/
index.js
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/
index.js
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'use strict';
const urlLib = require('url');
const request = require('request');
const isImage = require('is-image');
const isUrl = require('is-url');
function handleRequestResult(error, response, callback) {
if (error || !response || !response.headers) {
callback(false);
return;
}
const contentType = response.headers['content-type'];
const hasImageContentType = contentType && contentType.search(/^image\//) !== -1;
callback(hasImageContentType);
}
function requestUrlAndLookForImageHeader(url, callback, timeout) {
if (!timeout) {
timeout = 20 * 1000;
}
try {
request.get(url, {timeout}, (error, response) => {
handleRequestResult(error, response, callback);
});
} catch {
callback(false);
}
}
function isUrlAnImageUrl(url, callback, timeout) {
const urlObject = new urlLib.URL(url);
const path = urlObject.pathname;
if (isImage(path)) {
callback(true);
return;
}
requestUrlAndLookForImageHeader(url, callback, timeout);
}
function isAnImageUrl(url, callback, timeout) {
if (!callback) {
throw new Error('Callback must be set to receive the result of the image check.');
}
if (!url) {
callback(false);
return;
}
if (!isUrl(url)) {
const result = isImage(url);
callback(result);
return;
}
isUrlAnImageUrl(url, callback, timeout);
}
module.exports = isAnImageUrl;