Refactor TimelineContentFilter to use Snapshot struct

Introduces a Snapshot struct in TimelineContentFilter to capture filter state, and updates TimelineDatasource to use this snapshot for filtering. Refactors related methods and tests to use the new snapshot-based approach, improving clarity and thread safety.

Author: Dimillian

Packages/Timeline/Sources/Timeline/TimelineContentFilter.swift

@@ -3,6 +3,25 @@ import SwiftUI
 
 @MainActor
 @Observable public class TimelineContentFilter {
+  public struct Snapshot: Sendable {
+    public let showBoosts: Bool
+    public let showReplies: Bool
+    public let showThreads: Bool
+    public let showQuotePosts: Bool
+
+    public init(
+      showBoosts: Bool,
+      showReplies: Bool,
+      showThreads: Bool,
+      showQuotePosts: Bool
+    ) {
+      self.showBoosts = showBoosts
+      self.showReplies = showReplies
+      self.showThreads = showThreads
+      self.showQuotePosts = showQuotePosts
+    }
+  }
+
   class Storage {
     @AppStorage("timeline_show_boosts") var showBoosts: Bool = true
     @AppStorage("timeline_show_replies") var showReplies: Bool = true
@@ -43,4 +62,13 @@ import SwiftUI
     showThreads = storage.showThreads
     showQuotePosts = storage.showQuotePosts
   }
+
+  public func snapshot() -> Snapshot {
+    Snapshot(
+      showBoosts: showBoosts,
+      showReplies: showReplies,
+      showThreads: showThreads,
+      showQuotePosts: showQuotePosts
+    )
+  }
 }

Packages/Timeline/Sources/Timeline/actors/TimelineDatasource.swift

@@ -24,10 +24,11 @@ actor TimelineDatasource {
 
   func getFiltered() async -> [Status] {
     let contentFilter = await TimelineContentFilter.shared
+    let snapshot = await contentFilter.snapshot()
     var filtered: [Status] = []
     for item in items {
       guard case .status(let status) = item else { continue }
-      if await shouldShowStatus(status, filter: contentFilter) {
+      if shouldShowStatus(status, filter: snapshot) {
         filtered.append(status)
       }
     }
@@ -36,20 +37,32 @@ actor TimelineDatasource {
 
   func getFilteredItems() async -> [TimelineItem] {
     let contentFilter = await TimelineContentFilter.shared
+    let snapshot = await contentFilter.snapshot()
     var filtered: [TimelineItem] = []
     for item in items {
       switch item {
       case .gap:
         filtered.append(item)
       case .status(let status):
-        if await shouldShowStatus(status, filter: contentFilter) {
+        if shouldShowStatus(status, filter: snapshot) {
           filtered.append(item)
         }
       }
     }
     return filtered
   }
 
+  func getFiltered(using snapshot: TimelineContentFilter.Snapshot) -> [Status] {
+    var filtered: [Status] = []
+    for item in items {
+      guard case .status(let status) = item else { continue }
+      if shouldShowStatus(status, filter: snapshot) {
+        filtered.append(status)
+      }
+    }
+    return filtered
+  }
+
   func count() -> Int {
     items.count
   }
@@ -155,11 +168,11 @@ actor TimelineDatasource {
 
   // MARK: - Private Helpers
 
-  private func shouldShowStatus(_ status: Status, filter: TimelineContentFilter) async -> Bool {
-    let showReplies = await filter.showReplies
-    let showBoosts = await filter.showBoosts
-    let showThreads = await filter.showThreads
-    let showQuotePosts = await filter.showQuotePosts
+  private func shouldShowStatus(_ status: Status, filter: TimelineContentFilter.Snapshot) -> Bool {
+    let showReplies = filter.showReplies
+    let showBoosts = filter.showBoosts
+    let showThreads = filter.showThreads
+    let showQuotePosts = filter.showQuotePosts
     let hasQuote = status.quote?.quotedStatusId != nil
       || status.quote?.quotedStatus != nil
       || status.reblog?.quote?.quotedStatusId != nil

Packages/Timeline/Tests/TimelineTests/TimelineViewModelTests.swift

@@ -136,12 +136,6 @@ struct Tests {
 
   @Test
   func hideQuotePostsFiltersLegacyAndNativeQuotes() async throws {
-    let contentFilter = TimelineContentFilter.shared
-    contentFilter.showBoosts = true
-    contentFilter.showReplies = true
-    contentFilter.showThreads = true
-    contentFilter.showQuotePosts = false
-
     let normalStatus = makeStatus(id: "normal", hidden: false)
     let legacyQuoteStatus = makeStatus(
       id: "legacy-quote",
@@ -157,7 +151,13 @@ struct Tests {
     let datasource = TimelineDatasource()
     await datasource.set([normalStatus, legacyQuoteStatus, nativeQuoteStatus])
 
-    let filtered = await datasource.getFiltered()
+    let snapshot = TimelineContentFilter.Snapshot(
+      showBoosts: true,
+      showReplies: true,
+      showThreads: true,
+      showQuotePosts: false
+    )
+    let filtered = await datasource.getFiltered(using: snapshot)
     #expect(filtered.map(\.id) == ["normal"])
   }
 }