From 52ebbfaab678a0453adcf0570141dde7c38840ad Mon Sep 17 00:00:00 2001
From: yeonjuan <yeonjuan93@naver.com>
Date: Sun, 29 Oct 2023 19:35:26 +0900
Subject: [PATCH 1/2] fix(eslint-plugin): [no-unused-vars] handle logical
 assignment

---
 .../src/util/collectUnusedVariables.ts        | 12 ++++++++
 .../no-unused-vars/no-unused-vars.test.ts     | 30 +++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/packages/eslint-plugin/src/util/collectUnusedVariables.ts b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
index 8ec63de10dc6..fb013abbedf2 100644
--- a/packages/eslint-plugin/src/util/collectUnusedVariables.ts
+++ b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
@@ -439,6 +439,17 @@ function isExported(variable: TSESLint.Scope.Variable): boolean {
   });
 }
 
+const LOGICAL_ASSIGNMENT_OPERATORS = new Set(['&&=', '||=', '??=']);
+
+/**
+ * Checks whether the given operator is a logical assignment operator or not.
+ * @param operator The operator
+ * @returns True if the operator is a logical assignment operator.
+ */
+function isLogicalAssignmentOperator(operator: string): boolean {
+  return LOGICAL_ASSIGNMENT_OPERATORS.has(operator);
+}
+
 /**
  * Determines if the variable is used.
  * @param variable The variable to check.
@@ -701,6 +712,7 @@ function isUsedVariable(variable: TSESLint.Scope.Variable): boolean {
       ref.isRead() && // in RHS of an assignment for itself. e.g. `a = a + 1`
       // self update. e.g. `a += 1`, `a++`
       ((parent.type === AST_NODE_TYPES.AssignmentExpression &&
+        !isLogicalAssignmentOperator(parent.operator) &&
         grandparent.type === AST_NODE_TYPES.ExpressionStatement &&
         parent.left === id) ||
         (parent.type === AST_NODE_TYPES.UpdateExpression &&
diff --git a/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts b/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
index 636e2fe8d2c1..baed3954060c 100644
--- a/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unused-vars/no-unused-vars.test.ts
@@ -1099,6 +1099,18 @@ interface Foo {
   bar: string;
 }
     `,
+    `
+let foo = 1;
+foo ??= 2;
+    `,
+    `
+let foo = 1;
+foo &&= 2;
+    `,
+    `
+let foo = 1;
+foo ||= 2;
+    `,
   ],
 
   invalid: [
@@ -1844,5 +1856,23 @@ const Foo = 'bar';
         },
       ],
     },
+    {
+      code: `
+let foo = 1;
+foo += 1;
+      `,
+      errors: [
+        {
+          messageId: 'unusedVar',
+          line: 3,
+          column: 1,
+          data: {
+            varName: 'foo',
+            action: 'assigned a value',
+            additional: '',
+          },
+        },
+      ],
+    },
   ],
 });

From fcb510a88b510f715997e7c8a84540ac099935f5 Mon Sep 17 00:00:00 2001
From: yeonjuan <yeonjuan93@naver.com>
Date: Mon, 30 Oct 2023 21:57:22 +0900
Subject: [PATCH 2/2] refactor

---
 .../eslint-plugin/src/util/collectUnusedVariables.ts  | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/packages/eslint-plugin/src/util/collectUnusedVariables.ts b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
index fb013abbedf2..518a696911b7 100644
--- a/packages/eslint-plugin/src/util/collectUnusedVariables.ts
+++ b/packages/eslint-plugin/src/util/collectUnusedVariables.ts
@@ -441,15 +441,6 @@ function isExported(variable: TSESLint.Scope.Variable): boolean {
 
 const LOGICAL_ASSIGNMENT_OPERATORS = new Set(['&&=', '||=', '??=']);
 
-/**
- * Checks whether the given operator is a logical assignment operator or not.
- * @param operator The operator
- * @returns True if the operator is a logical assignment operator.
- */
-function isLogicalAssignmentOperator(operator: string): boolean {
-  return LOGICAL_ASSIGNMENT_OPERATORS.has(operator);
-}
-
 /**
  * Determines if the variable is used.
  * @param variable The variable to check.
@@ -712,7 +703,7 @@ function isUsedVariable(variable: TSESLint.Scope.Variable): boolean {
       ref.isRead() && // in RHS of an assignment for itself. e.g. `a = a + 1`
       // self update. e.g. `a += 1`, `a++`
       ((parent.type === AST_NODE_TYPES.AssignmentExpression &&
-        !isLogicalAssignmentOperator(parent.operator) &&
+        !LOGICAL_ASSIGNMENT_OPERATORS.has(parent.operator) &&
         grandparent.type === AST_NODE_TYPES.ExpressionStatement &&
         parent.left === id) ||
         (parent.type === AST_NODE_TYPES.UpdateExpression &&