Remove book_as_single_document flag and throw if book ID is missing

 - Remove the book_as_single_document flag, as we have now enabled this
   flag for everyone in production

 - Throw if the `isbn` property is missing from the book info returned
   by VitalSource. If this ever happens, we want to fail loudly instead
   of silently capturing a URL with no book ID on it.

src/annotator/features.js

@@ -11,11 +11,7 @@ import { warnOnce } from '../shared/warn-once';
  *
  * @type {string[]}
  */
-const annotatorFlags = [
-  'book_as_single_document',
-  'html_side_by_side',
-  'styled_highlight_clusters',
-];
+const annotatorFlags = ['html_side_by_side', 'styled_highlight_clusters'];
 
 /**
  * An observable container of feature flags.

src/annotator/integrations/index.js

@@ -25,9 +25,7 @@ export function createIntegration(annotator) {
 
   const vsFrameRole = vitalSourceFrameRole();
   if (vsFrameRole === 'content') {
-    return new VitalSourceContentIntegration(document.body, {
-      features: annotator.features,
-    });
+    return new VitalSourceContentIntegration(document.body);
   }
 
   return new HTMLIntegration({ features: annotator.features });

src/annotator/integrations/test/vitalsource-test.js

 import { delay, waitFor } from '../../../test-util/wait';
-import { FeatureFlags } from '../../features';
 import {
   VitalSourceInjector,
   VitalSourceContentIntegration,
@@ -59,14 +58,12 @@ function resolveURL(relativeURL) {
 }
 
 describe('annotator/integrations/vitalsource', () => {
-  let featureFlags;
   let fakeViewer;
   let FakeHTMLIntegration;
   let fakeHTMLIntegration;
   let fakeInjectClient;
 
   beforeEach(() => {
-    featureFlags = new FeatureFlags();
     fakeViewer = new FakeVitalSourceViewer();
 
     fakeHTMLIntegration = {
@@ -281,7 +278,6 @@ describe('annotator/integrations/vitalsource', () => {
 
     function createIntegration() {
       const integration = new VitalSourceContentIntegration(document.body, {
-        features: featureFlags,
         bookElement: fakeBookElement,
       });
       integrations.push(integration);
@@ -305,11 +301,6 @@ describe('annotator/integrations/vitalsource', () => {
       assert.calledWith(fakeHTMLIntegration.getAnnotatableRange, range);
     });
 
-    it('asks guest to wait for feature flags before sending document info', () => {
-      const integration = createIntegration();
-      assert.isTrue(integration.waitForFeatureFlags());
-    });
-
     it('asks sidebar to persist annotations after frame unloads', () => {
       const integration = createIntegration();
       assert.isTrue(integration.persistFrame());
@@ -415,20 +406,6 @@ describe('annotator/integrations/vitalsource', () => {
     });
 
     describe('#getMetadata', () => {
-      context('when "book_as_single_document" flag is off', () => {
-        it('returns metadata for current page/chapter', async () => {
-          const integration = createIntegration();
-          const metadata = await integration.getMetadata();
-          assert.equal(metadata.title, document.title);
-          assert.deepEqual(metadata.link, []);
-        });
-      });
-
-      context('when "book_as_single_document" flag is on', () => {
-        beforeEach(() => {
-          featureFlags.update({ book_as_single_document: true });
-        });
-
       it('returns book metadata', async () => {
         const integration = createIntegration();
         const metadata = await integration.getMetadata();
@@ -436,7 +413,6 @@ describe('annotator/integrations/vitalsource', () => {
         assert.deepEqual(metadata.link, []);
       });
     });
-    });
 
     describe('#navigateToSegment', () => {
       function createAnnotationWithSelector(selector) {
@@ -526,23 +502,7 @@ describe('annotator/integrations/vitalsource', () => {
         await urlChanged;
       });
 
-      context('when "book_as_single_document" flag is off', () => {
-        it('returns book chapter URL excluding query string', async () => {
-          const integration = createIntegration();
-          const uri = await integration.uri();
-          const parsedURL = new URL(uri);
-          assert.equal(parsedURL.hostname, document.location.hostname);
-          assert.equal(
-            parsedURL.pathname,
-            '/books/abc/epub/OPS/xhtml/chapter_001.html'
-          );
-          assert.equal(parsedURL.search, '');
-        });
-      });
-
-      context('when "book_as_single_document" flag is on', () => {
       it('returns book reader URL', async () => {
-          featureFlags.update({ book_as_single_document: true });
         const integration = createIntegration();
         const uri = await integration.uri();
         assert.equal(
@@ -550,19 +510,24 @@ describe('annotator/integrations/vitalsource', () => {
           'https://bookshelf.vitalsource.com/reader/books/TEST-BOOK-ID'
         );
       });
+
+      it('throws if book ID is missing', async () => {
+        fakeBookElement.getBookInfo = () => ({
+          format: 'epub',
+          title: 'Test book title',
+          // `isbn` field is missing
         });
 
-      it('updates when "book_as_single_document" flag changes', async () => {
-        const uriChanged = sinon.stub();
         const integration = createIntegration();
-        integration.on('uriChanged', uriChanged);
-        const uri1 = await integration.uri();
-
-        featureFlags.update({ book_as_single_document: true });
+        let error;
+        try {
+          await integration.uri();
+        } catch (err) {
+          error = err;
+        }
 
