Merge pull request #181 from storyofams/fix/nested-folders

fix: use error stack to determine the directory

lib/createHandler.ts

@@ -1,7 +1,9 @@
 import type { NextApiHandler, NextApiRequest, NextApiResponse } from 'next';
 import { findRoute } from './internals/findRoute';
+import { getFileDirectory } from './internals/getFileDirectory';
 import { getParams } from './internals/getParams';
 import { notFound } from './internals/notFound';
+import { parseRequestUrl } from './internals/parseRequestUrl';
 
 /**
  * Prepares a router for the given class.
@@ -24,16 +26,15 @@ import { notFound } from './internals/notFound';
  */
 export function createHandler(cls: new (...args: any[]) => any): NextApiHandler {
   const instance = new cls();
+  const directory = getFileDirectory();
 
   return (req: NextApiRequest, res: NextApiResponse) => {
     if (!req.url || !req.method) {
       return notFound(req, res);
     }
 
-    const [, , , ...path] = req.url.split('?')[0].split('/');
-    const joinedPath = `/${path.join('/')}`;
-
-    const [keys, match, method] = findRoute(cls, req.method, joinedPath);
+    const path = parseRequestUrl(req.url, directory);
+    const [keys, match, method] = findRoute(cls, req.method, path);
     if (!method) {
       return notFound(req, res);
     }

lib/internals/getFileDirectory.spec.ts

@@ -0,0 +1,18 @@
+import { getFileDirectory } from './getFileDirectory';
+
+it('getFileDirectory', () => {
+  const spyError = jest.spyOn(global, 'Error');
+  spyError.mockImplementation(() => {
+    const err = {
+      name: 'Error',
+      message: 'An error occurred.',
+      stack: 'Object at (/example-path/.next/server/pages/api/tags/[id]/[[...params]].ts:1:1)'
+    };
+    return err;
+  });
+
+  const dir = getFileDirectory();
+  expect(dir).toStrictEqual('/example-path/.next/server/pages/api/tags/[id]');
+
+  spyError.mockRestore();
+});

lib/internals/getFileDirectory.ts

@@ -0,0 +1,21 @@
+import { dirname } from 'path';
+
+export function getFileDirectory(): string | undefined {
+  let directoryPath: string | undefined;
+
+  const parenthesisRegExp = /\(([^)]+)\)/;
+  const pathInError = new Error().stack
+    ?.split('at ')
+    .find(line => parenthesisRegExp.test(line) && line.includes('/.next/server/pages/api'));
+
+  /* istanbul ignore else */
+  if (pathInError) {
+    const [, pathWithRowCol] = parenthesisRegExp.exec(pathInError) ?? [];
+    /* istanbul ignore else */
+    if (pathWithRowCol) {
+      directoryPath = dirname(pathWithRowCol.replace(/:(\d+):(\d+)$/, ''));
+    }
+  }
+
+  return directoryPath;
+}

lib/internals/parseRequestUrl.spec.ts

@@ -0,0 +1,23 @@
+import { parseRequestUrl } from './parseRequestUrl';
+
+describe('parseRequestUrl', () => {
+  it('Should return "/"', () => {
+    expect(parseRequestUrl('/api/user')).toStrictEqual('/');
+  });
+
+  it('Should return "/1"', () => {
+    expect(parseRequestUrl('/api/user/1')).toStrictEqual('/1');
+  });
+
+  it('Should return "/1/articles"', () => {
+    expect(parseRequestUrl('/api/user/1/articles')).toStrictEqual('/1/articles');
+  });
+
+  it('Should return "/" when directory name is a paremeter ([id])', () =>
+    expect(parseRequestUrl('/api/user/1', '/next-api-decorators/.next/server/pages/api/user/[id]')).toStrictEqual('/'));
+
+  it('Should return "/articles" when directory name is a paremeter ([id])', () =>
+    expect(
+      parseRequestUrl('/api/user/1/articles', '/next-api-decorators/.next/server/pages/api/user/[id]')
+    ).toStrictEqual('/articles'));
+});

lib/internals/parseRequestUrl.ts

@@ -0,0 +1,17 @@
+export function parseRequestUrl(url: string, directoryPath?: string): string {
+  let path = url.split('?')[0].split('/').slice(3).join('/');
+
+  if (directoryPath) {
+    const pathRegExp = new RegExp(directoryPath.split('/.next/server/pages')[1].replace(/(\[\w+\])/, '(\\w+)'));
+    /* istanbul ignore else */
+    if (pathRegExp.test(url)) {
+      path = url.replace(pathRegExp, '');
+    }
+  }
+
+  if (!path.startsWith('/')) {
+    path = `/${path}`;
+  }
+
+  return path;
+}