Refactor AnnotationUser per conventions

Refactor AnnotationUser to be more "dumb" like other leafy components

src/sidebar/components/Annotation/AnnotationHeader.js

 import { SvgIcon } from '@hypothesis/frontend-shared';
 import { useMemo } from 'preact/hooks';
+import { withServices } from '../../service-context';
 
 import { useStoreProxy } from '../../store/use-store';
+import { isThirdPartyUser, username } from '../../helpers/account-id';
 import {
   domainAndTitle,
   isHighlight,
   isReply,
   hasBeenEdited,
 } from '../../helpers/annotation-metadata';
+import { annotationDisplayName } from '../../helpers/annotation-user';
 import { isPrivate } from '../../helpers/permissions';
 
 import Button from '../Button';
@@ -19,6 +22,8 @@ import AnnotationUser from './AnnotationUser';
 
 /**
  * @typedef {import("../../../types/api").Annotation} Annotation
+ * @typedef {import('../../services/service-url').ServiceUrlGetter} ServiceUrlGetter
+ * @typedef {import('../../../types/config').MergedConfig} MergedConfig
  */
 
 /**
@@ -27,6 +32,9 @@ import AnnotationUser from './AnnotationUser';
  * @prop {boolean} [isEditing] - Whether the annotation is actively being edited
  * @prop {number} replyCount - How many replies this annotation currently has
  * @prop {boolean} threadIsCollapsed - Is this thread currently collapsed?
+ * @prop {ServiceUrlGetter} serviceUrl - Injected service
+ * @prop {MergedConfig} settings - Injected
+ *
  */
 
 /**
@@ -36,13 +44,37 @@ import AnnotationUser from './AnnotationUser';
  *
  * @param {AnnotationHeaderProps} props
  */
-export default function AnnotationHeader({
+function AnnotationHeader({
   annotation,
   isEditing,
   replyCount,
   threadIsCollapsed,
+  serviceUrl,
+  settings,
 }) {
   const store = useStoreProxy();
+  const authDomain = store.authDomain();
+  const displayNamesEnabled = store.isFeatureEnabled('client_display_names');
+
+  const isThirdParty = isThirdPartyUser(annotation.user, authDomain);
+  const authorDisplayName = annotationDisplayName(
+    annotation,
+    isThirdParty,
+    displayNamesEnabled
+  );
+
+  const authorLink = (() => {
+    if (!isThirdParty) {
+      return serviceUrl('user', { user: annotation.user });
+    } else {
+      return (
+        (settings.usernameUrl &&
+          `${settings.usernameUrl}${username(annotation.user)}`) ??
+        undefined
+      );
+    }
+  })();
+
   const isCollapsedReply = isReply(annotation) && threadIsCollapsed;
 
   const annotationIsPrivate = isPrivate(annotation.permissions);
@@ -96,7 +128,10 @@ export default function AnnotationHeader({
             title="This annotation is visible only to you"
           />
         )}
-        <AnnotationUser annotation={annotation} />
+        <AnnotationUser
+          authorLink={authorLink}
+          displayName={authorDisplayName}
+        />
         {showReplyButton && (
           <Button
             className="AnnotationHeader__reply-toggle"
@@ -143,3 +178,7 @@ export default function AnnotationHeader({
     </header>
   );
 }
+
+AnnotationHeader.injectedProps = ['serviceUrl', 'settings'];
+
+export default withServices(AnnotationHeader);

src/sidebar/components/Annotation/AnnotationUser.js

-import { isThirdPartyUser, username } from '../../helpers/account-id';
-import { annotationDisplayName } from '../../helpers/annotation-user';
-import { withServices } from '../../service-context';
-
 /**
  * @typedef {import("../../../types/api").Annotation} Annotation
- * @typedef {import('../../../types/config').MergedConfig} MergedConfig
- * @typedef {import('../../services/service-url').ServiceUrlGetter} ServiceUrlGetter
  */
 
 /**
  * @typedef AnnotationUserProps
- * @prop {Annotation} annotation - The annotation whose user is relevant
- * @prop {Object} features - Injected service
- * @prop {ServiceUrlGetter} serviceUrl - Injected service
- * @prop {MergedConfig} settings - Injected service
+ * @prop {string} [authorLink]
+ * @prop {string} displayName
  */
 
