feat: configurable chat history scrollback

src-tauri/src/types.rs

@@ -573,6 +573,11 @@ pub(crate) struct AppSettings {
         rename = "showMessageFilePath"
     )]
     pub(crate) show_message_file_path: bool,
+    #[serde(
+        default = "default_chat_history_scrollback_items",
+        rename = "chatHistoryScrollbackItems"
+    )]
+    pub(crate) chat_history_scrollback_items: Option<u32>,
     #[serde(default, rename = "threadTitleAutogenerationEnabled")]
     pub(crate) thread_title_autogeneration_enabled: bool,
     #[serde(default = "default_ui_font_family", rename = "uiFontFamily")]
@@ -760,6 +765,10 @@ fn default_show_message_file_path() -> bool {
     true
 }
 
+fn default_chat_history_scrollback_items() -> Option<u32> {
+    Some(200)
+}
+
 fn default_ui_font_family() -> String {
     "system-ui, -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, \"Helvetica Neue\", Arial, sans-serif".to_string()
 }
@@ -1187,6 +1196,7 @@ impl Default for AppSettings {
             theme: default_theme(),
             usage_show_remaining: default_usage_show_remaining(),
             show_message_file_path: default_show_message_file_path(),
+            chat_history_scrollback_items: default_chat_history_scrollback_items(),
             thread_title_autogeneration_enabled: false,
             ui_font_family: default_ui_font_family(),
             code_font_family: default_code_font_family(),
@@ -1350,6 +1360,7 @@ mod tests {
         assert_eq!(settings.theme, "system");
         assert!(!settings.usage_show_remaining);
         assert!(settings.show_message_file_path);
+        assert_eq!(settings.chat_history_scrollback_items, Some(200));
         assert!(!settings.thread_title_autogeneration_enabled);
         assert!(settings.ui_font_family.contains("system-ui"));
         assert!(settings.code_font_family.contains("ui-monospace"));

src/App.tsx

@@ -577,6 +577,9 @@ function MainApp() {
     reviewDeliveryMode: appSettings.reviewDeliveryMode,
     steerEnabled: appSettings.steerEnabled,
     threadTitleAutogenerationEnabled: appSettings.threadTitleAutogenerationEnabled,
+    chatHistoryScrollbackItems: appSettingsLoading
+      ? null
+      : appSettings.chatHistoryScrollbackItems,
     customPrompts: prompts,
     onMessageActivity: handleThreadMessageActivity,
     threadSortKey: threadListSortKey,

src/features/settings/components/SettingsView.test.tsx

@@ -73,6 +73,7 @@ const baseSettings: AppSettings = {
   theme: "system",
   usageShowRemaining: false,
   showMessageFilePath: true,
+  chatHistoryScrollbackItems: 200,
   threadTitleAutogenerationEnabled: false,
   uiFontFamily:
     'system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif',

src/features/settings/components/sections/SettingsDisplaySection.test.tsx

@@ -1,10 +1,13 @@
 // @vitest-environment jsdom
-import { fireEvent, render, screen, within } from "@testing-library/react";
-import { describe, expect, it, vi } from "vitest";
+import { cleanup, fireEvent, render, screen, within } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import type { AppSettings } from "@/types";
 import { SettingsDisplaySection } from "./SettingsDisplaySection";
 
 describe("SettingsDisplaySection", () => {
+  afterEach(() => {
+    cleanup();
+  });
   it("toggles auto-generated thread titles", () => {
     const onUpdateAppSettings = vi.fn(async () => {});
 
