typescript-eslint · JoshuaKGoldberg · Oct 6, 2025 · Sep 28, 2025 · Sep 28, 2025 · Sep 28, 2025
diff --git a/...st-spec/src/declaration/ClassDeclaration/fixtures/_error_/abstract-constructor/fixture.ts b/...st-spec/src/declaration/ClassDeclaration/fixtures/_error_/abstract-constructor/fixture.ts
@@ -0,0 +1,3 @@
+abstract class Foo  {
+  abstract constructor() { }
+}
diff --git a/...on/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/1-TSESTree-Error.shot b/...on/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/1-TSESTree-Error.shot
diff --git a/...ation/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/2-Babel-Error.shot b/...ation/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/2-Babel-Error.shot
diff --git a/...n/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/3-Alignment-Error.shot b/...n/ClassDeclaration/fixtures/_error_/abstract-constructor/snapshots/3-Alignment-Error.shot
diff --git a/...laration/ClassDeclaration/fixtures/_error_/abstract-getter-with-implementation/fixture.ts b/...laration/ClassDeclaration/fixtures/_error_/abstract-getter-with-implementation/fixture.ts
@@ -0,0 +1,3 @@
+abstract class Foo  {
+  abstract get getter() { }
+}
diff --git a/...tion/fixtures/_error_/abstract-getter-with-implementation/snapshots/1-TSESTree-Error.shot b/...tion/fixtures/_error_/abstract-getter-with-implementation/snapshots/1-TSESTree-Error.shot
diff --git a/...aration/fixtures/_error_/abstract-getter-with-implementation/snapshots/2-Babel-Error.shot b/...aration/fixtures/_error_/abstract-getter-with-implementation/snapshots/2-Babel-Error.shot
diff --git a/...ion/fixtures/_error_/abstract-getter-with-implementation/snapshots/3-Alignment-Error.shot b/...ion/fixtures/_error_/abstract-getter-with-implementation/snapshots/3-Alignment-Error.shot
diff --git a/...laration/ClassDeclaration/fixtures/_error_/abstract-method-with-implementation/fixture.ts b/...laration/ClassDeclaration/fixtures/_error_/abstract-method-with-implementation/fixture.ts
@@ -0,0 +1,3 @@
+abstract class Foo  {
+  abstract method() { }
+}
diff --git a/...tion/fixtures/_error_/abstract-method-with-implementation/snapshots/1-TSESTree-Error.shot b/...tion/fixtures/_error_/abstract-method-with-implementation/snapshots/1-TSESTree-Error.shot
diff --git a/...aration/fixtures/_error_/abstract-method-with-implementation/snapshots/2-Babel-Error.shot b/...aration/fixtures/_error_/abstract-method-with-implementation/snapshots/2-Babel-Error.shot
diff --git a/...ion/fixtures/_error_/abstract-method-with-implementation/snapshots/3-Alignment-Error.shot b/...ion/fixtures/_error_/abstract-method-with-implementation/snapshots/3-Alignment-Error.shot
diff --git a/...laration/ClassDeclaration/fixtures/_error_/abstract-setter-with-implementation/fixture.ts b/...laration/ClassDeclaration/fixtures/_error_/abstract-setter-with-implementation/fixture.ts
@@ -0,0 +1,3 @@
+abstract class Foo  {
+  abstract set setter(v) { }
+}
diff --git a/...tion/fixtures/_error_/abstract-setter-with-implementation/snapshots/1-TSESTree-Error.shot b/...tion/fixtures/_error_/abstract-setter-with-implementation/snapshots/1-TSESTree-Error.shot
diff --git a/...aration/fixtures/_error_/abstract-setter-with-implementation/snapshots/2-Babel-Error.shot b/...aration/fixtures/_error_/abstract-setter-with-implementation/snapshots/2-Babel-Error.shot
diff --git a/...ion/fixtures/_error_/abstract-setter-with-implementation/snapshots/3-Alignment-Error.shot b/...ion/fixtures/_error_/abstract-setter-with-implementation/snapshots/3-Alignment-Error.shot
diff --git a/packages/eslint-plugin/tests/rules/member-ordering.test.ts b/packages/eslint-plugin/tests/rules/member-ordering.test.ts
@@ -4465,7 +4465,7 @@ abstract class Foo {
   B: string;
   public C() {}
   private D() {}
-  abstract E() {}
+  E() {}
 }
       `,
       errors: [
@@ -4478,6 +4478,15 @@ abstract class Foo {
           line: 4,
           messageId: 'incorrectGroupOrder',
         },
+        {
+          column: 3,
+          data: {
+            name: 'E',
+            rank: 'private instance method',
+          },
+          line: 7,
+          messageId: 'incorrectGroupOrder',
+        },
       ],
     },
     {

