better-auth/docs/lib/copy-schema/index.test.ts

import { describe, expect, it } from "vitest";
import { drizzleResolver } from "./adapter/drizzle";
import { prismaResolver } from "./adapter/prisma";
import { copySchema } from "./index";
import type { DBSchema } from "./types";
import { getIndexName } from "./utils";

const schema = {
	modelName: "deviceCode",
	fields: [
		{ fieldName: "id", type: "string", required: true },
		{
			fieldName: "deviceCode",
			type: "string",
			required: true,
			index: true,
		},
		{ fieldName: "userCode", type: "string", required: true, index: true },
		{
			fieldName: "uniqueCode",
			type: "string",
			required: true,
			unique: true,
			index: true,
		},
	],
} satisfies DBSchema;

/**
 * @see https://github.com/better-auth/better-auth/issues/10025
 */
describe("copySchema indexes", () => {
	it("generates portable non-unique SQL indexes", () => {
		const mysql = copySchema(schema, {
			dialect: "mysql",
			mode: "create",
		}).result;

		expect(mysql).toContain("`deviceCode` varchar(191)");
		expect(mysql).toContain("`deviceCode`(191)");
		expect(mysql).toContain("`userCode`(191)");
		expect(mysql).not.toContain("uniqueCode_idx");

		for (const dialect of ["sqlite", "postgresql", "mssql"] as const) {
			const result = copySchema(schema, { dialect, mode: "create" }).result;
			expect(result).toContain("deviceCode_idx");
			expect(result).toContain("userCode_idx");
			expect(result).not.toContain("uniqueCode_idx");
		}
	});

	it("preserves the same index contract in Prisma and Drizzle", () => {
		const prisma = copySchema(schema, {
			dialect: prismaResolver({ provider: "mysql" }),
			mode: "create",
		}).result;
		expect(prisma).toContain("@@index([deviceCode]");
		expect(prisma).not.toContain("@@index([uniqueCode]");

		const drizzle = copySchema(schema, {
			dialect: drizzleResolver({ provider: "mysql" }),
			mode: "create",
		}).result;
		expect(drizzle).toContain('varchar("device_code", { length: 191 })');
		expect(drizzle).toContain(".on(table.deviceCode)");
		expect(drizzle).not.toContain(".on(table.uniqueCode)");
	});

	it("keeps generated index names within the portable byte limit", () => {
		const indexName = getIndexName(
			"deviceAuthorizationCodeWithAnExtremelyLongTableName",
			{
				fieldName: "deviceAuthorizationCodeWithAnExtremelyLongFieldName",
				type: "string",
				index: true,
			},
		);

		expect(new TextEncoder().encode(indexName).byteLength).toBeLessThanOrEqual(
			63,
		);
	});
});