feat: auto-gen api doc

packages/core/README.md

@@ -10,6 +10,18 @@ Copy proper `.env` to project root. (TBD: design the config process)
 yarn && yarn dev
 ```
 
-## Notes
+## OpenAPI Doc
 
-Upgrade `xo` after [this issue](https://github.com/SamVerschueren/vscode-linter-xo/issues/91) is solved.
+OpenAPI (Swagger) json is available on `http(s)://your-domain/api/swagger.json`. If you are running locally, the default URL will be `http://localhost:3001/api/swagger.json`. Consume it in the way you like.
+
+### Using ReDoc
+
+The doc website can be served by [redoc-cli](https://github.com/Redocly/redoc/blob/master/cli/README.md) in an extremely easy way:
+
+```bash
+npx redoc-cli serve http://localhost:3001/api/swagger.json
+```
+
+### Using Swagger Editor
+
+Copy the API output and paste it in the [Swagger Editor](https://editor.swagger.io/).

packages/core/package.json

@@ -7,9 +7,9 @@
   "license": "UNLICENSED",
   "private": true,
   "scripts": {
-    "build": "tsc",
+    "build": "rm -rf build/ && tsc",
     "lint": "eslint --format pretty --ext .ts src",
-    "dev": "tsc-watch --onSuccess \"node ./build/index.js\"",
+    "dev": "rm -rf build/ && tsc-watch --onSuccess \"node ./build/index.js\"",
     "prepare": "husky install"
   },
   "dependencies": {
@@ -50,6 +50,7 @@
     "eslint-formatter-pretty": "^4.1.0",
     "husky": "^6.0.0",
     "lint-staged": "^11.0.0",
+    "openapi-types": "^9.1.0",
     "prettier": "^2.3.2",
     "tsc-watch": "^4.4.0",
     "typescript": "^4.3.5"

packages/core/src/errors/RequestError/collection/swagger-errors.ts

@@ -0,0 +1,7 @@
+export enum SwaggerErrorCode {
+  InvalidZodType = 'swagger.invalid_zod_type',
+}
+
+export const swaggerErrorMessage: Record<SwaggerErrorCode, string> = {
+  [SwaggerErrorCode.InvalidZodType]: 'Invalid Zod type, please check route guard config.',
+};

packages/core/src/errors/RequestError/message.ts

@@ -2,9 +2,11 @@ import { RequestErrorCode } from './types';
 import { guardErrorMessage } from './collection/guard-errors';
 import { oidcErrorMessage } from './collection/oidc-errors';
 import { registerErrorMessage } from './collection/register-errors';
+import { swaggerErrorMessage } from './collection/swagger-errors';
 
 export const requestErrorMessage: Record<RequestErrorCode, string> = {
   ...guardErrorMessage,
   ...oidcErrorMessage,
   ...registerErrorMessage,
+  ...swaggerErrorMessage,
 };

packages/core/src/errors/RequestError/types.ts

@@ -1,10 +1,15 @@
 import { GuardErrorCode } from './collection/guard-errors';
 import { OidcErrorCode } from './collection/oidc-errors';
 import { RegisterErrorCode } from './collection/register-errors';
+import { SwaggerErrorCode } from './collection/swagger-errors';
 
-export { GuardErrorCode, OidcErrorCode, RegisterErrorCode };
+export { GuardErrorCode, OidcErrorCode, SwaggerErrorCode, RegisterErrorCode };
 
-export type RequestErrorCode = GuardErrorCode | OidcErrorCode | RegisterErrorCode;
+export type RequestErrorCode =
+  | GuardErrorCode
+  | OidcErrorCode
+  | RegisterErrorCode
+  | SwaggerErrorCode;
 
 export type RequestErrorMetadata = {
   code: RequestErrorCode;

packages/core/src/init/router.ts

@@ -1,21 +1,23 @@
 import Koa from 'koa';
 import Router from 'koa-router';
 import { Provider } from 'oidc-provider';
-import createSignInRoutes from '@/routes/sign-in';
-import createUIProxy from '@/proxies/ui';
-import createRegisterRoutes from '@/routes/register';
+import signInRoutes from '@/routes/sign-in';