 /**
@@ -22,30 +14,13 @@ import { withServices } from '../../service-context';
  *
  * @param {AnnotationUserProps} props
  */
-function AnnotationUser({ annotation, features, serviceUrl, settings }) {
-  const user = annotation.user;
-  const isFirstPartyUser = !isThirdPartyUser(user, settings.authDomain);
-  const username_ = username(user);
-
-  // How should the user's name be displayed?
-  const displayName = annotationDisplayName(
-    annotation,
-    !isFirstPartyUser,
-    features.flagEnabled('client_display_names')
-  );
-
-  const shouldLinkToActivity = isFirstPartyUser || settings.usernameUrl;
-
-  if (shouldLinkToActivity) {
+function AnnotationUser({ authorLink, displayName }) {
+  if (authorLink) {
     return (
       <div className="AnnotationUser">
         <a
           className="AnnotationUser__link"
-          href={
-            isFirstPartyUser
-              ? serviceUrl('user', { user })
-              : `${settings.usernameUrl}${username_}`
-          }
+          href={authorLink}
           target="_blank"
           rel="noopener noreferrer"
         >
@@ -62,6 +37,4 @@ function AnnotationUser({ annotation, features, serviceUrl, settings }) {
   );
 }
 
-AnnotationUser.injectedProps = ['features', 'serviceUrl', 'settings'];
-
-export default withServices(AnnotationUser);
+export default AnnotationUser;

src/sidebar/components/Annotation/test/AnnotationHeader-test.js

@@ -8,11 +8,15 @@ import mockImportedComponents from '../../../../test-util/mock-imported-componen
 import AnnotationHeader, { $imports } from '../AnnotationHeader';
 
 describe('AnnotationHeader', () => {
+  let fakeAccountId;
+  let fakeAnnotationDisplayName;
   let fakeDomainAndTitle;
   let fakeIsHighlight;
   let fakeIsReply;
   let fakeHasBeenEdited;
   let fakeIsPrivate;
+  let fakeServiceUrl;
+  let fakeSettings;
   let fakeStore;
 
   const createAnnotationHeader = props => {
@@ -22,6 +26,8 @@ describe('AnnotationHeader', () => {
         isEditing={false}
         replyCount={0}
         threadIsCollapsed={false}
+        serviceUrl={fakeServiceUrl}
+        settings={fakeSettings}
         {...props}
       />
     );
@@ -34,7 +40,19 @@ describe('AnnotationHeader', () => {
     fakeHasBeenEdited = sinon.stub().returns(false);
     fakeIsPrivate = sinon.stub();
 
+    fakeAccountId = {
+      isThirdPartyUser: sinon.stub().returns(false),
+      username: sinon.stub().returnsArg(0),
+    };
+
+    fakeAnnotationDisplayName = sinon.stub().returns('Robbie Burns');
+
+    fakeServiceUrl = sinon.stub().returns('http://example.com');
+    fakeSettings = { usernameUrl: 'http://foo.bar/' };
+
     fakeStore = {
+      authDomain: sinon.stub().returns('foo.com'),
+      isFeatureEnabled: sinon.stub().returns(false),
       route: sinon.stub().returns('sidebar'),
       setExpanded: sinon.stub(),
     };
@@ -42,12 +60,16 @@ describe('AnnotationHeader', () => {
     $imports.$mock(mockImportedComponents());
     $imports.$mock({
       '../../store/use-store': { useStoreProxy: () => fakeStore },
+      '../../helpers/account-id': fakeAccountId,
       '../../helpers/annotation-metadata': {
         domainAndTitle: fakeDomainAndTitle,
         isHighlight: fakeIsHighlight,
         isReply: fakeIsReply,
         hasBeenEdited: fakeHasBeenEdited,
       },
+      '../../helpers/annotation-user': {
+        annotationDisplayName: fakeAnnotationDisplayName,
+      },
       '../../helpers/permissions': {
         isPrivate: fakeIsPrivate,
       },
@@ -84,6 +106,47 @@ describe('AnnotationHeader', () => {
     });
   });
 
+  describe('annotation author (user) information', () => {
+    it('should link to author activity if first-party', () => {
+      fakeAccountId.isThirdPartyUser.returns(false);
+
+      const wrapper = createAnnotationHeader();
+
+      assert.equal(
+        wrapper.find('AnnotationUser').props().authorLink,
+        'http://example.com'
+      );
+    });
+
+    it('should link to author activity if third-party and has settings URL', () => {
+      fakeAccountId.isThirdPartyUser.returns(true);
+      const fakeAnnotation = fixtures.defaultAnnotation();
+
+      const wrapper = createAnnotationHeader({ annotation: fakeAnnotation });
+
+      assert.equal(
+        wrapper.find('AnnotationUser').props().authorLink,
+        `http://foo.bar/${fakeAnnotation.user}`
+      );
+    });
+
+    it('should not link to author if third-party and no settings URL', () => {
+      fakeAccountId.isThirdPartyUser.returns(true);
+
+      const wrapper = createAnnotationHeader({ settings: {} });
+
+      assert.isUndefined(wrapper.find('AnnotationUser').props().authorLink);
+    });
+
+    it('should pass the display name to AnnotationUser', () => {
+      const wrapper = createAnnotationHeader();
+      assert.equal(
+        wrapper.find('AnnotationUser').props().displayName,
+        'Robbie Burns'
+      );
+    });
+  });
+
   describe('expand replies toggle button', () => {
     const findReplyButton = wrapper =>
       wrapper.find('Button').filter('.AnnotationHeader__reply-toggle');

src/sidebar/components/Annotation/test/AnnotationUser-test.js

 import { mount } from 'enzyme';
 
 import { checkAccessibility } from '../../../../test-util/accessibility';
-import mockImportedComponents from '../../../../test-util/mock-imported-components';
 