-        assert.calledOnce(uriChanged);
-        const uri2 = await integration.uri();
-        assert.notEqual(uri1, uri2);
+        assert.instanceOf(error, Error);
+        assert.equal(error.message, 'Unable to get book ID from VitalSource');
       });
     });
 

src/annotator/integrations/vitalsource.ts

@@ -12,7 +12,6 @@ import { injectClient } from '../hypothesis-injector';
 import type {
   Anchor,
   AnnotationData,
-  FeatureFlags as IFeatureFlags,
   Integration,
   SegmentInfo,
   SidebarLayout,
@@ -204,7 +203,6 @@ export class VitalSourceContentIntegration
   implements Integration
 {
   private _bookElement: MosaicBookElement;
-  private _features: IFeatureFlags;
   private _htmlIntegration: HTMLIntegration;
   private _listeners: ListenerCollection;
   private _textLayer?: ImageTextLayer;
@@ -212,16 +210,14 @@ export class VitalSourceContentIntegration
   constructor(
     /* istanbul ignore next - defaults are overridden in tests */
     container: HTMLElement = document.body,
+    /* istanbul ignore next - defaults are overridden in tests */
     options: {
-      features: IFeatureFlags;
       // Test seam
       bookElement?: MosaicBookElement;
-    }
+    } = {}
   ) {
     super();
 
-    this._features = options.features;
-
     const bookElement =
       options.bookElement ?? findBookElement(window.parent.document);
     if (!bookElement) {
@@ -232,12 +228,6 @@ export class VitalSourceContentIntegration
     }
     this._bookElement = bookElement;
 
-    // If the book_as_single_document flag changed, this will change the
-    // document URI returned by this integration.
-    this._features.on('flagsChanged', () => {
-      this.emit('uriChanged');
-    });
-
     const htmlFeatures = new FeatureFlags();
 
     // Forcibly enable the side-by-side feature for VS books. This feature is
@@ -401,7 +391,6 @@ export class VitalSourceContentIntegration
   }
 
   async getMetadata() {
-    if (this._bookIsSingleDocument()) {
     const bookInfo = this._bookElement.getBookInfo();
     return {
       title: bookInfo.title,
@@ -409,14 +398,6 @@ export class VitalSourceContentIntegration
     };
   }
 
-    // Return minimal metadata which includes only the information we really
-    // want to include.
-    return {
-      title: document.title,
-      link: [],
-    };
-  }
-
   navigateToSegment(ann: AnnotationData) {
     const selector = ann.target[0].selector?.find(
       s => s.type === 'EPUBContentSelector'
@@ -484,49 +465,15 @@ export class VitalSourceContentIntegration
   }
 
   async uri() {
-    if (this._bookIsSingleDocument()) {
     const bookInfo = this._bookElement.getBookInfo();
     const bookId = bookInfo.isbn;
-      return `https://bookshelf.vitalsource.com/reader/books/${bookId}`;
+    if (!bookId) {
+      throw new Error('Unable to get book ID from VitalSource');
     }
-
-    // An example of a typical URL for the chapter content in the Bookshelf reader is:
-    //
-    // https://jigsaw.vitalsource.com/books/9781848317703/epub/OPS/xhtml/chapter_001.html#cfi=/6/10%5B;vnd.vst.idref=chap001%5D!/4
-    //
-    // Where "9781848317703" is the VitalSource book ID ("vbid"), "chapter_001.html"
-    // is the location of the HTML page for the current chapter within the book
-    // and the `#cfi` fragment identifies the scroll location.
-    //
-    // Note that this URL is typically different than what is displayed in the
-    // iframe's `src` attribute.
-
-    // Strip off search parameters and fragments.
-    const uri = new URL(document.location.href);
-    uri.search = '';
-    return uri.toString();
+    return `https://bookshelf.vitalsource.com/reader/books/${bookId}`;
   }
 
   async scrollToAnchor(anchor: Anchor) {
     return this._htmlIntegration.scrollToAnchor(anchor);
   }
-
-  /**
-   * Return true if the feature flag to treat books as one document is enabled,
-   * as opposed to treating each chapter/segment/page as a separate document.
-   */
-  _bookIsSingleDocument(): boolean {
-    return this._features.flagEnabled('book_as_single_document');
-  }
-
-  waitForFeatureFlags() {
-    // The `book_as_single_document` flag changes the URI reported by this
-    // integration.
-    //
-    // Ask the guest to delay reporting document metadata to the sidebar until
-    // feature flags have been received. This ensures that the initial document
-    // info reported to the sidebar after a chapter navigation is consistent
-    // between the previous/new guest frames.
-    return true;
-  }
 }

src/annotator/test/guest-test.js

@@ -1451,7 +1451,7 @@ describe('Guest', () => {
     assert.isFalse(sidebarRPC().call.calledWith('documentInfoChanged'));
 
     emitSidebarEvent('featureFlagsUpdated', {
-      book_as_single_document: true,
+      some_new_feature: true,
     });
 
     await delay(0);