fix: improve additional fields inference ts server performance

packages/better-auth/src/api/routes/sign-up.ts

@@ -8,7 +8,6 @@ import type {
 	BetterAuthOptions,
 	User,
 } from "../../types";
-import type { toZod } from "../../types/to-zod";
 import { parseUserInput } from "../../db/schema";
 import { BASE_ERROR_CODES } from "../../error/codes";
 import { isDevelopment } from "../../utils/env";
@@ -18,13 +17,15 @@ export const signUpEmail = <O extends BetterAuthOptions>() =>
 		"/sign-up/email",
 		{
 			method: "POST",
-			body: z.record(z.string(), z.any()) as unknown as ZodObject<{
-				name: ZodString;
-				email: ZodString;
-				password: ZodString;
-			}> &
-				toZod<AdditionalUserFieldsInput<O>>,
+			body: z.record(z.string(), z.any()),
 			metadata: {
+				$Infer: {
+					body: {} as {
+						name: string;
+						email: string;
+						password: string;
+					} & AdditionalUserFieldsInput<O>,
+				},
 				openapi: {
 					description: "Sign up a user using email and password",
 					requestBody: {

packages/better-auth/src/api/routes/update-user.ts

@@ -1,11 +1,10 @@
-import { z, ZodNull, ZodObject, ZodOptional, ZodString } from "zod";
+import { z } from "zod";
 import { createAuthEndpoint } from "../call";
 
 import { deleteSessionCookie, setSessionCookie } from "../../cookies";
 import { getSessionFromCtx, sessionMiddleware } from "./session";
 import { APIError } from "better-call";
 import { createEmailVerificationToken } from "./email-verification";
-import type { toZod } from "../../types/to-zod";
 import type { AdditionalUserFieldsInput, BetterAuthOptions } from "../../types";
 import { parseUserInput } from "../../db/schema";
 import { generateRandomString } from "../../crypto";
@@ -17,15 +16,15 @@ export const updateUser = <O extends BetterAuthOptions>() =>
 		"/update-user",
 		{
 			method: "POST",
-			body: z.record(z.string(), z.any()) as unknown as toZod<
-				AdditionalUserFieldsInput<O>
-			> &
-				ZodObject<{
-					name: ZodOptional<ZodString>;
-					image: ZodOptional<ZodString | ZodNull>;
-				}>,
+			body: z.record(z.string(), z.any()),
 			use: [sessionMiddleware],
 			metadata: {
+				$Infer: {
+					body: {} as AdditionalUserFieldsInput<O> & {
+						name?: string;
+						image?: string | null;
+					},
+				},
 				openapi: {
 					description: "Update the current user",
 					requestBody: {

packages/better-auth/src/db/field.ts

@@ -153,7 +153,7 @@ export type InferFieldsInput<Field> = Field extends Record<
 						? never
 						: key]: InferFieldInput<Field[key]>;
 		} & {
-			[key in Key as Field[key]["input"] extends false ? never : key]:
+			[key in Key as Field[key]["input"] extends false ? never : key]?:
 				| InferFieldInput<Field[key]>
 				| undefined
 				| null;

packages/better-auth/src/types/to-zod.ts

@@ -1,46 +0,0 @@
-//https://github.com/colinhacks/tozod/blob/master/src/index.ts
-
-import * as z from "zod";
-
-type isAny<T> = [any extends T ? "true" : "false"] extends ["true"]
-	? true
-	: false;
-type nonoptional<T> = T extends undefined ? never : T;
-type nonnullable<T> = T extends null ? never : T;
-type equals<X, Y> = [X] extends [Y] ? ([Y] extends [X] ? true : false) : false;
-
-export type toZod<T> = {
-	any: never;
-	optional: z.ZodUnion<[toZod<nonoptional<T>>, z.ZodUndefined]>;
-	nullable: z.ZodUnion<[toZod<nonnullable<T>>, z.ZodNull]>;
-	array: T extends Array<infer U> ? z.ZodArray<toZod<U>> : never;
-	string: z.ZodString;
-	bigint: z.ZodBigInt;
-	number: z.ZodNumber;
-	boolean: z.ZodBoolean;
-	date: z.ZodDate;
-	object: z.ZodObject<{ [k in keyof T]: toZod<T[k]> }>;
-	rest: never;
-}[zodKey<T>];
-
-type zodKey<T> = isAny<T> extends true
-	? "any"
-	: equals<T, boolean> extends true //[T] extends [booleanUtil.Type]
-		? "boolean"
-		: [undefined] extends [T]
-			? "optional"
-			: [null] extends [T]
-				? "nullable"
-				: T extends any[]
-					? "array"
-					: equals<T, string> extends true
-						? "string"
-						: equals<T, bigint> extends true //[T] extends [bigintUtil.Type]
-							? "bigint"
-							: equals<T, number> extends true //[T] extends [numberUtil.Type]
-								? "number"
-								: equals<T, Date> extends true //[T] extends [dateUtil.Type]
-									? "date"
-									: T extends { [k: string]: any } //[T] extends [structUtil.Type]
-										? "object"
-										: "rest";