+import registerRoutes from '@/routes/register';
+import uiProxy from '@/proxies/ui';
+import swaggerRoutes from '@/routes/swagger';
 
 const createRouter = (provider: Provider): Router => {
   const router = new Router({ prefix: '/api' });
 
-  router.use(createSignInRoutes(provider));
-  router.use(createRegisterRoutes());
+  router.use(signInRoutes(provider));
+  router.use(registerRoutes());
+  router.use(swaggerRoutes());
 
   return router;
 };
 
 export default function initRouter(app: Koa, provider: Provider): Router {
   const router = createRouter(provider);
-  app.use(router.routes()).use(createUIProxy()).use(router.allowedMethods());
+  app.use(router.routes()).use(uiProxy()).use(router.allowedMethods());
   return router;
 }

packages/core/src/middleware/koa-guard.ts

@@ -1,7 +1,8 @@
 import RequestError, { GuardErrorCode } from '@/errors/RequestError';
+import { has } from '@logto/essentials';
 import { Middleware } from 'koa';
 import koaBody from 'koa-body';
-import { IRouterParamContext } from 'koa-router';
+import { IMiddleware, IRouterParamContext } from 'koa-router';
 import { ZodType } from 'zod';
 
 export type GuardConfig<QueryT, BodyT, ParametersT> = {
@@ -34,6 +35,11 @@ export type WithGuardConfig<
   config: GuardConfig<GuardQueryT, GuardBodyT, GuardParametersT>;
 };
 
+export const isGuardMiddleware = <Type extends IMiddleware>(
+  function_: Type
+): function_ is WithGuardConfig<Type> =>
+  function_.name === 'guardMiddleware' && has(function_, 'config');
+
 export default function koaGuard<
   StateT,
   ContextT extends IRouterParamContext,

packages/core/src/proxies/ui.ts

@@ -1,7 +1,7 @@
 import proxy from 'koa-proxies';
 
 // CAUTION: this is for testing only
-export default function createUIProxy() {
+export default function uiProxy() {
   return proxy(/^\/(?!api|oidc).*$/, {
     target: 'http://localhost:3000',
     changeOrigin: true,

packages/core/src/routes/register.ts

@@ -22,7 +22,7 @@ const generateUserId = async (maxRetries = 500) => {
   throw new Error('Cannot generate user ID in reasonable retries');
 };
 
-export default function createRegisterRoutes() {
+export default function registerRoutes() {
   const router = new Router();
 
   router.post(

packages/core/src/routes/sign-in.ts

@@ -8,7 +8,7 @@ import { conditional } from '@logto/essentials';
 import koaGuard from '@/middleware/koa-guard';
 import { OidcErrorCode } from '@/errors/RequestError';
 
-export default function createSignInRoutes(provider: Provider) {
+export default function signInRoutes(provider: Provider) {
   const router = new Router();
 
   router.post(

packages/core/src/routes/swagger.ts

@@ -0,0 +1,63 @@
+import Router, { IMiddleware } from 'koa-router';
+import { OpenAPIV3 } from 'openapi-types';
+import { isGuardMiddleware, WithGuardConfig } from '@/middleware/koa-guard';
+import { toTitle } from '@/utils/string';
+import { zodTypeToSwagger } from '@/utils/zod';
+
+export default function swaggerRoutes() {
+  const router = new Router();
+
+  router.get('/swagger.json', async (ctx) => {
+    const routes = ctx.router.stack.map(({ path, stack, methods }) => {
+      const guard = stack.find((function_): function_ is WithGuardConfig<IMiddleware> =>
+        isGuardMiddleware(function_)
+      );
+      return { path, methods, guard };
+    });
+
+    const paths = Object.fromEntries(
+      routes.map<[string, OpenAPIV3.PathItemObject]>(({ path, methods, guard }) => {
