feat: Improve theme not found handling

Modify  to return a boolean instead of throwing an error when a theme is not found. Update CLI startup and  hook to handle the boolean return value for more graceful error handling.

3 files changed, 23 insertions, 59 deletions

diff --git a/packages/cli/src/gemini.ts b/packages/cli/src/gemini.ts
index 32e34c20..1f48a99b 100644
--- a/packages/cli/src/gemini.ts
+++ b/packages/cli/src/gemini.ts
@@ -24,23 +24,10 @@ async function main() {
   const settings = loadSettings(process.cwd());
   const config = await loadCliConfig(settings.merged);
   if (settings.merged.theme) {
-    try {
-      themeManager.setActiveTheme(settings.merged.theme);
-    } catch (error: unknown) {
+    if (!themeManager.setActiveTheme(settings.merged.theme)) {
       // If the theme is not found during initial load, log a warning and continue.
       // The useThemeCommand hook in App.tsx will handle opening the dialog.
-      if (
-        error instanceof Error &&
-        error.message.includes('Theme') &&
-        error.message.includes('not found')
-      ) {
-        console.warn(
-          `Warning: ${error instanceof Error ? error.message : String(error)}`,
-        );
-      } else {
-        // Re-throw other errors to be caught by the main catch block
-        throw error;
-      }
+      console.warn(`Warning: Theme "${settings.merged.theme}" not found.`);
     }
   }
 
diff --git a/packages/cli/src/ui/hooks/useThemeCommand.ts b/packages/cli/src/ui/hooks/useThemeCommand.ts
index b1ae170f..d8b0ef6b 100644
--- a/packages/cli/src/ui/hooks/useThemeCommand.ts
+++ b/packages/cli/src/ui/hooks/useThemeCommand.ts
@@ -32,28 +32,12 @@ export const useThemeCommand = (
 
   // Apply initial theme on component mount
   useEffect(() => {
-    try {
-      themeManager.setActiveTheme(effectiveTheme);
-      setThemeError(null); // Clear any previous theme error on success
-    } catch (error: unknown) {
+    if (!themeManager.setActiveTheme(effectiveTheme)) {
       // If theme is not found during initial load, open the theme selection dialog and set error message
-      if (
-        error instanceof Error &&
-        error.message.includes('Theme') &&
-        error.message.includes('not found')
-      ) {
-        setIsThemeDialogOpen(true);
-        setThemeError(
-          `Error: ${error instanceof Error ? error.message : String(error)}`,
-        );
-      } else {
-        console.error(
-          `Error setting initial theme: ${error instanceof Error ? error.message : String(error)}`,
-        );
-        setThemeError(
-          `Error setting initial theme: ${error instanceof Error ? error.message : String(error)}`,
-        );
-      }
+      setIsThemeDialogOpen(true);
+      setThemeError(`Theme "${effectiveTheme}" not found.`);
+    } else {
+      setThemeError(null); // Clear any previous theme error on success
     }
   }, [effectiveTheme, setThemeError]); // Re-run if effectiveTheme or setThemeError changes
 
@@ -63,29 +47,13 @@ export const useThemeCommand = (
 
   const applyTheme = useCallback(
     (themeName: string | undefined) => {
-      try {
-        themeManager.setActiveTheme(themeName);
+      if (!themeManager.setActiveTheme(themeName)) {
+        // If theme is not found, open the theme selection dialog and set error message
+        setIsThemeDialogOpen(true);
+        setThemeError(`Theme "${themeName}" not found.`);
+      } else {
         setForceRender((v) => v + 1); // Trigger potential re-render
         setThemeError(null); // Clear any previous theme error on success
-      } catch (error: unknown) {
-        // If theme is not found, open the theme selection dialog and set error message
-        if (
-          error instanceof Error &&
-          error.message.includes('Theme') &&
-          error.message.includes('not found')
-        ) {
-          setIsThemeDialogOpen(true);
-          setThemeError(
-            `Error: ${error instanceof Error ? error.message : String(error)}`,
-          );
-        } else {
-          console.error(
-            `Error setting theme: ${error instanceof Error ? error.message : String(error)}`,
-          );
-          setThemeError(
-            `Error setting theme: ${error instanceof Error ? error.message : String(error)}`,
-          );
-        }
       }
     },
     [setForceRender, setThemeError],
diff --git a/packages/cli/src/ui/themes/theme-manager.ts b/packages/cli/src/ui/themes/theme-manager.ts
index d1f8df9c..e17fa5b7 100644
--- a/packages/cli/src/ui/themes/theme-manager.ts
+++ b/packages/cli/src/ui/themes/theme-manager.ts
@@ -73,14 +73,23 @@ class ThemeManager {
   /**
    * Sets the active theme.
    * @param themeName The name of the theme to activate.
+   * @returns True if the theme was successfully set, false otherwise.
    */
-  setActiveTheme(themeName: string | undefined): void {
+  setActiveTheme(themeName: string | undefined): boolean {
     const foundTheme = this.findThemeByName(themeName);
 
     if (foundTheme) {
       this.activeTheme = foundTheme;
+      return true;
     } else {
-      throw new Error(`Theme "${themeName}" not found.`);
+      // If themeName is undefined, it means we want to set the default theme.
+      // If findThemeByName returns undefined (e.g. default theme is also not found for some reason)
+      // then this will return false.
+      if (themeName === undefined) {
+        this.activeTheme = DEFAULT_THEME;
+        return true;
+      }
+      return false;
     }
   }