Typewriter // MixedAlnum: Fix edge cases with lowerCamelCase.

Author: ShikiSuen

Packages/vChewing_Typewriter/Sources/Typewriter/Typewriter/Typewriter_MixedAlphanumerical.swift

@@ -138,10 +138,21 @@ public struct MixedAlphanumericalTypewriter<Handler: InputHandlerProtocol>: Type
         // BPMF 失敗，恢復 buffer 並繼續嘗試 auto-split
         handler.mixedAlphanumericalBuffer = originalMixedBuffer
       }
+      // 若 buffer 含多個大寫字母且有小寫字母（camelCase/縮寫，如 cOS、macOS），
+      // 即使 shouldPreferASCIIWordOnSpace 為 true，仍應嘗試 auto-split，
+      // 以支援「cOS + 注音」這類混輸。
+      // 條件：≥2 個大寫 + ≥1 個小寫，可區分於簡單首字大寫詞（Hello、Mac）或全大寫詞（HELLO）。
+      let bufferHasMultipleUppercaseAndLowercase: Bool = {
+        let buffer = handler.mixedAlphanumericalBuffer
+        let hasLower = buffer.range(of: "[a-z]", options: .regularExpression) != nil
+        let ucCount = buffer.unicodeScalars.filter { "A"..."Z" ~= $0 }.count
+        return hasLower && ucCount >= 2
+      }()
       // 當 buffer 較長（>= 5 字元）時，即使 shouldPreferASCIIWordOnSpace 為 true
       // 也嘗試 auto-split，以支援 hello你好 等長 ASCII prefix 的混輸情境。
       if !shouldPreferASCIIWordOnSpace || twoCharPrefixIsPhonetic
-        || handler.mixedAlphanumericalBuffer.count >= 5 {
+        || handler.mixedAlphanumericalBuffer.count >= 5
+        || bufferHasMultipleUppercaseAndLowercase {
         // 先嘗試無 word-like 限制的 auto-split（fallback），以正確保留常見雙字母前綴（如 ai）。
         // 若 fallback 失敗，再嘗試 word-like 限制，以支援 hello你好 類型混輸。
         if tryAutoSplitASCIIAndPhoneticSuffix(
@@ -633,6 +644,13 @@ public struct MixedAlphanumericalTypewriter<Handler: InputHandlerProtocol>: Type
       if trialComposer.hasIntonation(withNothingElse: true) { return nil }
     }
 
+    // 後綴若包含大寫字母，不得被視為注音後綴。
+    // 大寫字母只能透過 Shift 鍵入，在 mixed mode 下明確代表 ASCII 意圖。
+    // 若允許大寫字母進入注音 composer（因 receiveKey 對大小寫不敏感），
+    // 則「macOS 」這類 camelCase 輸入會被誤拆為 ASCII 前綴 + 注音後綴。
+    let suffixHasUppercase = suffixText.range(of: "[A-Z]", options: .regularExpression) != nil
+    guard !suffixHasUppercase else { return nil }
+
     trialComposer.clear()
     // 在評估 mixed 輸入時，暫時停用自動糾正。否則 auto-correct 會讓不同的 suffix
     // 坍縮到同一個 reading key（例如「zj/4」被糾正為「ㄈㄥˋ」而與「z/4」相同），

Packages/vChewing_Typewriter/Tests/TypewriterTests/InputHandlerTests_Cases4.swift

@@ -31,7 +31,7 @@ extension InputHandlerTests {
   /// - Parameters:
   ///   - thePrefix: 要測試的前綴。
   /// - Warning: This unit test case is not designed for dynamic phonabet layouts.
-  @Test(arguments: ["", "ai", "AI", "hello", "Hello"])
+  @Test(arguments: ["", "ai", "ello", "cOS"])
   func test_IH400_MixedAlnumKanjiInputTest_Izanami(
     _ thePrefix: String
   ) throws {
@@ -1163,6 +1163,69 @@ extension InputHandlerTests {
     #expect(testHandler.committableDisplayText(sansReading: true) == "這", "5k4 應為 ㄓㄜˋ=這")
   }
 
+  // MARK: — camelCase 後綴不得被誤判為注音
+
+  /// camelCase 英文詞中大寫字母不得被 auto-split 誤判為注音後綴。
+  /// 此測試鎖住 bug：`macOS ` 被誤拆成 `ma` + 注音後綴 `OS`。
+  @Test
+  func test_IH429_MixedCamelCaseSuffixNotTreatedAsPhonetic() throws {
+    let (testHandler, testSession) = try prepareMixedModeHandler()
+
+    // macOS：大寫後綴 "OS" 不得被當作注音
+    typeSentence("macOS ")
+    #expect(testSession.recentCommissions.joined() == "macOS ")
+    #expect(testHandler.mixedAlphanumericalBuffer.isEmpty)
+    #expect(testHandler.composer.isEmpty)
+
+    testHandler.clear()
+    testSession.recentCommissions.removeAll()
+
+    // This：大寫開頭的純 ASCII 單字應維持完整
+    typeSentence("This ")
+    #expect(testSession.recentCommissions.joined() == "This ")
+    #expect(testHandler.mixedAlphanumericalBuffer.isEmpty)
+    #expect(testHandler.composer.isEmpty)
+  }
+
+  // MARK: — CamelCase 縮寫作為 ASCII 前綴 + 注音後綴
+
+  /// camelCase 縮寫（如 cOS / macOS）作為 ASCII 前綴時，
+  /// 後續注音輸入應正確拆分，而非整段被當作 ASCII 提交。
+  @Test
+  func test_IH430_MixedCamelCasePrefixWithPhoneticSuffix() throws {
+    let (testHandler, testSession) = try prepareMixedModeHandler()
+    testHandler.currentLM.setOptions { cfg in
+      cfg.alwaysSupplyETenDOSUnigrams = true
+    }
+
+    // cOS + ㄆ（Dachen26 鍵序 q ）
+    typeSentence("cOSq ")
+    let allCommissions = testSession.recentCommissions.joined()
+    #expect(allCommissions.contains("cOS"), "cOS prefix should be committed as ASCII")
+    #expect(testHandler.assembler.length == 1, "Assembler should have one reading")
+    #expect(testHandler.assembler.actualKeys.last == "ㄆ", "Reading should be ㄆ")
+
+    testHandler.clear()
+    testSession.resetInputHandler(forceComposerCleanup: true)
+
+    // macOS + ㄆ（Dachen26 鍵序 q ）
+    typeSentence("macOSq ")
+    let allCommissions2 = testSession.recentCommissions.joined()
+    #expect(allCommissions2.contains("macOS"), "macOS prefix should be committed as ASCII")
+    #expect(testHandler.assembler.length == 1, "Assembler should have one reading")
+    #expect(testHandler.assembler.actualKeys.last == "ㄆ", "Reading should be ㄆ")
+
+    testHandler.clear()
+    testSession.resetInputHandler(forceComposerCleanup: true)
+
+    // cOS + ㄇㄛ（Dachen26 鍵序 ai ）
+    typeSentence("cOSai ")
+    let allCommissions3 = testSession.recentCommissions.joined()
+    #expect(allCommissions3.contains("cOS"), "cOS prefix should be committed as ASCII")
+    #expect(testHandler.assembler.length == 1, "Assembler should have one reading")
+    #expect(testHandler.assembler.actualKeys.last == "ㄇㄛ", "Reading should be ㄇㄛ")
+  }
+
   // MARK: - Fileprivate Helpers.
 
   fileprivate func prepareMixedModeHandler() throws -> (handler: MockInputHandler, session: MockSession) {