Simple Typed Fetch
This package provides utility functions for making HTTP requests with validation using the zod schema validation library. It handles various error cases, client and server errors, and offers an additional simpleFetch
wrapper function for easier usage.
To install the required dependencies for this package, run:
npm install simple-typed-fetch
Usage
fetchWithValidation
The fetchWithValidation
function is an async function that takes the following parameters:
url
(string): The URL to fetch data from.schema
(Schema): The zod schema for validating the response data.options
(RequestInit, optional): Optional fetch options (like method, headers, etc.).errorSchema
(Schema, optional): The zod schema for validating error responses (4xx status codes). The function returns aResult
object from theneverthrow
library, which can be either anOk
or anErr
variant. If the response is successfully validated, the function returns anOk
variant with the validated data. In case of an error, it returns anErr
variant with error details.
simpleFetch
The simpleFetch
function is a higher-order function that wraps the fetchWithValidation
function and automatically throws an error in case of an Err
result. This function is useful when you prefer working with exceptions rather than Result
objects.
Error Handling
This package uses the neverthrow
library for error handling. It provides a detailed error object in case of an error, containing the following properties:
type
(string): A string describing the error type.url
(string): The URL where the error occurred.message
(string): A human-readable error message.status
(number, optional): The HTTP status code of the response (for 4xx and 5xx status codes).error
(Error, optional): The original error object (for some error cases).text
(string, optional): The response text (for some error cases).
Examples
Here's an example of how to use the fetchWithValidation
function with a zod schema:
import { z } from "zod";
import { fetchWithValidation } from "simple-typed-fetch";
const userSchema = z.object({
id: z.number(),
name: z.string(),
});
async function fetchUser(userId: number) {
const result = await fetchWithValidation(
`https://api.example.com/users/${userId}`,
userSchema
);
if (result.isErr()) {
console.error("Error fetching user:", result.error.message);
return;
}
console.log("Fetched user:", result.value);
}
And here's an example of how to use the simpleFetch
function:
import { z } from "zod";
import { simpleFetch } from "simple-typed-fetch";
const userSchema = z.object({
id: z.number(),
name: z.string(),
});
const fetchUser = simpleFetch(async (userId: number) =>
fetchWithValidation(`https://api.example.com/users/${userId}`, userSchema)
);
(async () => {
try {
const user = await fetchUser(1);
console.log("Fetched user:", user);
} catch (error) {
console.error("Error fetching user:", error.message);
}
})();