Learning Zod

Template:

• Introduction.
• Getting Started.
• Requests.

Snippets:

• Validations.
• Zod Error.

Tutorials:

• 🥳 Typescript REST API Validations with Zod by Fazt Code.

---

🪐 Introduction

Zod is a TypeScript-first schema declaration and validation library. They're using the term "schema" to broadly refer to any data type, from a simple string to a complex nested object.

• More information about Zod.

👨‍🚀 Getting Started

This repository includes a REST api template created with:

• Express: 4.18.2
• Typescript: 4.8.4
• ts-node-dev: 2.0.0
• tsconfig-paths: 4.1.0
• Zod: 3.19.1
• SWC: 0.1.57 (cli) & 1.3.11 (core).

And you will need to install Nodejs (+v18 LTS recommended) and a code editor, for example, Visual Studio Code.

1. Clone the repository:

git clone git@github.com:pheralb/learning-zod.git

2. Install dependencies:

cd learning-zod
npm install

• Note: You can use pnpm or Ultra.

3. Run the development server:

npm run dev

By default, learning-zod is running on the port 3000. You can change the port here.

🔭 Commands:

• npm run dev - Run the development server using ts-node-dev.
• npm run build - Build your rest api with SWC. It's very fast 😉.
• npm run build-tsc - If you have problems compiling with SWC, this command compiles the project with tsc.

🚀 Requests

-	Method	Url	-	Query Parameters
📋	POST	/login	Body - Json	{email: "hello@world.com", password:"mypassword123"}
📋	PUT	/products/1232?title=helloworld	Body - Json	{name: "iPhone", price:900}

✔️ Validations

Login example schema:

export const loginSchema = z.object({
  body: z.object({
    email: z.string().email({
      message: "Write a correct email address",
    }),
    password: z.string().min(6, {
      message: "Password too short",
    }),
  }),
});

🤔 Test 1 - Method: POST.

URL: http://localhost:3000/login

• JSON body:

{
  "email": 11,
  "password": []
}

• Response:

[
  {
    "field": ["email"],
    "message": "Expected string, received number"
  },
  {
    "field": ["password"],
    "message": "Expected string, received array"
  }
]

🤔 Test 2 - Method: POST.

URL: http://localhost:3000/login

• JSON body:

{
  "email": "abc",
  "password": "123456gg"
}

• Response:

[
  {
    "field": ["email"],
    "message": "Write a correct email address"
  }
]

Product example schema:

const productSchema = z.object({
  name: z.string().min(3, { message: "Name too short" }),
  price: z.number().min(0, { message: "Price must be positive" }),
});

🤔 Test 1 - Method: POST.

URL: http://localhost:3000/products

• JSON body:

{}

• Response:

[
  {
    "field": ["name"],
    "message": "Required"
  },
  {
    "field": ["price"],
    "message": "Required"
  }
]

🤔 Test 2 - Method: POST.

URL: http://localhost:3000/products

• JSON body:

{
  "name": "iPhone",
  "price": "33"
}

• Response:

[
  {
    "field": ["price"],
    "message": "Expected number, received string"
  }
]

Update product example schema:

export const updateSchema = z.object({
  name: z.string(),
  price: z.number().min(0, { message: "Price must be positive" }).optional(),
});

🤔 Test 1 - Method: PUT.

URL: http://localhost:3000/products/1

• JSON body:

{
  "name": "iPhone",
  "price": 30
}

• Response:

[
  {
    "field": ["params", "id"],
    "message": "String must contain at least 3 character(s)"
  }
]

📚 Zod Error:

In the schema we request that a field is of type "string", for example, username:

const mySchema = z.object({
  username: z.string(),
});

If we introduce a number in username field, Zod returns the following:

{
  "issues": [
    {
      "code": "invalid_type",
      "expected": "string",
      "received": "number",
      "path": ["username"],
      "message": "Expected string, received number"
    }
  ],
  "name": "ZodError"
}

🔑 License

• MIT.