objectPropValidator is a lightweight, zero-dependency JavaScript utility for validating object properties against a defined schema. It's designed to be simple, flexible, and powerful, allowing for recursive validation of nested objects with clear, helpful error messages.
Whether you're validating API responses, configuration objects, or function arguments, this library ensures your data structure is correct without adding bloat to your project.
- ✅ Schema-Based Validation: Define a clear and reusable schema for your objects.
- recursi Recursive/Nested Validation: Effortlessly validate complex, nested object structures.
- 💪 Flexible Rules: Check for property
type, whether it'srequired, and add your own customvalidatorfunctions. - 🎯 Specific Error Logging: Get clear, actionable error messages in the console that pinpoint exactly what failed.
- 🕊️ Lightweight & Zero-Dependency: Tiny footprint. No external libraries needed.
- 🌐 Universal Compatibility: Works in modern browsers and Node.js environments.
You can use objectPropValidator by directly including the script in your HTML.
<scriptsrc="https://cdn.jsdelivr.net/gh/mamedul/objectpropvalidator/src/objectpropvalidator.min.js"></script>Or for npm installation
npm install objectpropvalidator
Getting started is simple. Just define a schema and create a validator function from it.
- Define a
schemathat describes the expected structure of your object. - Call
objectPropValidator(schema)to create a reusable validator function. - Use the new function to check your data object. It returns
trueorfalse.
// 1. Define the validation schemaconstuserSchema={name: {type: String,required: true},email: {type: String,required: false// This property is optional},age: {type: Number,required: true,// Add a custom validator function for more complex logicvalidator(value){constisValid=value>=18;if(!isValid){console.error("[Validation Error] User must be 18 or older.");}returnisValid;}}};// 2. Create a reusable validator functionconstvalidateUser=objectPropValidator(userSchema);// 3. Test it with some dataconstvalidUser={name: "Mamedul Islam",age: 26};constinvalidUser={name: 12345,// Wrong type// 'age' is missing};console.log("Is the first user valid?",validateUser(validUser));// trueconsole.log("Is the second user valid?",validateUser(invalidUser));// false// Console will show:// [Validation Error] Invalid type for property 'name'. Expected 'String' but received 'Number'.// [Validation Error] Missing required property: 'age'The real power of objectPropValidator comes from its ability to handle nested objects recursively. Simply set the validator property to another validator instance.
// Schema for a user objectconstuserValidator=objectPropValidator({id: {type: Number,required: true},username: {type: String,required: true}});// Schema for a blog post, which includes a nested 'author' objectconstpostSchema={title: {type: String,required: true},author: {type: Object,required: true,validator: userValidator// Use the user validator here!}};constvalidatePost=objectPropValidator(postSchema);constvalidPost={title: "My First Post",author: {id: 1,username: "mamedul"}};constinvalidPost={title: "Another Post",author: {id: "2"// Invalid type, should be Number}};console.log(validatePost(validPost));// trueconsole.log(validatePost(invalidPost));// false// Console will show:// [Validation Error] Invalid type for property 'id'. Expected 'Number' but received 'String'.You can pass a configuration object as the second argument to control how errors are logged.
constconfig={logLevel: 'warn'// Use console.warn instead of the default console.error};constmyValidator=objectPropValidator(mySchema,config);logLevel: Can be'error'(default),'warn', or'log'.
Creates and returns a new validator function.
schema(Object): An object where each key is a property to validate. The value is an object containing the validation rules.config(Object, optional): Configuration options.logLevel(String): Sets the console logging method. Defaults to'error'.
For each property in your schema, you can define the following rules:
type(Constructor | Array<Constructor>): The expected type (e.g.,String,Number,Object,Array). You can also provide an array for multiple allowed types, like[String, Number].required(Boolean): Iftrue, the property must exist in the object being validated.validator(Function): A custom function that receives the property's value and should returntrueif valid, andfalseotherwise. This is also the mechanism for nested validation.
Contributions are welcome! Please feel free to submit a pull request or open an issue on the GitHub repository.
This project is licensed under the MIT License. Copyright (c) 2022 by Mamedul Islam.
See the LICENSE file for more details.
This project was created and is maintained by Mamedul Islam.
I am a passionate web developer with experience in creating interactive and user-friendly web components. I am currently available for freelance projects or full-time opportunities.
I help businesses grow their online presence with custom web solutions. Specializing in WordPress, WooCommerce, and Shopify, I build modern, responsive, and high-performance websites.
- WhatsApp: message me
- Portfolio: mamedul.github.io
- GitHub: @mamedul
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- Twitter (X): @mamedul
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