Guard against annotation targets without fragments

__tests__/src/lib/AnnotationItem.test.js

@@ -118,6 +118,10 @@ describe('AnnotationItem', () => {
       expect(new AnnotationItem({ target: 'www.example.com/#xywh=10,10,100,200' })
         .fragmentSelector).toEqual([10, 10, 100, 200]);
     });
+    it('url without a fragment', () => {
+      expect(new AnnotationItem({ target: 'www.example.com' })
+        .fragmentSelector).toEqual(null);
+    });
   });
   describe('svgSelector', () => {
     it('simple string', () => {

__tests__/src/lib/AnnotationResource.test.js

@@ -151,6 +151,11 @@ describe('AnnotationResource', () => {
       expect(new AnnotationResource({ on: { selector: { '@type': 'oa:Choice', default: { value: 'www.example.com/#xywh=10,10,100,200' } } } })
         .fragmentSelector).toEqual([10, 10, 100, 200]);
     });
+
+    it('url without a fragment', () => {
+      expect(new AnnotationResource({ on: { selector: { value: 'www.example.com' } } })
+        .fragmentSelector).toEqual(null);
+    });
   });
   describe('svgSelector', () => {
     it('simple string', () => {

src/lib/AnnotationItem.js

@@ -104,13 +104,19 @@ export default class AnnotationItem {
   get fragmentSelector() {
     const { selector } = this;
 
+    let match;
+
     switch (typeof selector) {
       case 'string':
-        return selector.match(/xywh=(.*)$/)[1].split(',').map(str => parseInt(str, 10));
+        match = selector.match(/xywh=(.*)$/);
+        break;
       case 'object':
-        return selector.value.match(/xywh=(.*)$/)[1].split(',').map(str => parseInt(str, 10));
+        match = selector.value.match(/xywh=(.*)$/);
+        break;
       default:
         return null;
     }
+
+    return match && match[1].split(',').map(str => parseInt(str, 10));
   }
 }

src/lib/AnnotationResource.js

@@ -105,13 +105,19 @@ export default class AnnotationResource {
   get fragmentSelector() {
     const { selector } = this;
 
+    let match;
+
     switch (typeof selector) {
       case 'string':
-        return selector.match(/xywh=(.*)$/)[1].split(',').map(str => parseInt(str, 10));
+        match = selector.match(/xywh=(.*)$/);
+        break;
       case 'object':
-        return selector.value.match(/xywh=(.*)$/)[1].split(',').map(str => parseInt(str, 10));
+        match = selector.value.match(/xywh=(.*)$/);
+        break;
       default:
         return null;
     }
+
+    return match && match[1].split(',').map(str => parseInt(str, 10));
   }
 }