fix(adapter-sveltekit): properly handle SvelteKit base path dynamically via $app/paths

Author: jacksonkasi1

packages/adapter-sveltekit/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tablecraft/adapter-sveltekit",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "SvelteKit adapter for TableCraft",
   "type": "module",
   "main": "dist/index.js",

packages/adapter-sveltekit/src/ambient.d.ts

@@ -0,0 +1,3 @@
+declare module '$app/paths' {
+  export const base: string;
+}

packages/adapter-sveltekit/src/index.ts

@@ -1,6 +1,9 @@
 // ** import types
 import type { Handle, RequestEvent, RequestHandler } from '@sveltejs/kit';
 
+// ** import core packages
+import { base } from '$app/paths';
+
 // ** import apis
 import {
   createEngines,
@@ -202,12 +205,15 @@ async function hasTableAccess(
  * @returns The remaining path segment (e.g., 'table/_meta') or null if it doesn't match the prefix
  */
 function stripPrefix(pathname: string, prefix: string): string | null {
-  // Note: Since this is an adapter library, we cannot easily import $app/paths directly
-  // without complicating the build. SvelteKit passes the full URL including base to hooks,
-  // so developers using base paths may need to manually configure the prefix 
-  // (e.g. prefix: '/base/api/data').
+  let cleanPathname = pathname;
+  if (base && cleanPathname.startsWith(base)) {
+    const nextChar = cleanPathname[base.length];
+    if (nextChar === undefined || nextChar === '/') {
+      cleanPathname = cleanPathname.slice(base.length);
+    }
+  }
 
-  const normalizedPath = pathname.replace(/\/+$/g, '') || '/';
+  const normalizedPath = cleanPathname.replace(/\/+$/g, '') || '/';
 
   if (normalizedPath === prefix) {
     return null;

packages/adapter-sveltekit/test/index.test.ts

@@ -1,20 +1,33 @@
 // ** import core packages
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 
-const createEngines = vi.fn();
-const createTableEngine = vi.fn();
-const parseRequest = vi.fn();
-const defaultCheckAccess = vi.fn();
-const getExportMeta = vi.fn();
-
-class MockTableCraftError extends Error {
-  statusCode: number;
-
-  constructor(message: string, statusCode = 500) {
-    super(message);
-    this.statusCode = statusCode;
+const {
+  createEngines,
+  createTableEngine,
+  parseRequest,
+  defaultCheckAccess,
+  getExportMeta,
+  MockTableCraftError,
+  mockState
+} = vi.hoisted(() => {
+  class MockTableCraftError extends Error {
+    statusCode: number;
+    constructor(message: string, statusCode = 500) {
+      super(message);
+      this.statusCode = statusCode;
+    }
   }
-}
+
+  return {
+    createEngines: vi.fn(),
+    createTableEngine: vi.fn(),
+    parseRequest: vi.fn(),
+    defaultCheckAccess: vi.fn(),
+    getExportMeta: vi.fn(),
+    MockTableCraftError,
+    mockState: { base: '' }
+  };
+});
 
 vi.mock('@tablecraft/engine', () => ({
   createEngines,
@@ -25,6 +38,10 @@ vi.mock('@tablecraft/engine', () => ({
   TableCraftError: MockTableCraftError,
 }));
 
+vi.mock('$app/paths', () => ({
+  get base() { return mockState.base; }
+}));
+
 import {
   createSvelteKitHandle,
   createSvelteKitHandlers,
@@ -44,6 +61,7 @@ function createEvent(urlStr: string, params: Record<string, string> = {}) {
 describe('@tablecraft/adapter-sveltekit', () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    mockState.base = '';
     parseRequest.mockReturnValue({ page: 1 });
     defaultCheckAccess.mockReturnValue(true);
     getExportMeta.mockReturnValue({
@@ -215,6 +233,79 @@ describe('@tablecraft/adapter-sveltekit', () => {
     expect(resolve).toHaveBeenCalledOnce();
   });
 
+  it('strips base path if present', async () => {
+    mockState.base = '/myapp';
+
+    const usersEngine = {
+      getConfig: vi.fn(() => ({ name: 'users' })),
+      query: vi.fn(async () => ({
+        data: [{ id: 8 }],
+        meta: { total: 1, page: 1, pageSize: 10, totalPages: 1 },
+      })),
+      exportData: vi.fn(),
+      getMetadata: vi.fn(),
+    };
+
+    createEngines.mockReturnValue({ users: usersEngine });
+
+    const handle = createSvelteKitHandle({
+      db: {},
+      schema: {},
+      configs: [],
+      prefix: '/api',
+    });
+
+    const resolve = vi.fn(async () => new Response('resolved', { status: 200 }));
+
+    const apiResponse = await handle({
+      event: createEvent('https://example.test/myapp/api/users'),
+      resolve,
+    } as any);
+
+    expect(apiResponse.status).toBe(200);
+    await expect(apiResponse.json()).resolves.toEqual({
+      data: [{ id: 8 }],
+      meta: { total: 1, page: 1, pageSize: 10, totalPages: 1 },
+    });
+    expect(resolve).not.toHaveBeenCalled();
+  });
+
+  it('does not strip base path if it is a prefix of another folder', async () => {
+    mockState.base = '/app';
+
+    const usersEngine = {
+      getConfig: vi.fn(() => ({ name: 'users' })),
+      query: vi.fn(async () => ({
+        data: [{ id: 8 }],
+        meta: { total: 1, page: 1, pageSize: 10, totalPages: 1 },
+      })),
+      exportData: vi.fn(),
+      getMetadata: vi.fn(),
+    };
+
+    createEngines.mockReturnValue({ users: usersEngine });
+
+    const handle = createSvelteKitHandle({
+      db: {},
+      schema: {},
+      configs: [],
+      prefix: '/api',
+    });
+
+    const resolve = vi.fn(async () => new Response('resolved', { status: 200 }));
+
+    // /apple is NOT under /app
+    const apiResponse = await handle({
+      event: createEvent('https://example.test/apple/api/users'),
+      resolve,
+    } as any);
+
+    // Should passthrough
+    expect(apiResponse.status).toBe(200);
+    await expect(apiResponse.text()).resolves.toBe('resolved');
+    expect(resolve).toHaveBeenCalledOnce();
+  });
+
   it('serves metadata through the hook prefix and rejects non-GET methods', async () => {
     const usersEngine = {
       getConfig: vi.fn(() => ({ name: 'users' })),