typescript-eslint · JoshuaKGoldberg · Nov 10, 2024 · Nov 3, 2024 · Nov 10, 2024
diff --git a/packages/eslint-plugin/tests/eslint-rules/prefer-const.test.ts b/packages/eslint-plugin/tests/eslint-rules/prefer-const.test.ts
@@ -21,5 +21,17 @@ let x: number | undefined = 1;
 let x: number | undefined = 1;
 (x as number) += 1;
     `,
+    `
+let x: number | undefined = 1;
+x!++;
+    `,
+    `
+let x: number | undefined = 1;
+(<number>x)++;
+    `,
+    `
+let x: number | undefined = 1;
+(x as number)++;
+    `,
   ],
 });
diff --git a/packages/scope-manager/src/referencer/Referencer.ts b/packages/scope-manager/src/referencer/Referencer.ts
@@ -325,17 +325,7 @@ class Referencer extends Visitor {
   }
 
   protected AssignmentExpression(node: TSESTree.AssignmentExpression): void {
-    let left = node.left;
-    switch (left.type) {
-      case AST_NODE_TYPES.TSAsExpression:
-      case AST_NODE_TYPES.TSTypeAssertion:
-        // explicitly visit the type annotation
-        this.visitType(left.typeAnnotation);
-      // intentional fallthrough
-      case AST_NODE_TYPES.TSNonNullExpression:
-        // unwrap the expression
-        left = left.expression;
-    }
+    const left = this.visitExpressionTarget(node.left);
 
     if (PatternVisitor.isPattern(left)) {
       if (node.operator === '=') {
@@ -752,8 +742,10 @@ class Referencer extends Visitor {
   }
 
   protected UpdateExpression(node: TSESTree.UpdateExpression): void {
-    if (PatternVisitor.isPattern(node.argument)) {
-      this.visitPattern(node.argument, pattern => {
+    const argument = this.visitExpressionTarget(node.argument);
+
+    if (PatternVisitor.isPattern(argument)) {
+      this.visitPattern(argument, pattern => {
         this.currentScope().referenceValue(
           pattern,
           ReferenceFlag.ReadWrite,
@@ -811,6 +803,21 @@ class Referencer extends Visitor {
 
     this.close(node);
   }
+
+  private visitExpressionTarget(left: TSESTree.Node) {
+    switch (left.type) {
+      case AST_NODE_TYPES.TSAsExpression:
+      case AST_NODE_TYPES.TSTypeAssertion:
+        // explicitly visit the type annotation
+        this.visitType(left.typeAnnotation);
+      // intentional fallthrough
+      case AST_NODE_TYPES.TSNonNullExpression:
+        // unwrap the expression
+        left = left.expression;
+    }
+
+    return left;
+  }
 }
 
 export { Referencer, type ReferencerOptions };
diff --git a/packages/scope-manager/tests/fixtures/type-assertion/increment/angle-bracket-increment.ts b/packages/scope-manager/tests/fixtures/type-assertion/increment/angle-bracket-increment.ts
@@ -0,0 +1,2 @@
+let x: number | undefined = 1;
+(<number>x)++;
diff --git a/...ges/scope-manager/tests/fixtures/type-assertion/increment/angle-bracket-increment.ts.shot b/...ges/scope-manager/tests/fixtures/type-assertion/increment/angle-bracket-increment.ts.shot
diff --git a/packages/scope-manager/tests/fixtures/type-assertion/increment/as-increment.ts b/packages/scope-manager/tests/fixtures/type-assertion/increment/as-increment.ts
@@ -0,0 +1,2 @@
+let x: number | undefined = 1;
+(x as number)++;
diff --git a/packages/scope-manager/tests/fixtures/type-assertion/increment/as-increment.ts.shot b/packages/scope-manager/tests/fixtures/type-assertion/increment/as-increment.ts.shot
diff --git a/packages/scope-manager/tests/fixtures/type-assertion/increment/non-null-increment.ts b/packages/scope-manager/tests/fixtures/type-assertion/increment/non-null-increment.ts
@@ -0,0 +1,2 @@
+let x: number | undefined = 1;
+x!++;
diff --git a/packages/scope-manager/tests/fixtures/type-assertion/increment/non-null-increment.ts.shot b/packages/scope-manager/tests/fixtures/type-assertion/increment/non-null-increment.ts.shot
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		let x: number \| undefined = 1;
		(x as number)++;