refactor: refactor timeline filtering logic (#1667)

src/routes/_store/computations/timelineComputations.js

@@ -9,6 +9,7 @@ import {
   NOTIFICATION_POLLS,
   NOTIFICATION_MENTIONS
 } from '../../_static/instanceSettings'
+import { createFilterFunction } from '../../_utils/createFilterFunction'
 import { mark, stop } from '../../_utils/marks'
 
 function computeForTimeline (store, key, defaultValue) {
@@ -90,30 +91,6 @@ export function timelineComputations (store) {
   computeNotificationFilter(store, 'timelineNotificationShowMentions', NOTIFICATION_MENTIONS)
   computeNotificationFilter(store, 'timelineNotificationShowPolls', NOTIFICATION_POLLS)
 
-  function createFilterFunction (showReblogs, showReplies, showFollows, showFavs, showMentions, showPolls) {
-    return item => {
-      switch (item.type) {
-        case 'poll':
-          return showPolls
-        case 'favourite':
-          return showFavs
-        case 'reblog':
-          return showReblogs
-        case 'mention':
-          return showMentions
-        case 'follow':
-          return showFollows
-      }
-      if (item.reblogId) {
-        return showReblogs
-      } else if (item.replyId) {
-        return showReplies
-      } else {
-        return true
-      }
-    }
-  }
-
   store.compute(
     'timelineFilterFunction',
     [

src/routes/_utils/createFilterFunction.js

@@ -0,0 +1,32 @@
+// create a function for filtering timeline item summaries
+
+function noFilter () {
+  return true
+}
+
+export function createFilterFunction (showReblogs, showReplies, showFollows, showFavs, showMentions, showPolls) {
+  if (showReblogs && showReplies && showFollows && showFavs && showMentions && showPolls) {
+    return noFilter // fast path for the default setting
+  }
+  return item => {
+    switch (item.type) {
+      case 'poll':
+        return showPolls
+      case 'favourite':
+        return showFavs
+      case 'reblog':
+        return showReblogs
+      case 'mention':
+        return showMentions
+      case 'follow':
+        return showFollows
+    }
+    if (item.reblogId) {
+      return showReblogs
+    } else if (item.replyId) {
+      return showReplies
+    } else {
+      return true
+    }
+  }
+}