A simple module to abstract the details of fetch API for simple calls.

fetcher.js

export class ApiError extends Error {
	constructor(message) {
		super(message);
		this.name = 'ApiError';
	}
}

export default {
	fetch: (url, fetchOptions) => {
		return fetch(url, fetchOptions)
			.then((response) => {
				let bodyPromise;
				// Processing JSON especially
				if ((response.headers.get('content-type') || []).indexOf('application/json') !== -1) {
					bodyPromise = response.json();
				} else {
					// Falling back to "text"
					bodyPromise = response.text();
				}

				if (!response.ok || Math.floor(response.status / 100) !== 2) {
					return new Promise((resolve, reject) => {
						bodyPromise.then((body) => {
							const error = new ApiError(`${url}: ${response.statusText}`);
							error.response = response;
							error.body = body;
							reject(error);
						});
					});
				}
				return bodyPromise;
			});
	}
};