== AST_NODE_TYPES.PrivateIdentifier
+        ) {
           checkExpression(node.left, leftType);
         }
       },

packages/eslint-plugin/src/rules/no-confusing-non-null-assertion.ts

@@ -38,7 +38,7 @@ export default util.createRule({
         node: TSESTree.BinaryExpression | TSESTree.AssignmentExpression,
       ): void {
         function isLeftHandPrimaryExpression(
-          node: TSESTree.Expression,
+          node: TSESTree.Expression | TSESTree.PrivateIdentifier,
         ): boolean {
           return node.type === AST_NODE_TYPES.TSNonNullExpression;
         }

packages/eslint-plugin/src/rules/no-unnecessary-boolean-literal-compare.ts

@@ -21,7 +21,7 @@ type Options = [
 ];
 
 interface BooleanComparison {
-  expression: TSESTree.Expression;
+  expression: TSESTree.Expression | TSESTree.PrivateIdentifier;
   literalBooleanInComparison: boolean;
   forTruthy: boolean;
   negated: boolean;

packages/eslint-plugin/src/rules/prefer-for-of.ts

@@ -33,7 +33,10 @@ export default util.createRule({
       );
     }
 
-    function isLiteral(node: TSESTree.Expression, value: number): boolean {
+    function isLiteral(
+      node: TSESTree.Expression | TSESTree.PrivateIdentifier,
+      value: number,
+    ): boolean {
       return node.type === AST_NODE_TYPES.Literal && node.value === value;
     }
 

packages/eslint-plugin/src/rules/prefer-string-starts-ends-with.ts

@@ -286,7 +286,9 @@ export default createRule({
       return { isEndsWith, isStartsWith, text };
     }
 
-    function getLeftNode(node: TSESTree.Expression): TSESTree.MemberExpression {
+    function getLeftNode(
+      node: TSESTree.Expression | TSESTree.PrivateIdentifier,
+    ): TSESTree.MemberExpression {
       if (node.type === AST_NODE_TYPES.ChainExpression) {
         return getLeftNode(node.expression);
       }

packages/eslint-plugin/src/rules/restrict-plus-operands.ts

@@ -93,7 +93,9 @@ export default util.createRule<Options, MessageIds>({
      * Helper function to get base type of node
      * @param node the node to be evaluated.
      */
-    function getNodeType(node: TSESTree.Expression): BaseLiteral {
+    function getNodeType(
+      node: TSESTree.Expression | TSESTree.PrivateIdentifier,
+    ): BaseLiteral {
       const tsNode = service.esTreeNodeToTSNodeMap.get(node);
       const type = util.getConstrainedTypeAtLocation(typeChecker, tsNode);
 

packages/shared-fixtures/fixtures/typescript/basics/private-fields-in-in.src.ts

@@ -0,0 +1,6 @@
+class Foo {
+  #prop1;
+  method(arg) {
+    return #prop1 in arg;
+  }
+}

packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap

@@ -2072,6 +2072,8 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/parenthesized-use-strict.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/private-fields-in-in.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/readonly-arrays.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/readonly-tuples.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;