Rename PDF => PDFIntegration and move to `src/annotator/integrations`

Create an `integrations` directory within `src/annotator` which will
house the `*Integration` classes that encapsulate document
type/viewer-specific functionality, and create the first version of the
PDF integration by moving/renaming the existing `PDF` class. The
supporting `PDFMetadata` class has also been moved.

Per recently agreed code conventions [1], the `PDFIntegration` and
`PDFMetadata` classes are no longer default exports.

[1] https://github.com/hypothesis/frontend-toolkit/blob/master/docs/js-guide.md#default-exports

src/annotator/guest.js

 import scrollIntoView from 'scroll-into-view';
 
 import { Adder } from './adder';
+import { PDFIntegration } from './integrations/pdf';
 import CrossFrame from './plugin/cross-frame';
 import DocumentMeta from './plugin/document';
-import PDFIntegration from './plugin/pdf';
 
 import * as htmlAnchoring from './anchoring/html';
 import { TextRange } from './anchoring/text-range';

src/annotator/plugin/pdf-metadata.js → src/annotator/integrations/pdf-metadata.js

@@ -59,7 +59,7 @@ function pdfViewerInitialized(app) {
  *    // Do something with the URL of the PDF.
  * })
  */
-export default class PDFMetadata {
+export class PDFMetadata {
   /**
    * Construct a `PDFMetadata` that returns URIs/metadata associated with a
    * given PDF viewer.

src/annotator/plugin/pdf.js → src/annotator/integrations/pdf.js

@@ -7,7 +7,7 @@ import RenderingStates from '../pdfjs-rendering-states';
 import { createShadowRoot } from '../util/shadow-root';
 import { ListenerCollection } from '../util/listener-collection';
 
-import PDFMetadata from './pdf-metadata';
+import { PDFMetadata } from './pdf-metadata';
 
 /**
  * @typedef {import('../../types/annotator').Anchor} Anchor
@@ -21,7 +21,7 @@ import PDFMetadata from './pdf-metadata';
 // is enough room. Otherwise, allow sidebar to overlap PDF
 const MIN_PDF_WIDTH = 680;
 
-export default class PDF {
+export class PDFIntegration {
   /**
    * @param {Annotator} annotator
    */

src/annotator/plugin/test/pdf-metadata-test.js → src/annotator/integrations/test/pdf-metadata-test.js

 import EventEmitter from 'tiny-emitter';
 
-import PDFMetadata from '../pdf-metadata';
+import { PDFMetadata } from '../pdf-metadata';
 
 /**
  * Fake implementation of PDF.js `window.PDFViewerApplication.metadata`.
@@ -126,7 +126,7 @@ function delay(ms) {
   return new Promise(resolve => setTimeout(resolve, ms));
 }
 
-describe('annotator/plugin/pdf-metadata', function () {
+describe('PDFMetadata', function () {
   [
     {
       // PDF.js < 1.6.210: `documentload` event dispatched via DOM.

src/annotator/plugin/test/pdf-test.js → src/annotator/integrations/test/pdf-test.js

-import PDF, { $imports } from '../pdf';
+import { PDFIntegration, $imports } from '../pdf';
 
 import FakePDFViewerApplication from '../../anchoring/test/fake-pdf-viewer-application';
 
@@ -14,7 +14,7 @@ function awaitEvent(target, eventName) {
   });
 }
 
-describe('annotator/plugin/pdf', () => {
+describe('PDFIntegration', () => {
   // Fake for the top-level `#outerContainer` DOM element created by PDF.js.
   let outerContainer;
   // Fake for the `#viewerContainer` DOM element created by PDF.js that contains
@@ -25,10 +25,10 @@ describe('annotator/plugin/pdf', () => {
   let fakePdfAnchoring;
   let fakePDFMetadata;
   let fakePDFViewerApplication;
-  let pdfPlugin;
+  let pdfIntegration;
 
-  function createPDFPlugin() {
-    return new PDF(fakeAnnotator);
+  function createPDFIntegration() {
+    return new PDFIntegration(fakeAnnotator);
   }
 
   beforeEach(() => {
@@ -63,7 +63,7 @@ describe('annotator/plugin/pdf', () => {
     };
 
     $imports.$mock({
-      './pdf-metadata': sinon.stub().returns(fakePDFMetadata),
+      './pdf-metadata': { PDFMetadata: sinon.stub().returns(fakePDFMetadata) },
       '../anchoring/pdf': fakePdfAnchoring,
 
       // Disable debouncing of updates.
@@ -72,7 +72,7 @@ describe('annotator/plugin/pdf', () => {
   });
 
   afterEach(() => {
-    pdfPlugin?.destroy();
+    pdfIntegration?.destroy();
     delete window.PDFViewerApplication;
     outerContainer.remove();
     $imports.$restore();
@@ -86,7 +86,7 @@ describe('annotator/plugin/pdf', () => {
 
   describe('#constructor', () => {
     it('adds CSS classes to override PDF.js styles', () => {
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
       assert.isTrue(pdfViewerHasClass('has-transparent-text-layer'));
     });
   });
@@ -100,7 +100,7 @@ describe('annotator/plugin/pdf', () => {
     if (!selection.isCollapsed) {
       selection.collapseToStart();
     }
-    pdfPlugin = createPDFPlugin();
+    pdfIntegration = createPDFIntegration();
     assert.isFalse(pdfViewerHasClass('is-selecting'));
 
