selectors [nfc]: Rename some variables, mostly for clarity.

... but also to simplify further refactoring.

src/pm-conversations/pmConversationsSelectors.js

@@ -18,30 +18,26 @@ export const getRecentConversations: Selector<PmConversationData[]> = createSele
     unreadPms: { [number]: number },
     unreadHuddles: { [string]: number },
   ): PmConversationData[] => {
-    const recipients = messages.map(msg => ({
+    const items = messages.map(msg => ({
       ids: pmUnreadsKeyFromMessage(msg, ownUser.user_id),
-      emails: normalizeRecipientsSansMe(msg.display_recipient, ownUser.email),
+      recipients: normalizeRecipientsSansMe(msg.display_recipient, ownUser.email),
       msgId: msg.id,
     }));
 
-    const latestByRecipient = new Map();
-    recipients.forEach(recipient => {
-      const prev = latestByRecipient.get(recipient.emails);
-      if (!prev || recipient.msgId > prev.msgId) {
-        latestByRecipient.set(recipient.emails, {
-          ids: recipient.ids,
-          recipients: recipient.emails,
-          msgId: recipient.msgId,
-        });
+    const latestByRecipients = new Map();
+    items.forEach(item => {
+      const prev = latestByRecipients.get(item.recipients);
+      if (!prev || item.msgId > prev.msgId) {
+        latestByRecipients.set(item.recipients, item);
       }
     });
 
-    const sortedByMostRecent = Array.from(latestByRecipient.values()).sort(
+    const sortedByMostRecent = Array.from(latestByRecipients.values()).sort(
       (a, b) => +b.msgId - +a.msgId,
     );
 
-    return sortedByMostRecent.map(recipient => ({
-      ...recipient,
+    return sortedByMostRecent.map(conversation => ({
+      ...conversation,
       unread:
         // This business of looking in one place and then the other is kind
         // of messy.  Fortunately it always works, because the key spaces
@@ -50,7 +46,7 @@ export const getRecentConversations: Selector<PmConversationData[]> = createSele
         /* $FlowFixMe: The keys of unreadPms are logically numbers, but because it's an object they
          end up converted to strings, so this access with string keys works.  We should probably use
          a Map for this and similar maps. */
-        unreadPms[recipient.ids] || unreadHuddles[recipient.ids],
+        unreadPms[conversation.ids] || unreadHuddles[conversation.ids],
     }));
   },
 );