diff --git a/packages/eslint-plugin/tests/rules/naming-convention/naming-convention.test.ts b/packages/eslint-plugin/tests/rules/naming-convention/naming-convention.test.ts
@@ -632,7 +632,7 @@ ruleTester.run('naming-convention', rule, {
     {
       code: `
         class Ignored {
-          private static abstract some_name() {}
+          private static some_name() {}
           IgnoredDueToModifiers() {}
         }
       `,
@@ -644,7 +644,7 @@ ruleTester.run('naming-convention', rule, {
         },
         {
           format: ['UPPER_CASE'],
-          modifiers: ['abstract', 'static'],
+          modifiers: ['static'],
           selector: 'classMethod',
         },
       ],
@@ -1875,7 +1875,7 @@ ruleTester.run('naming-convention', rule, {
     {
       code: `
         class Ignored {
-          private static abstract some_name() {}
+          private static some_name() {}
           IgnoredDueToModifiers() {}
         }
       `,
@@ -1886,7 +1886,7 @@ ruleTester.run('naming-convention', rule, {
         },
         {
           format: ['snake_case'],
-          modifiers: ['abstract', 'static'],
+          modifiers: ['static'],
           selector: 'classMethod',
         },
       ],
@@ -2118,10 +2118,10 @@ ruleTester.run('naming-convention', rule, {
           }
         }
         abstract class foo {
-          public abstract Bar() {
+          public Bar() {
             return 42;
           }
-          public abstract async async_bar() {
+          public async async_bar() {
             return 42;
           }
         }

diff --git a/packages/eslint-plugin/tests/rules/promise-function-async.test.ts b/packages/eslint-plugin/tests/rules/promise-function-async.test.ts
@@ -156,11 +156,6 @@ function foo(): Promise<string> | boolean {
       code: `
 abstract class Test {
   abstract test1(): Promise<number>;
-
-  // abstract method with body is always an error but it still parses into valid AST
-  abstract test2(): Promise<number> {
-    return Promise.resolve(1);
-  }
 }
       `,
     },

diff --git a/packages/typescript-estree/src/convert.ts b/packages/typescript-estree/src/convert.ts
@@ -14,6 +14,7 @@ import { getDecorators, getModifiers } from './getModifiers';
 import {
   canContainDirective,
   createError,
+  declarationNameToString,
   findNextToken,
   getBinaryExpressionType,
   getContainingFunction,
@@ -1599,6 +1600,18 @@ export class Converter {
       }
       // otherwise, it is a non-type accessor - intentional fallthrough
       case SyntaxKind.MethodDeclaration: {
+        const isAbstract = hasModifier(SyntaxKind.AbstractKeyword, node);
+
+        if (isAbstract && node.body) {
+          this.#throwError(
+            node.name,
+            node.kind === SyntaxKind.GetAccessor ||
+              node.kind === SyntaxKind.SetAccessor
+              ? 'An abstract accessor cannot have an implementation.'
+              : `Method '${declarationNameToString(node.name, this.ast)}' cannot have an implementation because it is marked abstract.`,
+          );
+        }
+
         const method = this.createNode<
           TSESTree.FunctionExpression | TSESTree.TSEmptyBodyFunctionExpression
         >(node, {
@@ -1654,10 +1667,7 @@ export class Converter {
           /**
            * TypeScript class methods can be defined as "abstract"
            */
-          const methodDefinitionType = hasModifier(
-            SyntaxKind.AbstractKeyword,
-            node,
-          )
+          const methodDefinitionType = isAbstract
             ? AST_NODE_TYPES.TSAbstractMethodDefinition
             : AST_NODE_TYPES.MethodDefinition;
 

diff --git a/packages/typescript-estree/src/node-utils.ts b/packages/typescript-estree/src/node-utils.ts
@@ -919,3 +919,12 @@ export function getNamespaceModifiers(
   }
   return modifiers;
 }
+
+// `ts.declarationNameToString`
+export function declarationNameToString(
+  name: ts.Node,
+  ast: ts.SourceFile,
+): string {
+  const text = ast.text.slice(name.pos, name.end).trimStart();
+  return text || '(Missing)';
+}