From b1074976deff3d8f979a2ed827ded9d3c4a3c73f Mon Sep 17 00:00:00 2001
From: Anand Chowdhary <mail@anandchowdhary.com>
Date: Thu, 22 Oct 2020 18:10:29 +0530
Subject: [PATCH] :sparkles: Add pipes for optional int, order by

---
 src/modules/user/user.controller.ts | 22 +++++++++++++------
 src/modules/user/user.service.ts    |  3 ++-
 src/pipes/optional-int.pipe.ts      | 22 +++++++++++++++++++
 src/pipes/order-by.pipe.ts          | 33 +++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+), 8 deletions(-)
 create mode 100644 src/pipes/optional-int.pipe.ts
 create mode 100644 src/pipes/order-by.pipe.ts

diff --git a/src/modules/user/user.controller.ts b/src/modules/user/user.controller.ts
index a9b5c1fda..40ddf4016 100644
--- a/src/modules/user/user.controller.ts
+++ b/src/modules/user/user.controller.ts
@@ -1,6 +1,8 @@
-import { Controller, Get } from '@nestjs/common';
+import { Controller, Get, Param, ParseIntPipe, Query } from '@nestjs/common';
 import { users } from '@prisma/client';
 import { OmitSecrets } from 'src/modules/prisma/prisma.interface';
+import { OptionalIntPipe } from 'src/pipes/optional-int.pipe';
+import { OrderByPipe } from 'src/pipes/order-by.pipe';
 import { UsersService } from './user.service';
 
 @Controller('users')
@@ -8,12 +10,18 @@ export class UserController {
   constructor(private usersService: UsersService) {}
 
   @Get()
-  async getAll(): Promise<OmitSecrets<users>[]> {
-    return this.usersService.users({});
+  async getAll(
+    @Query('skip', OptionalIntPipe) skip?: number,
+    @Query('take', OptionalIntPipe) take?: number,
+    @Query('orderBy', OrderByPipe) orderBy?: Record<string, 'asc' | 'desc'>,
+  ): Promise<OmitSecrets<users>[]> {
+    return this.usersService.users({ skip, take, orderBy });
   }
 
-  // @Get('post/:id')
-  // async getPostById(@Param('id') id: string): Promise<PostModel> {
-  //   return this.postService.post({ id: Number(id) });
-  // }
+  @Get(':id')
+  async get(
+    @Param('id', ParseIntPipe) id: number,
+  ): Promise<OmitSecrets<users>> {
+    return this.usersService.user({ id: Number(id) });
+  }
 }
diff --git a/src/modules/user/user.service.ts b/src/modules/user/user.service.ts
index 90f642dad..e374c131e 100644
--- a/src/modules/user/user.service.ts
+++ b/src/modules/user/user.service.ts
@@ -1,4 +1,4 @@
-import { Injectable } from '@nestjs/common';
+import { HttpException, HttpStatus, Injectable } from '@nestjs/common';
 import { PrismaService } from '../prisma/prisma.service';
 import {
   usersUpdateInput,
@@ -20,6 +20,7 @@ export class UsersService {
     const user = await this.prisma.users.findOne({
       where: userWhereUniqueInput,
     });
+    if (!user) throw new HttpException('User not found', HttpStatus.NOT_FOUND);
     return this.prisma.expose<users>(user);
   }
 
diff --git a/src/pipes/optional-int.pipe.ts b/src/pipes/optional-int.pipe.ts
new file mode 100644
index 000000000..7809528da
--- /dev/null
+++ b/src/pipes/optional-int.pipe.ts
@@ -0,0 +1,22 @@
+import {
+  PipeTransform,
+  Injectable,
+  HttpException,
+  HttpStatus,
+  ArgumentMetadata,
+} from '@nestjs/common';
+
+/** Convert a string like "1" to a number, but without NaN */
+@Injectable()
+export class OptionalIntPipe implements PipeTransform {
+  transform(value: string, metadata: ArgumentMetadata): number | undefined {
+    if (value == null) return undefined;
+    const num = Number(value);
+    if (isNaN(num))
+      throw new HttpException(
+        `"${metadata.data}" should be a number, provided "${value}"`,
+        HttpStatus.UNPROCESSABLE_ENTITY,
+      );
+    return num;
+  }
+}
diff --git a/src/pipes/order-by.pipe.ts b/src/pipes/order-by.pipe.ts
new file mode 100644
index 000000000..badd243ea
--- /dev/null
+++ b/src/pipes/order-by.pipe.ts
@@ -0,0 +1,33 @@
+import {
+  PipeTransform,
+  Injectable,
+  HttpException,
+  HttpStatus,
+  ArgumentMetadata,
+} from '@nestjs/common';
+
+/** Convert a string like "name asc, address desc" to { name: "asc", address: "desc" } */
+@Injectable()
+export class OrderByPipe implements PipeTransform {
+  transform(
+    value: string,
+    metadata: ArgumentMetadata,
+  ): Record<string, 'asc' | 'desc'> | undefined {
+    if (value == null) return undefined;
+    try {
+      const rules = value.split(',').map(val => val.trim());
+      const orderBy: Record<string, 'asc' | 'desc'> = {};
+      rules.forEach(rule => {
+        const [key, order] = rule.split(' ');
+        if (!['asc', 'desc'].includes(order)) throw new Error();
+        rules[key] = order;
+      });
+      return orderBy;
+    } catch (_) {
+      throw new HttpException(
+        `"${metadata.data}" should be like "key1 asc, key2 desc", provided "${value}"`,
+        HttpStatus.UNPROCESSABLE_ENTITY,
+      );
+    }
+  }
+}