@@ -58,4 +61,286 @@ describe("SettingsDisplaySection", () => {
       expect.objectContaining({ threadTitleAutogenerationEnabled: true }),
     );
   });
+  it("toggles unlimited chat history", () => {
+    const onUpdateAppSettings = vi.fn(async () => {});
+
+    render(
+      <SettingsDisplaySection
+        appSettings={
+          ({
+            theme: "system",
+            usageShowRemaining: false,
+            showMessageFilePath: true,
+            chatHistoryScrollbackItems: 200,
+            threadTitleAutogenerationEnabled: false,
+            uiFontFamily: "",
+            codeFontFamily: "",
+            codeFontSize: 11,
+            notificationSoundsEnabled: true,
+            systemNotificationsEnabled: true,
+          } as unknown) as AppSettings
+        }
+        reduceTransparency={false}
+        scaleShortcutTitle=""
+        scaleShortcutText=""
+        scaleDraft="100%"
+        uiFontDraft=""
+        codeFontDraft=""
+        codeFontSizeDraft={11}
+        onUpdateAppSettings={onUpdateAppSettings}
+        onToggleTransparency={vi.fn()}
+        onSetScaleDraft={vi.fn() as any}
+        onCommitScale={vi.fn(async () => {})}
+        onResetScale={vi.fn(async () => {})}
+        onSetUiFontDraft={vi.fn() as any}
+        onCommitUiFont={vi.fn(async () => {})}
+        onSetCodeFontDraft={vi.fn() as any}
+        onCommitCodeFont={vi.fn(async () => {})}
+        onSetCodeFontSizeDraft={vi.fn() as any}
+        onCommitCodeFontSize={vi.fn(async () => {})}
+        onTestNotificationSound={vi.fn()}
+        onTestSystemNotification={vi.fn()}
+      />,
+    );
+
+    const row = screen.getByText("Unlimited chat history").closest(".settings-toggle-row");
+    expect(row).toBeTruthy();
+    const button = within(row as HTMLElement).getByRole("button");
+
+    fireEvent.click(button);
+
+    expect(onUpdateAppSettings).toHaveBeenCalledWith(
+      expect.objectContaining({ chatHistoryScrollbackItems: null }),
+    );
+  });
+
+  it("disables scrollback controls when unlimited chat history is enabled", () => {
+    const onUpdateAppSettings = vi.fn(async () => {});
+
+    render(
+      <SettingsDisplaySection
+        appSettings={
+          ({
+            theme: "system",
+            usageShowRemaining: false,
+            showMessageFilePath: true,
+            chatHistoryScrollbackItems: null,
+            threadTitleAutogenerationEnabled: false,
+            uiFontFamily: "",
+            codeFontFamily: "",
+            codeFontSize: 11,
+            notificationSoundsEnabled: true,
+            systemNotificationsEnabled: true,
+          } as unknown) as AppSettings
+        }
+        reduceTransparency={false}
+        scaleShortcutTitle=""
+        scaleShortcutText=""
+        scaleDraft="100%"
+        uiFontDraft=""
+        codeFontDraft=""
+        codeFontSizeDraft={11}
+        onUpdateAppSettings={onUpdateAppSettings}
+        onToggleTransparency={vi.fn()}
+        onSetScaleDraft={vi.fn() as any}
+        onCommitScale={vi.fn(async () => {})}
+        onResetScale={vi.fn(async () => {})}
+        onSetUiFontDraft={vi.fn() as any}
+        onCommitUiFont={vi.fn(async () => {})}
+        onSetCodeFontDraft={vi.fn() as any}
+        onCommitCodeFont={vi.fn(async () => {})}
+        onSetCodeFontSizeDraft={vi.fn() as any}
+        onCommitCodeFontSize={vi.fn(async () => {})}
+        onTestNotificationSound={vi.fn()}
+        onTestSystemNotification={vi.fn()}
+      />,
+    );
+
+    const presetSelect = screen.getByLabelText("Scrollback preset");
+    expect((presetSelect as HTMLSelectElement).disabled).toBe(true);
+
+    const maxItemsInput = screen.getByLabelText("Max items per thread");
+    expect((maxItemsInput as HTMLInputElement).disabled).toBe(true);
+
+    const maxItemsRow = maxItemsInput.closest(".settings-field-row");
+    expect(maxItemsRow).toBeTruthy();
+    const resetButton = within(maxItemsRow as HTMLElement).getByRole("button", {
+      name: "Reset",
+    });
+    expect((resetButton as HTMLButtonElement).disabled).toBe(true);
+
+    fireEvent.change(presetSelect, { target: { value: "1000" } });
+    expect(onUpdateAppSettings).not.toHaveBeenCalled();
+  });
+
+  it("applies scrollback presets", () => {
+    const onUpdateAppSettings = vi.fn(async () => {});
+
+    render(
+      <SettingsDisplaySection
+        appSettings={
+          ({
+            theme: "system",
+            usageShowRemaining: false,
+            showMessageFilePath: true,
+            chatHistoryScrollbackItems: 200,
+            threadTitleAutogenerationEnabled: false,
+            uiFontFamily: "",
+            codeFontFamily: "",
+            codeFontSize: 11,
+            notificationSoundsEnabled: true,
+            systemNotificationsEnabled: true,
+          } as unknown) as AppSettings
+        }
+        reduceTransparency={false}
+        scaleShortcutTitle=""
+        scaleShortcutText=""
+        scaleDraft="100%"
+        uiFontDraft=""
+        codeFontDraft=""
+        codeFontSizeDraft={11}
+        onUpdateAppSettings={onUpdateAppSettings}
+        onToggleTransparency={vi.fn()}
+        onSetScaleDraft={vi.fn() as any}
