typescript-eslint · JoshuaKGoldberg · Mar 3, 2025 · Feb 25, 2025 · Feb 25, 2025 · Feb 25, 2025
diff --git a/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.mdx b/packages/eslint-plugin/docs/rules/explicit-module-boundary-types.mdx
@@ -260,6 +260,20 @@ export const foo: FooType = bar => {};
 </TabItem>
 </Tabs>
 
+### `allowOverloadFunctions`
+
+{/* insert option description */}
+
+Examples of correct code when `allowOverloadFunctions` is set to `true`:
+
+```ts option='{ "allowOverloadFunctions": true }' showPlaygroundButton
+export function test(a: string): string;
+export function test(a: number): number;
+export function test(a: unknown) {
+  return a;
+}
+```
+
 ## When Not To Use It
 
 If your project is not used by downstream consumers that are sensitive to API types, you can disable this rule.

diff --git a/packages/eslint-plugin/src/rules/explicit-module-boundary-types.ts b/packages/eslint-plugin/src/rules/explicit-module-boundary-types.ts
@@ -9,7 +9,12 @@ import type {
   FunctionNode,
 } from '../util/explicitReturnTypeUtils';
 
-import { createRule, isFunction, isStaticMemberAccessOfValue } from '../util';
+import {
+  createRule,
+  hasOverloadSignatures,
+  isFunction,
+  isStaticMemberAccessOfValue,
+} from '../util';
 import {
   ancestorHasReturnType,
   checkFunctionExpressionReturnType,
@@ -25,6 +30,7 @@ export type Options = [
     allowedNames?: string[];
     allowHigherOrderFunctions?: boolean;
     allowTypedFunctionExpressions?: boolean;
+    allowOverloadFunctions?: boolean;
   },
 ];
 export type MessageIds =
@@ -82,6 +88,11 @@ export default createRule<Options, MessageIds>({
               'You must still type the parameters of the function.',
             ].join('\n'),
           },
+          allowOverloadFunctions: {
+            type: 'boolean',
+            description:
+              'Whether to ignore return type annotations on functions with overload signatures.',
+          },
           allowTypedFunctionExpressions: {
             type: 'boolean',
             description:
@@ -97,6 +108,7 @@ export default createRule<Options, MessageIds>({
       allowDirectConstAssertionInArrowFunctions: true,
       allowedNames: [],
       allowHigherOrderFunctions: true,
+      allowOverloadFunctions: false,
       allowTypedFunctionExpressions: true,
     },
   ],
@@ -456,6 +468,14 @@ export default createRule<Options, MessageIds>({
         return;
       }
 
+      if (
+        options.allowOverloadFunctions &&
+        node.parent.type === AST_NODE_TYPES.MethodDefinition &&
+        hasOverloadSignatures(node.parent, context)
+      ) {
+        return;
+      }
+
       checkFunctionExpressionReturnType(
         { node, returns },
         options,
@@ -485,6 +505,13 @@ export default createRule<Options, MessageIds>({
         return;
       }
 
+      if (
+        options.allowOverloadFunctions &&
+        hasOverloadSignatures(node, context)
+      ) {
+        return;
+      }
+
       checkFunctionReturnType(
         { node, returns },
         options,

diff --git a/...ages/eslint-plugin/tests/docs-eslint-output-snapshots/explicit-module-boundary-types.shot b/...ages/eslint-plugin/tests/docs-eslint-output-snapshots/explicit-module-boundary-types.shot
diff --git a/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts b/packages/eslint-plugin/tests/rules/explicit-module-boundary-types.test.ts
@@ -821,6 +821,64 @@ export const a: Foo = {
   f: (x: boolean) => x,
 };
     `,
+    {
+      code: `
+export function test(a: string): string;
+export function test(a: number): number;
+export function test(a: unknown) {
+  return a;
+}
+      `,
+      options: [
+        {
+          allowOverloadFunctions: true,
+        },
+      ],
+    },
+    {
+      code: `
+export default function test(a: string): string;
+export default function test(a: number): number;
+export default function test(a: unknown) {
+  return a;
+}
+      `,
+      options: [
+        {
+          allowOverloadFunctions: true,
+        },
+      ],
+    },
+    {
+      code: `
+export default function (a: string): string;
+export default function (a: number): number;
+export default function (a: unknown) {
+  return a;
+}
+      `,
+      options: [
+        {
+          allowOverloadFunctions: true,
+        },
+      ],
+    },
+    {
+      code: `
+export class Test {
+  test(a: string): string;
+  test(a: number): number;
+  test(a: unknown) {
+    return a;
+  }
+}
+      `,
+      options: [
+        {
+          allowOverloadFunctions: true,
+        },
+      ],
+    },
   ],
   invalid: [
     {
@@ -2077,5 +2135,75 @@ export const foo = {
         },
       ],
     },
+    {
+      code: `
+export function test(a: string): string;
+export function test(a: number): number;
+export function test(a: unknown) {
+  return a;
+}
+      `,
+      errors: [
+        {
+          column: 8,
+          endColumn: 21,
+          line: 4,
+          messageId: 'missingReturnType',
+        },
+      ],
+    },
+    {
+      code: `
+export default function test(a: string): string;
+export default function test(a: number): number;
+export default function test(a: unknown) {
+  return a;
+}
+      `,
+      errors: [
+        {
+          column: 16,
+          endColumn: 29,
+          line: 4,
+          messageId: 'missingReturnType',
+        },
+      ],
+    },
+    {
+      code: `
+export default function (a: string): string;
+export default function (a: number): number;
+export default function (a: unknown) {
+  return a;
+}
+      `,
+      errors: [
+        {
+          column: 16,
+          endColumn: 25,
+          line: 4,
+          messageId: 'missingReturnType',
+        },
+      ],
+    },
+    {
+      code: `
+export class Test {
+  test(a: string): string;
+  test(a: number): number;
+  test(a: unknown) {
+    return a;
+  }
+}
+      `,
+      errors: [
+        {
+          column: 3,
+          endColumn: 7,
+          line: 5,
+          messageId: 'missingReturnType',
+        },
+      ],
+    },
   ],
 });
diff --git a/packages/eslint-plugin/tests/schema-snapshots/explicit-module-boundary-types.shot b/packages/eslint-plugin/tests/schema-snapshots/explicit-module-boundary-types.shot