fix: access control indexing type (#8155)

YevheniiKotyrlo · himself65 · himself65 · commit 5d7dd9ea22ad · 2026-03-03T18:28:54.000+09:00
Co-authored-by: Alex Yang &lt;himself65@outlook.com&gt;
diff --git a/packages/better-auth/src/plugins/access/types.ts b/packages/better-auth/src/plugins/access/types.ts
@@ -1,6 +1,8 @@
 import type { LiteralString } from "@better-auth/core";
 import type { AuthorizeResponse, createAccessControl } from "./access";
 
+export type ArrayElement<T> = T extends readonly (infer E)[] ? E : never;
+
 export type SubArray<T extends unknown[] | readonly unknown[] | any[]> =
 	| T[number][]
 	| ReadonlyArray<T[number]>;
diff --git a/packages/better-auth/src/plugins/admin/client.ts b/packages/better-auth/src/plugins/admin/client.ts
@@ -1,5 +1,5 @@
 import type { BetterAuthClientPlugin } from "@better-auth/core";
-import type { AccessControl, Role } from "../access";
+import type { AccessControl, ArrayElement, Role } from "../access";
 import type { defaultStatements } from "./access";
 import { adminAc, userAc } from "./access";
 import type { admin } from "./admin";
@@ -26,7 +26,7 @@ export const adminClient = <O extends AdminClientOptions>(
 	type PermissionType = {
 		[key in keyof Statements]?: Array<
 			Statements[key] extends readonly unknown[]
-				? Statements[key][number]
+				? ArrayElement<Statements[key]>
 				: never
 		>;
 	};
diff --git a/packages/better-auth/src/plugins/admin/routes.ts b/packages/better-auth/src/plugins/admin/routes.ts
@@ -15,7 +15,7 @@ import {
 } from "../../cookies";
 import { parseSessionOutput, parseUserOutput } from "../../db/schema";
 import { getDate } from "../../utils/date";
-import type { AccessControl } from "../access";
+import type { AccessControl, ArrayElement } from "../access";
 import type { defaultStatements } from "./access";
 import { ADMIN_ERROR_CODES } from "./error-codes";
 import { hasPermission } from "./has-permission";
@@ -1603,7 +1603,7 @@ export const userHasPermission = <O extends AdminOptions>(opts: O) => {
 	type PermissionType = {
 		[key in keyof Statements]?: Array<
 			Statements[key] extends readonly unknown[]
-				? Statements[key][number]
+				? ArrayElement<Statements[key]>
 				: never
 		>;
 	};
diff --git a/packages/better-auth/src/plugins/organization/client.ts b/packages/better-auth/src/plugins/organization/client.ts
@@ -11,7 +11,7 @@ import type {
 } from "../../plugins/organization/schema";
 import type { BetterAuthOptions, BetterAuthPlugin } from "../../types";
 import type { Prettify } from "../../types/helper";
-import type { AccessControl, Role } from "../access";
+import type { AccessControl, ArrayElement, Role } from "../access";
 import type { defaultStatements } from "./access";
 import { adminAc, defaultRoles, memberAc, ownerAc } from "./access";
 import { ORGANIZATION_ERROR_CODES } from "./error-codes";
@@ -95,7 +95,7 @@ export const organizationClient = <CO extends OrganizationClientOptions>(
 	type PermissionType = {
 		[key in keyof Statements]?: Array<
 			Statements[key] extends readonly unknown[]
-				? Statements[key][number]
+				? ArrayElement<Statements[key]>
 				: never
 		>;
 	};
diff --git a/packages/better-auth/src/plugins/organization/organization.ts b/packages/better-auth/src/plugins/organization/organization.ts
@@ -5,7 +5,7 @@ import { APIError } from "@better-auth/core/error";
 import * as z from "zod";
 import { getSessionFromCtx } from "../../api";
 import { shimContext } from "../../utils/shim";
-import type { AccessControl } from "../access";
+import type { AccessControl, ArrayElement } from "../access";
 import type { defaultStatements } from "./access";
 import { defaultRoles } from "./access";
 import { getOrgAdapter } from "./adapter";
@@ -183,7 +183,7 @@ const createHasPermission = <O extends OrganizationOptions>(options: O) => {
 	type PermissionType = {
 		[key in keyof Statements]?: Array<
 			Statements[key] extends readonly unknown[]
-				? Statements[key][number]
+				? ArrayElement<Statements[key]>
 				: never
 		>;
 	};
