broken-link-checker/lib/internal/checkUrl.js

Find broken links, missing images, etc in your HTML.

"use strict";
var linkObj        = require("./linkObj");
var reasons        = require("./messages").reasons;
var simpleResponse = require("./simpleResponse");

var bhttp = require("bhttp");
var extend = require("extend");
var isString = require("is-string");



/*
	Checks a URL to see if it's broken or not.
*/
function checkUrl(link, baseUrl, cache, options, retry)
{
	var cached;
	
	if (retry === undefined)
	{
		if (isString(link) === true)
		{
			link = linkObj(link);
			linkObj.resolve(link, baseUrl, options);
		}
		
		// TODO :: move out to an `linkObj.invalidate()` to share with `HtmlChecker()` ?
		if (link.url.resolved === null)
		{
			link.broken = true;
			link.brokenReason = "BLC_INVALID";
			linkObj.clean(link);
			return Promise.resolve(link);
		}
		
		cached = cache.get(link.url.parsed);
		
		if (cached !== undefined)
		{
			return Promise.resolve(cached).then( function(response)
			{
				// Cloned to avoid unexpected mutations as a result of user changes
				response = extend({}, response);
				
				copyResponseData(response, link, options);
				
				link.http.cached = true;
				
				return link;
			});
		}
	}
	
	var request = bhttp.request(link.url.resolved,  // TODO :: https://github.com/joepie91/node-bhttp/issues/3
	{
		discardResponse: true,
		headers: { "user-agent":options.userAgent },
		method: retry!==405 ? options.requestMethod : "get"
	})
	.then( function(response)
	{
		response = simpleResponse(response);
		
		if (response.statusCode===405 && options.requestMethod==="head" && options.retry405Head===true && retry!==405)
		{
			// Retry possibly broken server with "get"
			return checkUrl(link, baseUrl, cache, options, 405);
		}
		
		// TODO :: store ALL redirected urls in cache
		if (options.cacheResponses===true && response.url!==link.url.resolved)
		{
			cache.set(response.url, response);  // TODO :: store `request` instead to be consistent?
		}
		
		return response;
	})
	.catch( function(error)
	{
		// The error will be stored as a response
		return error;
	});
	
	if (retry === undefined)
	{
		// Send response to cache -- it will be available to `cache.get()` before being resolved
		if (options.cacheResponses === true)
		{
			cache.set(link.url.parsed, request);
		}
		
		// Send linkObj to caller
		return request.then( function(response)
		{
			copyResponseData(response, link, options);
			
			link.http.cached = false;
			
			return link;
		});
	}
	else
	{
		return request;
	}
}



/*
	Copy data from a bhttp response object—either from a request or cache—
	into a link object.
*/
function copyResponseData(response, link, options)
{
	if (response instanceof Error === false)
	{
		if (response.statusCode !== 200)
		{
			link.broken = true;
			link.brokenReason = "HTTP_" + response.statusCode;
		}
		else
		{
			link.broken = false;
		}
		
		link.http.response = response;
		
		if (link.url.resolved !== response.url)
		{
			link.url.redirected = response.url;
			
			if (link.base.resolved !== null)
			{
				// TODO :: this needs a test
				linkObj.relation(link, link.url.redirected);
			}
		}
	}
	else
	{
		link.broken = true;
		
		if (reasons["ERRNO_"+response.code] != null)
		{
			link.brokenReason = "ERRNO_" + response.code;
		}
		/*else if (response.message === "Invalid URL")
		{
			link.brokenReason = "BLC_INVALID";
		}*/
		else
		{
			link.brokenReason = "BLC_UNKNOWN";
		}
	}
	
	linkObj.clean(link);
}



module.exports = checkUrl;