Only single copy of FanFiction chapters.

resolves #135

plugin/js/parsers/FanFictionParser.js

@@ -21,7 +21,19 @@ class FanFictionParser extends Parser {
             // no list of chapters found, assume it's a single chapter story
             return Promise.resolve(that.singleChapterStory(baseUrl, dom));
         } else {
-            return Promise.resolve(options.map(option => that.optionToChapterInfo(baseUrl, option)));
+            let foundUrls = new Set();
+            let isUnique = function(chapterInfo) {
+                let unique = !foundUrls.has(chapterInfo.sourceUrl);
+                if (unique) {
+                    foundUrls.add(chapterInfo.sourceUrl);
+                }
+                return unique;
+            }
+
+            return Promise.resolve(
+                options.map(option => that.optionToChapterInfo(baseUrl, option))
+                .filter(isUnique)
+            );
         }
     }
 

testdata/FanFiction.html

@@ -25,6 +25,13 @@
                         <p>If you're like me, you will have...</p>
                     </div>
                 </div>
+                <span style="float:right; "><select id="chap_select" title="Chapter Navigation" name="chapter" onchange="self.location = &#39;/s/1234567/&#39;+ this.options[this.selectedIndex].value + &#39;/WebToEpub&#39;;">
+                    <option value="1" selected="">1. Introduction</option>
+                    <option value="2">2. Using the Code or "How to load an Extension into Chrome"</option>
+                    <option value="3">3. Basics of Building a Chrome extension</option>
+                    <option value="4">4. How to read the HTML of a web page on a Chrome tab.</option>
+                    <option value="5">5. Using Chrome's &quot;Inspect Element&quot; to examine the DOM</option>
+                </select></span>
             </div>
         </div>
     </div>