+        const trimmedPath = path.slice(4);
+        const body = guard?.config.body;
+
+        return [
+          trimmedPath,
+          Object.fromEntries(
+            methods.map<[string, OpenAPIV3.OperationObject]>((method) => [
+              method.toLowerCase(),
+              {
+                tags: [toTitle(trimmedPath.split('/')[1] ?? 'General')],
+                requestBody: body && {
+                  required: true,
+                  content: {
+                    'application/json': {
+                      schema: zodTypeToSwagger(body),
+                    },
+                  },
+                },
+                responses: {
+                  '200': {
+                    description: 'OK',
+                  },
+                },
+              },
+            ])
+          ),
+        ];
+      })
+    );
+
+    const document: OpenAPIV3.Document = {
+      openapi: '3.0.1',
+      info: {
+        title: 'Logto Core',
+        version: '0.1.0',
+      },
+      paths,
+    };
+
+    ctx.body = document;
+  });
+
+  return router.routes();
+}

packages/core/src/utils/string.ts

@@ -0,0 +1,10 @@
+export function toTitle(string: string) {
+  if (typeof string !== 'string') {
+    throw new TypeError('Expected a string');
+  }
+
+  return string
+    .toLowerCase()
+    .replace(/(?:^|\s|-)\S/g, (x) => x.toUpperCase())
+    .replace(/-/g, ' ');
+}

packages/core/src/utils/zod.ts

@@ -0,0 +1,50 @@
+import { OpenAPIV3 } from 'openapi-types';
+import { ZodArray, ZodBoolean, ZodNumber, ZodObject, ZodOptional, ZodString } from 'zod';
+import RequestError, { SwaggerErrorCode } from '@/errors/RequestError';
+import { conditional } from '@logto/essentials';
+
+export const zodTypeToSwagger = (config: unknown): OpenAPIV3.SchemaObject => {
+  if (config instanceof ZodOptional) {
+    return zodTypeToSwagger(config._def.innerType);
+  }
+
+  if (config instanceof ZodObject) {
+    const entries = Object.entries(config.shape);
+    const required = entries
+      .filter(([, value]) => !(value instanceof ZodOptional))
+      .map(([key]) => key);
+
+    return {
+      type: 'object',
+      required: conditional(required.length > 0 && required),
+      properties: Object.fromEntries(entries.map(([key, value]) => [key, zodTypeToSwagger(value)])),
+    };
+  }
+
+  if (config instanceof ZodArray) {
+    return {
+      type: 'array',
+      items: zodTypeToSwagger(config._def.type),
+    };
+  }
+
+  if (config instanceof ZodString) {
+    return {
+      type: 'string',
+    };
+  }
+
+  if (config instanceof ZodNumber) {
+    return {
+      type: 'number',
+    };
+  }
+
+  if (config instanceof ZodBoolean) {
+    return {
+      type: 'boolean',
+    };
+  }
+
+  throw new RequestError(SwaggerErrorCode.InvalidZodType, config);
+};

packages/core/yarn.lock

@@ -3320,6 +3320,11 @@ only@~0.0.2:
   resolved "https://registry.yarnpkg.com/only/-/only-0.0.2.tgz#2afde84d03e50b9a8edc444e30610a70295edfb4"
   integrity sha1-Kv3oTQPlC5qO3EROMGEKcCle37Q=
 
+openapi-types@^9.1.0:
+  version "9.1.0"
+  resolved "https://registry.yarnpkg.com/openapi-types/-/openapi-types-9.1.0.tgz#a2ab0acc5198c1725f83d7cbe063efd1bcd0479e"
+  integrity sha512-mhXh8QN8sbErlxfxBeZ/pzgvmDn443p8CXlxwGSi2bWANZAFvjLPI0PoGjqHW+JdBbXg6uvmvM81WXaweh/SVA==
+
 optionator@^0.9.1:
   version "0.9.1"
   resolved "https://registry.yarnpkg.com/optionator/-/optionator-0.9.1.tgz#4f236a6373dae0566a6d43e1326674f50c291499"