Make page note tab auto-select even if page notes have replies

Before, the page notes tab would not be selected if any of the page
notes had replies. Now will correctly auto-select page notes tab if
all top-level (i.e. non-reply) annotations are page notes.

Also add some rudimentary tests for the `ADD_ANNOTATIONS` reducer in
the `selection` store module as none existed.

Fixes #1827

src/sidebar/store/modules/selection.js

@@ -19,8 +19,7 @@ import immutable from 'seamless-immutable';
 
 import uiConstants from '../../ui-constants';
 import * as metadata from '../../util/annotation-metadata';
-import * as arrayUtil from '../../util/array';
-import { toSet } from '../../util/array';
+import { countIf, toSet } from '../../util/array';
 import * as util from '../util';
 
 /**
@@ -204,14 +203,18 @@ const update = {
     return setTab(state.selectedTab, action.tab);
   },
 
+  /**
+   * Automatically select the Page Notes tab, for convenience, if all of the
+   * top-level annotations in `action.annotations` are Page Notes and the
+   * previous annotation count was 0 (i.e. collection empty).
+   */
   ADD_ANNOTATIONS(state, action) {
-    const noteCount = arrayUtil.countIf(
-      action.annotations,
-      metadata.isPageNote
+    const topLevelAnnotations = action.annotations.filter(
+      annotation => !metadata.isReply(annotation)
     );
-    // If there are no annotations at all, ADD_ANNOTATIONS will not be called.
-    const haveOnlyPageNotes = noteCount === action.annotations.length;
-    // If this is the init phase and there are only page notes, select the page notes tab.
+    const noteCount = countIf(action.annotations, metadata.isPageNote);
+
+    const haveOnlyPageNotes = noteCount === topLevelAnnotations.length;
     if (action.currentAnnotationCount === 0 && haveOnlyPageNotes) {
       return { selectedTab: uiConstants.TAB_NOTES };
     }
@@ -228,7 +231,7 @@ const update = {
     let selectedTab = state.selectedTab;
     if (
       selectedTab === uiConstants.TAB_ORPHANS &&
-      arrayUtil.countIf(action.remainingAnnotations, metadata.isOrphan) === 0
+      countIf(action.remainingAnnotations, metadata.isOrphan) === 0
     ) {
       selectedTab = uiConstants.TAB_ANNOTATIONS;
     }

src/sidebar/store/modules/test/selection-test.js

@@ -2,6 +2,7 @@ import uiConstants from '../../../ui-constants';
 import createStore from '../../create-store';
 import annotations from '../annotations';
 import selection from '../selection';
+import * as fixtures from '../../../test/annotation-fixtures';
 
 describe('sidebar/store/modules/selection', () => {
   let store;
@@ -423,4 +424,59 @@ describe('sidebar/store/modules/selection', () => {
       assert.equal(getSelectionState().sortKey, 'Newest');
     });
   });
+
+  describe('ADD_ANNOTATIONS', () => {
+    it('should select the page notes tab if all top-level annotations are page notes', () => {
+      store.dispatch({
+        type: 'ADD_ANNOTATIONS',
+        annotations: [fixtures.oldPageNote(), fixtures.oldPageNote()],
+        currentAnnotationCount: 0,
+      });
+
+      assert.equal(getSelectionState().selectedTab, uiConstants.TAB_NOTES);
+    });
+
+    it('should select the page notes tab if page notes have replies', () => {
+      const pageNote = fixtures.oldPageNote();
+      const reply = fixtures.newReply();
+      reply.references = [pageNote.id];
+      store.dispatch({
+        type: 'ADD_ANNOTATIONS',
+        annotations: [pageNote, reply],
+        currentAnnotationCount: 0,
+      });
+
+      assert.equal(getSelectionState().selectedTab, uiConstants.TAB_NOTES);
+    });
+
+    it('should not select the page notes tab if there were previously annotations in the store', () => {
+      store.dispatch({
+        type: 'ADD_ANNOTATIONS',
+        annotations: [fixtures.oldPageNote(), fixtures.oldPageNote()],
+        currentAnnotationCount: 4,
+      });
+
+      assert.equal(
+        getSelectionState().selectedTab,
+        uiConstants.TAB_ANNOTATIONS
+      );
+    });
+
+    it('should not select the page notes tab if there are non-page-note annotations at the top level', () => {
+      store.dispatch({
+        type: 'ADD_ANNOTATIONS',
+        annotations: [
+          fixtures.oldPageNote(),
+          fixtures.oldPageNote(),
+          fixtures.oldHighlight(),
+        ],
+        currentAnnotationCount: 0,
+      });
+
+      assert.equal(
+        getSelectionState().selectedTab,
+        uiConstants.TAB_ANNOTATIONS
+      );
+    });
+  });
 });