-import AnnotationUser, { $imports } from '../AnnotationUser';
+import AnnotationUser from '../AnnotationUser';
 
 describe('AnnotationUser', () => {
-  let fakeAnnotation;
-  let fakeAnnotationUser;
-  let fakeFeatures;
-  let fakeIsThirdPartyUser;
-  let fakeServiceUrl;
-  let fakeSettings;
-  let fakeUsername;
-
-  const createAnnotationUser = () => {
-    return mount(
-      <AnnotationUser
-        annotation={fakeAnnotation}
-        features={fakeFeatures}
-        serviceUrl={fakeServiceUrl}
-        settings={fakeSettings}
-      />
-    );
+  const createAnnotationUser = props => {
+    return mount(<AnnotationUser displayName="Filbert Bronzo" {...props} />);
   };
 
-  beforeEach(() => {
-    fakeAnnotation = {
-      user: 'someone@hypothes.is',
-    };
-    fakeAnnotationUser = {
-      annotationDisplayName: sinon
-        .stub()
-        .callsFake(annotation => annotation.user),
-    };
-    fakeFeatures = { flagEnabled: sinon.stub() };
-    fakeIsThirdPartyUser = sinon.stub().returns(false);
-    fakeServiceUrl = sinon.stub();
-    fakeSettings = {};
-    fakeUsername = sinon.stub();
-
-    $imports.$mock(mockImportedComponents());
-    $imports.$mock({
-      '../../helpers/account-id': {
-        isThirdPartyUser: fakeIsThirdPartyUser,
-        username: fakeUsername,
-      },
-      '../../helpers/annotation-user': fakeAnnotationUser,
+  it('links to the author activity page if link provided', () => {
+    const wrapper = createAnnotationUser({
+      authorLink: 'http://www.foo.bar/baz',
     });
-  });
 
-  afterEach(() => {
-    $imports.$restore();
+    assert.isTrue(wrapper.find('a[href="http://www.foo.bar/baz"]').exists());
   });
 
-  describe('link to user activity', () => {
-    context('first-party user', () => {
-      it('should provide a link to the user profile', () => {
-        fakeIsThirdPartyUser.returns(false);
-        fakeServiceUrl.returns('link-to-user');
-
-        const wrapper = createAnnotationUser();
-        const linkEl = wrapper.find('a');
-
-        assert.isOk(linkEl.exists());
-        assert.calledWith(fakeServiceUrl, 'user', {
-          user: fakeAnnotation.user,
-        });
-        assert.equal(linkEl.prop('href'), 'link-to-user');
-      });
-    });
-
-    context('third-party user', () => {
-      beforeEach(() => {
-        fakeIsThirdPartyUser.returns(true);
-      });
+  it('does not link to the author activity page if no link provided', () => {
+    const wrapper = createAnnotationUser();
 
-      it('should link to user if `settings.usernameUrl` is set', () => {
-        fakeSettings.usernameUrl = 'http://example.com?user=';
-        fakeUsername.returns('elephant');
-
-        const wrapper = createAnnotationUser();
-        const linkEl = wrapper.find('a');
-
-        assert.isOk(linkEl.exists());
-        assert.equal(linkEl.prop('href'), 'http://example.com?user=elephant');
-      });
-
-      it('should not link to user if `settings.usernameUrl` is not set', () => {
-        const wrapper = createAnnotationUser();
-        const linkEl = wrapper.find('a');
-
-        assert.isNotOk(linkEl.exists());
-      });
-    });
+    assert.isFalse(wrapper.find('a').exists());
   });
 
-  it('renders the annotation author name', () => {
-    fakeFeatures.flagEnabled.withArgs('client_display_names').returns(true);
-
-    createAnnotationUser();
+  it('renders the author name', () => {
+    const wrapper = createAnnotationUser();
 
-    assert.calledWith(
-      fakeAnnotationUser.annotationDisplayName,
-      fakeAnnotation,
-      false,
-      true
-    );
+    assert.equal(wrapper.text(), 'Filbert Bronzo');
   });
 
   it(