feat(ts): handle internal server errors and avoid failing a whole app

Part of #48

Author: php-coder

examples/ts/express/mysql/routes.ts

@@ -1,14 +1,14 @@
-import { Express, Request, Response } from 'express'
+import { Express, NextFunction, Request, Response } from 'express'
 import { Pool } from 'mysql'
 
 const register = (app: Express, pool: Pool) => {
 
-    app.get('/v1/categories/count', (req: Request, res: Response) => {
+    app.get('/v1/categories/count', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'SELECT COUNT(*) AS counter FROM categories',
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 if (rows.length === 0) {
                     res.status(404).end()
@@ -19,13 +19,13 @@ const register = (app: Express, pool: Pool) => {
         )
     })
 
-    app.get('/v1/collections/:collectionId/categories/count', (req: Request, res: Response) => {
+    app.get('/v1/collections/:collectionId/categories/count', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'SELECT COUNT(DISTINCT s.category_id) AS counter FROM collections_series cs JOIN series s ON s.id = cs.series_id WHERE cs.collection_id = :collectionId',
             { "collectionId": req.params.collectionId },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 if (rows.length === 0) {
                     res.status(404).end()
@@ -36,39 +36,39 @@ const register = (app: Express, pool: Pool) => {
         )
     })
 
-    app.get('/v1/categories', (req: Request, res: Response) => {
+    app.get('/v1/categories', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'SELECT id , name , name_ru , slug FROM categories LIMIT :limit',
             { "limit": req.query.limit },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.json(rows)
             }
         )
     })
 
-    app.post('/v1/categories', (req: Request, res: Response) => {
+    app.post('/v1/categories', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'INSERT INTO categories ( name , name_ru , slug , created_at , created_by , updated_at , updated_by ) VALUES ( :name , :name_ru , :slug , NOW() , :user_id , NOW() , :user_id )',
             { "name": req.body.name, "name_ru": req.body.name_ru, "slug": req.body.slug, "user_id": req.body.user_id },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
         )
     })
 
-    app.get('/v1/categories/:categoryId', (req: Request, res: Response) => {
+    app.get('/v1/categories/:categoryId', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'SELECT id , name , name_ru , slug FROM categories WHERE id = :categoryId',
             { "categoryId": req.params.categoryId },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 if (rows.length === 0) {
                     res.status(404).end()
@@ -79,32 +79,36 @@ const register = (app: Express, pool: Pool) => {
         )
     })
 
-    app.put('/v1/categories/:categoryId', (req: Request, res: Response) => {
+    app.put('/v1/categories/:categoryId', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'UPDATE categories SET name = :name , name_ru = :name_ru , slug = :slug , updated_at = NOW() , updated_by = :user_id WHERE id = :categoryId',
             { "name": req.body.name, "name_ru": req.body.name_ru, "slug": req.body.slug, "user_id": req.body.user_id, "categoryId": req.params.categoryId },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
         )
     })
 
-    app.delete('/v1/categories/:categoryId', (req: Request, res: Response) => {
+    app.delete('/v1/categories/:categoryId', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             'DELETE FROM categories WHERE id = :categoryId',
             { "categoryId": req.params.categoryId },
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
         )
     })
 
+    app.use((error: any, req: Request, res: Response, next: NextFunction) => {
+        console.error(error)
+        res.status(500).json({ "error": "Internal Server Error" })
+    })
 }
 
 exports.register = register;

src/templates/routes.ts.ejs

@@ -1,4 +1,4 @@
-import { Express, Request, Response } from 'express'
+import { Express, NextFunction, Request, Response } from 'express'
 import { Pool } from 'mysql'
 
 const register = (app: Express, pool: Pool) => {
@@ -21,12 +21,12 @@ endpoints.forEach(function(endpoint) {
 
         if (hasGetOne || hasGetMany) {
 %>
-    app.get('<%- path %>', (req: Request, res: Response) => {
+    app.get('<%- path %>', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             '<%- sql %>',<%- formattedParams %>
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
 <%          if (hasGetMany) { -%>
                 res.json(rows)
@@ -44,12 +44,12 @@ endpoints.forEach(function(endpoint) {
         }
         if (method.name === 'post') {
 %>
-    app.post('<%- path %>', (req: Request, res: Response) => {
+    app.post('<%- path %>', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             '<%- sql %>',<%- formattedParams %>
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
@@ -59,12 +59,12 @@ endpoints.forEach(function(endpoint) {
         }
         if (method.name === 'put') {
 %>
-    app.put('<%- path %>', (req: Request, res: Response) => {
+    app.put('<%- path %>', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             '<%- sql %>',<%- formattedParams %>
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
@@ -74,12 +74,12 @@ endpoints.forEach(function(endpoint) {
         }
         if (method.name === 'delete') {
 %>
-    app.delete('<%- path %>', (req: Request, res: Response) => {
+    app.delete('<%- path %>', (req: Request, res: Response, next: NextFunction) => {
         pool.query(
             '<%- sql %>',<%- formattedParams %>
             (err, rows, fields) => {
                 if (err) {
-                    throw err
+                    return next(err)
                 }
                 res.sendStatus(204)
             }
@@ -90,6 +90,10 @@ endpoints.forEach(function(endpoint) {
     });
 });
 %>
+    app.use((error: any, req: Request, res: Response, next: NextFunction) => {
+        console.error(error)
+        res.status(500).json({ "error": "Internal Server Error" })
+    })
 }
 
 exports.register = register;