+        onCommitScale={vi.fn(async () => {})}
+        onResetScale={vi.fn(async () => {})}
+        onSetUiFontDraft={vi.fn() as any}
+        onCommitUiFont={vi.fn(async () => {})}
+        onSetCodeFontDraft={vi.fn() as any}
+        onCommitCodeFont={vi.fn(async () => {})}
+        onSetCodeFontSizeDraft={vi.fn() as any}
+        onCommitCodeFontSize={vi.fn(async () => {})}
+        onTestNotificationSound={vi.fn()}
+        onTestSystemNotification={vi.fn()}
+      />,
+    );
+
+    const select = screen.getByLabelText("Scrollback preset");
+    fireEvent.change(select, { target: { value: "1000" } });
+
+    expect(onUpdateAppSettings).toHaveBeenCalledWith(
+      expect.objectContaining({ chatHistoryScrollbackItems: 1000 }),
+    );
+  });
+
+  it("does not persist scrollback draft on blur when toggling unlimited", () => {
+    const onUpdateAppSettings = vi.fn(async () => {});
+
+    render(
+      <SettingsDisplaySection
+        appSettings={
+          ({
+            theme: "system",
+            usageShowRemaining: false,
+            showMessageFilePath: true,
+            chatHistoryScrollbackItems: 200,
+            threadTitleAutogenerationEnabled: false,
+            uiFontFamily: "",
+            codeFontFamily: "",
+            codeFontSize: 11,
+            notificationSoundsEnabled: true,
+            systemNotificationsEnabled: true,
+          } as unknown) as AppSettings
+        }
+        reduceTransparency={false}
+        scaleShortcutTitle=""
+        scaleShortcutText=""
+        scaleDraft="100%"
+        uiFontDraft=""
+        codeFontDraft=""
+        codeFontSizeDraft={11}
+        onUpdateAppSettings={onUpdateAppSettings}
+        onToggleTransparency={vi.fn()}
+        onSetScaleDraft={vi.fn() as any}
+        onCommitScale={vi.fn(async () => {})}
+        onResetScale={vi.fn(async () => {})}
+        onSetUiFontDraft={vi.fn() as any}
+        onCommitUiFont={vi.fn(async () => {})}
+        onSetCodeFontDraft={vi.fn() as any}
+        onCommitCodeFont={vi.fn(async () => {})}
+        onSetCodeFontSizeDraft={vi.fn() as any}
+        onCommitCodeFontSize={vi.fn(async () => {})}
+        onTestNotificationSound={vi.fn()}
+        onTestSystemNotification={vi.fn()}
+      />,
+    );
+
+    const maxItemsInput = screen.getByLabelText("Max items per thread");
+    fireEvent.change(maxItemsInput, { target: { value: "50" } });
+
+    const unlimitedRow = screen
+      .getByText("Unlimited chat history")
+      .closest(".settings-toggle-row");
+    expect(unlimitedRow).toBeTruthy();
+    const unlimitedButton = within(unlimitedRow as HTMLElement).getByRole("button");
+
+    fireEvent.blur(maxItemsInput, { relatedTarget: unlimitedButton });
+    fireEvent.click(unlimitedButton);
+
+    expect(onUpdateAppSettings).toHaveBeenCalledTimes(1);
+    expect(onUpdateAppSettings).toHaveBeenCalledWith(
+      expect.objectContaining({ chatHistoryScrollbackItems: null }),
+    );
+  });
+
+  it("does not persist scrollback draft on blur when clicking Reset", () => {
+    const onUpdateAppSettings = vi.fn(async () => {});
+
+    render(
+      <SettingsDisplaySection
+        appSettings={
+          ({
+            theme: "system",
+            usageShowRemaining: false,
+            showMessageFilePath: true,
+            chatHistoryScrollbackItems: 200,
+            threadTitleAutogenerationEnabled: false,
+            uiFontFamily: "",
+            codeFontFamily: "",
+            codeFontSize: 11,
+            notificationSoundsEnabled: true,
+            systemNotificationsEnabled: true,
+          } as unknown) as AppSettings
+        }
+        reduceTransparency={false}
+        scaleShortcutTitle=""
+        scaleShortcutText=""
+        scaleDraft="100%"
+        uiFontDraft=""
+        codeFontDraft=""
+        codeFontSizeDraft={11}
+        onUpdateAppSettings={onUpdateAppSettings}
+        onToggleTransparency={vi.fn()}
+        onSetScaleDraft={vi.fn() as any}
+        onCommitScale={vi.fn(async () => {})}
+        onResetScale={vi.fn(async () => {})}
+        onSetUiFontDraft={vi.fn() as any}
+        onCommitUiFont={vi.fn(async () => {})}
+        onSetCodeFontDraft={vi.fn() as any}
+        onCommitCodeFont={vi.fn(async () => {})}
+        onSetCodeFontSizeDraft={vi.fn() as any}
+        onCommitCodeFontSize={vi.fn(async () => {})}
+        onTestNotificationSound={vi.fn()}
+        onTestSystemNotification={vi.fn()}
+      />,
+    );
+
+    const maxItemsInput = screen.getByLabelText("Max items per thread");
+    fireEvent.change(maxItemsInput, { target: { value: "50" } });
+
+    const maxItemsRow = maxItemsInput.closest(".settings-field-row");
+    expect(maxItemsRow).toBeTruthy();
+    const resetButton = within(maxItemsRow as HTMLElement).getByRole("button", {
+      name: "Reset",
+    });
+
+    fireEvent.blur(maxItemsInput, { relatedTarget: resetButton });
+    fireEvent.click(resetButton);
+
+    expect(onUpdateAppSettings).toHaveBeenCalledTimes(1);
+    expect(onUpdateAppSettings).toHaveBeenCalledWith(
+      expect.objectContaining({ chatHistoryScrollbackItems: 200 }),
+    );
+  });
+
 });