fix(eslint-plugin): [no-empty-interface] disable autofix for declaration merging with class

packages/eslint-plugin/src/rules/no-empty-interface.ts

@@ -1,4 +1,5 @@
 import type { TSESLint } from '@typescript-eslint/utils';
+import { AST_NODE_TYPES } from '@typescript-eslint/utils';
 
 import * as util from '../util';
 
@@ -73,29 +74,39 @@ export default util.createRule<Options, MessageIds>({
                 )}${typeParam} = ${sourceCode.getText(extend[0])}`,
               );
             };
+            const scope = context.getScope();
 
-            // Check if interface is within ambient declaration
-            let useAutoFix = true;
-            if (util.isDefinitionFile(filename)) {
-              const scope = context.getScope();
-              if (scope.type === 'tsModule' && scope.block.declare) {
-                useAutoFix = false;
-              }
-            }
+            const mergedWithClassDeclaration = scope.set
+              .get(node.id.name)
+              ?.defs?.some(
+                def => def.node.type === AST_NODE_TYPES.ClassDeclaration,
+              );
+
+            const isInAmbientDeclaration = !!(
+              util.isDefinitionFile(filename) &&
+              scope.type === 'tsModule' &&
+              scope.block.declare
+            );
+
+            const useAutoFix = !(
+              isInAmbientDeclaration || mergedWithClassDeclaration
+            );
 
             context.report({
               node: node.id,
               messageId: 'noEmptyWithSuper',
               ...(useAutoFix
                 ? { fix }
-                : {
+                : !mergedWithClassDeclaration
+                ? {
                     suggest: [
                       {
                         messageId: 'noEmptyWithSuper',
                         fix,
                       },
                     ],
-                  }),
+                  }
+                : null),
             });
           }
         }

packages/eslint-plugin/tests/rules/no-empty-interface.test.ts

@@ -34,6 +34,18 @@ interface Bar extends Foo {}
       `,
       options: [{ allowSingleExtends: true }],
     },
+    {
+      code: `
+interface Foo {
+  props: string;
+}
+
+interface Bar extends Foo {}
+
+class Bar {}
+      `,
+      options: [{ allowSingleExtends: true }],
+    },
   ],
   invalid: [
     {
@@ -58,6 +70,82 @@ interface Bar extends Foo {}
     },
     {
       code: `
+interface Foo {
+  props: string;
+}
+
+interface Bar extends Foo {}
+
+class Baz {}
+      `,
+      output: `
+interface Foo {
+  props: string;
+}
+
+type Bar = Foo
+
+class Baz {}
+      `,
+      options: [{ allowSingleExtends: false }],
+      errors: [
+        {
+          messageId: 'noEmptyWithSuper',
+          line: 6,
+          column: 11,
+        },
+      ],
+    },
+    {
+      code: `
+interface Foo {
+  props: string;
+}
+
+interface Bar extends Foo {}
+
+class Bar {}
+      `,
+      options: [{ allowSingleExtends: false }],
+      errors: [
+        {
+          messageId: 'noEmptyWithSuper',
+          line: 6,
+          column: 11,
+        },
+      ],
+      output: null,
+    },
+    {
+      code: `
+interface Foo {
+  props: string;
+}
+
+interface Bar extends Foo {}
+
+const bar = class Bar {};
+      `,
+      output: `
+interface Foo {
+  props: string;
+}
+
+type Bar = Foo
+
+const bar = class Bar {};
+      `,
+      options: [{ allowSingleExtends: false }],
+      errors: [
+        {
+          messageId: 'noEmptyWithSuper',
+          line: 6,
+          column: 11,
+        },
+      ],
+    },
+    {
+      code: `
 interface Foo {
   name: string;
 }