     // Make the selection non-empty.
@@ -121,10 +121,10 @@ describe('annotator/plugin/pdf', () => {
 
   describe('#destroy', () => {
     it('removes CSS classes to override PDF.js styles', () => {
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
-      pdfPlugin.destroy();
-      pdfPlugin = null;
+      pdfIntegration.destroy();
+      pdfIntegration = null;
 
       assert.isFalse(
         fakePDFViewerApplication.pdfViewer.viewer.classList.contains(
@@ -141,7 +141,7 @@ describe('annotator/plugin/pdf', () => {
   it('does not show a warning when PDF has selectable text', async () => {
     fakePdfAnchoring.documentHasText.resolves(true);
 
-    pdfPlugin = createPDFPlugin();
+    pdfIntegration = createPDFIntegration();
     await delay(0); // Wait for text check to complete.
 
     assert.called(fakePdfAnchoring.documentHasText);
@@ -151,7 +151,7 @@ describe('annotator/plugin/pdf', () => {
   it('does not show a warning if PDF does not load', async () => {
     fakePDFMetadata.getUri.rejects(new Error('Something went wrong'));
 
-    pdfPlugin = createPDFPlugin();
+    pdfIntegration = createPDFIntegration();
     await delay(0); // Wait for text check to complete.
 
     assert.notCalled(fakePdfAnchoring.documentHasText);
@@ -161,7 +161,7 @@ describe('annotator/plugin/pdf', () => {
   it('shows a warning when PDF has no selectable text', async () => {
     fakePdfAnchoring.documentHasText.resolves(false);
 
-    pdfPlugin = createPDFPlugin();
+    pdfIntegration = createPDFIntegration();
     await delay(0); // Wait for text check to complete.
 
     assert.called(fakePdfAnchoring.documentHasText);
@@ -194,7 +194,7 @@ describe('annotator/plugin/pdf', () => {
 
     it('re-anchors annotations whose highlights are no longer in the page', async () => {
       const anchor = createAnchor();
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
       await triggerUpdate();
 
@@ -205,7 +205,7 @@ describe('annotator/plugin/pdf', () => {
 
     it('does not re-anchor annotations whose highlights are still in the page', async () => {
       const anchor = createAnchor();
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
       document.body.appendChild(anchor.highlights[0]);
       await triggerUpdate();
@@ -227,9 +227,9 @@ describe('annotator/plugin/pdf', () => {
       container.id = 'viewerContainer';
       document.body.appendChild(container);
 
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
-      assert.equal(pdfPlugin.contentContainer(), container);
+      assert.equal(pdfIntegration.contentContainer(), container);
     });
   });
 
@@ -245,9 +245,9 @@ describe('annotator/plugin/pdf', () => {
 
     it('resizes and activates side-by-side mode when sidebar expanded', () => {
       sandbox.stub(window, 'innerWidth').value(1350);
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
-      const active = pdfPlugin.fitSideBySide({
+      const active = pdfIntegration.fitSideBySide({
         expanded: true,
         width: 428,
         height: 728,
@@ -269,9 +269,9 @@ describe('annotator/plugin/pdf', () => {
       it('activates side-by-side mode for each relative zoom mode', () => {
         fakePDFViewerApplication.pdfViewer.currentScaleValue = zoomMode;
         sandbox.stub(window, 'innerWidth').value(1350);
-        pdfPlugin = createPDFPlugin();
+        pdfIntegration = createPDFIntegration();
 
-        const active = pdfPlugin.fitSideBySide({
+        const active = pdfIntegration.fitSideBySide({
           expanded: true,
           width: 428,
           height: 728,
@@ -285,9 +285,9 @@ describe('annotator/plugin/pdf', () => {
 
     it('deactivates side-by-side mode when sidebar collapsed', () => {
       sandbox.stub(window, 'innerWidth').value(1350);
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
-      const active = pdfPlugin.fitSideBySide({
+      const active = pdfIntegration.fitSideBySide({
         expanded: false,
         width: 428,
         height: 728,
@@ -299,9 +299,9 @@ describe('annotator/plugin/pdf', () => {
 
     it('does not activate side-by-side mode if there is not enough room', () => {
       sandbox.stub(window, 'innerWidth').value(800);
-      pdfPlugin = createPDFPlugin();
+      pdfIntegration = createPDFIntegration();
 
-      const active = pdfPlugin.fitSideBySide({
+      const active = pdfIntegration.fitSideBySide({
         expanded: true,
         width: 428,
         height: 728,

src/annotator/test/guest-test.js

@@ -114,11 +114,11 @@ describe('Guest', () => {
       './anchoring/text-range': {
         TextRange: FakeTextRange,
       },
+      './integrations/pdf': { PDFIntegration: PdfIntegration },
       './highlighter': highlighter,
       './range-util': rangeUtil,
       './plugin/cross-frame': CrossFrame,
       './plugin/document': DocumentMeta,
-      './plugin/pdf': PdfIntegration,
       './selection-observer': {
         SelectionObserver: FakeSelectionObserver,
       },