feat(coding-agent): add automatic theme mode (#5874)

packages/coding-agent/test/interactive-mode-status.test.ts

@@ -151,6 +151,13 @@ describe("InteractiveMode.createExtensionUIContext setTheme", () => {
 		const fakeThis: any = {
 			session: { settingsManager },
 			settingsManager,
+			themeController: {
+				setThemeInstance: vi.fn(() => ({ success: true })),
+				setThemeName: vi.fn(() => {
+					fakeThis.ui.requestRender();
+					return { success: true };
+				}),
+			},
 			ui: { requestRender: vi.fn() },
 		};
 
@@ -158,6 +165,7 @@ describe("InteractiveMode.createExtensionUIContext setTheme", () => {
 		const result = uiContext.setTheme("light");
 
 		expect(result.success).toBe(true);
+		expect(fakeThis.themeController.setThemeName).toHaveBeenCalledWith("light");
 		expect(settingsManager.setTheme).toHaveBeenCalledWith("light");
 		expect(currentTheme).toBe("light");
 		expect(fakeThis.ui.requestRender).toHaveBeenCalledTimes(1);
@@ -173,6 +181,10 @@ describe("InteractiveMode.createExtensionUIContext setTheme", () => {
 		const fakeThis: any = {
 			session: { settingsManager },
 			settingsManager,
+			themeController: {
+				setThemeInstance: vi.fn(() => ({ success: true })),
+				setThemeName: vi.fn(() => ({ success: false, error: "Theme not found" })),
+			},
 			ui: { requestRender: vi.fn() },
 		};
 
@@ -180,6 +192,7 @@ describe("InteractiveMode.createExtensionUIContext setTheme", () => {
 		const result = uiContext.setTheme("__missing_theme__");
 
 		expect(result.success).toBe(false);
+		expect(fakeThis.themeController.setThemeName).toHaveBeenCalledWith("__missing_theme__");
 		expect(settingsManager.setTheme).not.toHaveBeenCalled();
 		expect(fakeThis.ui.requestRender).not.toHaveBeenCalled();
 	});

packages/coding-agent/test/settings-manager.test.ts

@@ -198,6 +198,24 @@ describe("SettingsManager", () => {
 		});
 	});
 
+	describe("theme setting", () => {
+		it("stores slash-separated automatic theme settings separately from fixed theme names", async () => {
+			const settingsPath = join(agentDir, "settings.json");
+			writeFileSync(settingsPath, JSON.stringify({ theme: "light/dark" }));
+
+			const manager = SettingsManager.create(projectDir, agentDir);
+
+			expect(manager.getTheme()).toBeUndefined();
+			expect(manager.getThemeSetting()).toBe("light/dark");
+
+			manager.setTheme("solarized-light/tokyo-night");
+			await manager.flush();
+
+			const savedSettings = JSON.parse(readFileSync(settingsPath, "utf-8"));
+			expect(savedSettings.theme).toBe("solarized-light/tokyo-night");
+		});
+	});
+
 	describe("error tracking", () => {
 		it("should collect and clear load errors via drainErrors", () => {
 			const globalSettingsPath = join(agentDir, "settings.json");

packages/coding-agent/test/suite/regressions/5080-signal-shutdown-extension-cleanup.test.ts

@@ -21,6 +21,7 @@ type ShutdownThis = {
 	unregisterSignalHandlers: () => void;
 	runtimeHost: { dispose: () => Promise<void> };
 	ui: { terminal: { drainInput: (ms: number) => Promise<void> } };
+	themeController: { disableAutoSync: () => void };
 	stop: () => void;
 	sessionManager: SessionManager;
 };
@@ -81,6 +82,7 @@ function createContext(order: string[], sessionManager = createSessionManager())
 				}),
 			},
 		},
+		themeController: { disableAutoSync: vi.fn() },
 		stop: vi.fn(() => {
 			order.push("stop");
 		}),

packages/coding-agent/test/suite/regressions/5724-sigterm-signal-exit.test.ts

@@ -13,6 +13,7 @@ type ShutdownThis = {
 	unregisterSignalHandlers: () => void;
 	runtimeHost: { dispose: () => Promise<void> };
 	ui: { terminal: { drainInput: (ms: number) => Promise<void> } };
+	themeController: { disableAutoSync: () => void };
 	stop: () => void;
 };
 
@@ -73,6 +74,7 @@ describe("InteractiveMode SIGTERM shutdown with signal-exit (#5724)", () => {
 					}),
 				},
 			},
+			themeController: { disableAutoSync: vi.fn() },
 			stop: vi.fn(() => {
 				order.push("stop");
 			}),

packages/coding-agent/test/theme-detection.test.ts

@@ -5,6 +5,8 @@ import {
 	detectTerminalBackgroundTheme,
 	getThemeByName,
 	getThemeForRgbColor,
+	parseAutoThemeSetting,
+	resolveThemeSetting,
 } from "../src/modes/interactive/theme/theme.ts";
 
 afterEach(() => {
@@ -119,3 +121,13 @@ describe("theme detection from RGB", () => {
 		expect(getThemeForRgbColor({ r: 250, g: 250, b: 250 })).toBe("light");
 	});
 });
+
+describe("theme setting helpers", () => {
+	it("parses and resolves automatic theme settings", () => {
+		expect(parseAutoThemeSetting("light/dark")).toEqual({ lightTheme: "light", darkTheme: "dark" });
+		expect(resolveThemeSetting("dark", "light")).toBe("dark");
+		expect(resolveThemeSetting("light/dark", "light")).toBe("light");
+		expect(resolveThemeSetting("light/dark", "dark")).toBe("dark");
+		expect(resolveThemeSetting("light/dark/extra", "dark")).toBeUndefined();
+	});
+});