Add explicit disallow feature

README.md

@@ -6,7 +6,7 @@ The parser currently supports:
 
 - User-agent:
 - Allow:
-- Disallow:
+- Disallow (with explicit mode support):
 - Sitemap:
 - Crawl-delay:
 - Host:
@@ -41,6 +41,7 @@ var robots = robotsParser('http://www.example.com/robots.txt', [
 robots.isAllowed('http://www.example.com/test.html', 'Sams-Bot/1.0'); // true
 robots.isAllowed('http://www.example.com/dir/test.html', 'Sams-Bot/1.0'); // true
 robots.isDisallowed('http://www.example.com/dir/test2.html', 'Sams-Bot/1.0'); // true
+robots.isDisallowed('http://www.example.com/dir/test2.html', 'Sams-Bot/1.0', true); // false
 robots.getCrawlDelay('Sams-Bot/1.0'); // 1
 robots.getSitemaps(); // ['http://example.com/sitemap.xml']
 robots.getPreferredHost(); // example.com
@@ -54,11 +55,12 @@ Returns true if crawling the specified URL is allowed for the specified user-age
 
 This will return `undefined` if the URL isn't valid for this robots.txt.
 
-### isDisallowed(url, [ua])
+### isDisallowed(url, [ua], [explicit])
 
 **boolean or undefined**
 
 Returns true if crawling the specified URL is not allowed for the specified user-agent.
+In explicit mode, user agents wildcards are discarded.
 
 This will return `undefined` if the URL isn't valid for this robots.txt.
 

Robots.js

@@ -361,7 +361,7 @@ Robots.prototype.setPreferredHost = function (url) {
  this._preferredHost = url;
 };
 
-Robots.prototype._getRule = function (url, ua) {
+Robots.prototype._getRule = function (url, ua, explicit) {
  var parsedUrl = parseUrl(url) || {};
  var userAgent = formatUserAgent(ua || '*');
 
@@ -374,7 +374,12 @@ Robots.prototype._getRule = function (url, ua) {
  return;
  }
 
- var rules = this._rules[userAgent] || this._rules['*'] || [];
+ var rules = this._rules[userAgent];
+ if (!explicit) {
+ rules = rules || this._rules['*']
+ }
+ rules = rules || []
+
  var path = urlEncodeToUpper(parsedUrl.pathname + parsedUrl.search);
  var rule = findRule(path, rules);
 
@@ -422,16 +427,51 @@ Robots.prototype.getMatchingLineNumber = function (url, ua) {
 };
 
 /**
- * Returns the opposite of isAllowed()
- *
+ * In standard mode, it returns the opposite of is allowed().
+ * In explicit mode, it will return:
+ * - true if the the agent is explicitly disallowed (wildcard non included),
+ * - throws an error if the user agent is not specified,
+ * - and false otherwise.
  * @param {string} url
  * @param {string} ua
  * @return {boolean}
  */
-Robots.prototype.isDisallowed = function (url, ua) {
- return !this.isAllowed(url, ua);
+Robots.prototype.isDisallowed = function (url, ua, explicit) {
+ if ((explicit === true) && (ua === undefined)) {
+ throw new Error("User Agent must be specified in explicit mode")
+ }
+
+ var rule = this._getRule(url, ua, explicit);
+ if (typeof rule === 'undefined') {
+ return true;
+ }
+ return !(!rule || rule.allow);
 };
 
+Robots.prototype.isExplicitlyDisallowed = function(url, ua) { 
+ var parsedUrl = parseUrl(url) || {};
+ var userAgent = formatUserAgent(ua);
+
+ // The base URL must match otherwise this robots.txt is not valid for it.
+ if (
+ parsedUrl.protocol !== this._url.protocol ||
+ parsedUrl.hostname !== this._url.hostname ||
+ parsedUrl.port !== this._url.port
+ ) {
+ return;
+ }
+
+ var rules = this._rules[userAgent] || [];
+ var path = urlEncodeToUpper(parsedUrl.pathname + parsedUrl.search);
+ var rule = findRule(path, rules);
+
+ if (typeof rule === 'undefined') {
+ return;
+ }
+
+ return !(!rule || rule.allow);
+}
+
 /**
  * Gets the crawl delay if there is one.
  *

index.d.ts

@@ -2,7 +2,7 @@ declare module 'robots-parser';
 
 interface Robot {
  isAllowed(url: string, ua?: string): boolean | undefined;
- isDisallowed(url: string, ua?: string): boolean | undefined;
+ isDisallowed(url: string, ua?: string, explicit?: boolean): boolean | undefined;
  getMatchingLineNumber(url: string, ua?: string): number;
  getCrawlDelay(ua?: string): number | undefined;
  getSitemaps(): string[];

test/Robots.js

@@ -861,4 +861,42 @@ describe('Robots', function () {
 
  testRobots('https://www.example.com/robots.txt', contents, allowed, disallowed);
  });
+
+ it('should not be disallowed when wildcard is used in explicit mode', function () {
+ var contents = [
+ 'User-agent: *',
+ 'Disallow: /',
+ ].join('\n')
+
+ var url = 'https://www.example.com/hello'
+ var userAgent = 'SomeBot';
+ var robots = robotsParser(url, contents);
+
+ expect(robots.isDisallowed(url, userAgent, true)).to.equal(false)
+ })
+
+ it('should be disallowed when user agent equal robots rule in explicit mode', function () {
+ var contents = [
+ 'User-agent: SomeBot',
+ 'Disallow: /',
+ ].join('\n')
+
+ var url = 'https://www.example.com/hello'
+ var userAgent = 'SomeBot';
+ var robots = robotsParser(url, contents);
+
+ expect(robots.isDisallowed(url, userAgent, true)).to.equal(true)
+ })
+
+ it('should throw an error when user agent is not set in explicit mode', function () {
+ var contents = [
+ 'User-agent: SomeBot',
+ 'Disallow: /',
+ ].join('\n')
+
+ var url = 'https://www.example.com/hello'
+ var robots = robotsParser(url, contents);
+
+ expect(robots.isDisallowed.bind(robots, url, undefined, true)).to.throw("User Agent must be specified in explicit mode")
+ }) 
 });