complexity is x it is time to do something…, visual studio code

I am using vscode for a react native app. And I am wondering if the message:

complexity is x it is time to do something…

is always useful.

Because for example I have this function:

import { API_URL } from "@env";
import { retrieveToken } from "../authentication/token";
export const fetchCategoryData = async () => {
    const token = await retrieveToken();
    try {
        if (token) {
            const response = await fetch(`${API_URL}/api/categories/main_groups/`, {
                method: "GET",
                headers: {
                    Authorization: `Token ${token}`,
                    "Content-Type": "application/json",
                },
            });
            return await response.json();
        } else {
            throw new Error(token);
        }
    } catch (error) {
        Error("can't retreive data");
    }
}

And vscode says:

complexity is 6 it is time to do something…

retrieveToken:

import AsyncStorage from "@react-native-async-storage/async-storage";

export const retrieveToken = async () => {
    try {
        const token = await AsyncStorage.getItem("Token");

        return token;
    } catch (error) {
        return null;
    }
};

Question: How to improve the function where the message says: complexity is 6 it is time to do something…?

>Solution :

the big question is: is it possible to refactor this?

Don’t use try/catch everywhere. Use it only where you can actually handle the error. Which in your example appears to be nowhere – any error needs to be handled by the caller of fetchCategoryData.

So you can simplify the whole thing to

export const retrieveToken = async () => {
    const token = await AsyncStorage.getItem("Token");
    if (!token) throw new Error('Got empty token from storage');
    return token;
}

export const fetchCategoryData = async () => {
    const token = await retrieveToken();
    const response = await fetch(`${API_URL}/api/categories/main_groups/`, {
        method: "GET",
        headers: {
            Authorization: `Token ${token}`,
            "Content-Type": "application/json",
        },
    });
    return await response.json();
}

which have a cyclomatic complexity of 2 and 1 respectively.