Refactor indent level className

src/core/client/stream/tabs/comments/components/Indent.tsx

@@ -10,17 +10,30 @@ export interface IndentProps {
   children: React.ReactNode;
 }
 
+const levels = [
+  styles.level1,
+  styles.level2,
+  styles.level3,
+  styles.level4,
+  styles.level5,
+  styles.level6,
+];
+
+function getLevelClassName(level?: number) {
+  if (!level) {
+    return "";
+  }
+  if (level - 1 > levels.length) {
+    throw new Error(`Indent level ${level} does not exist`);
+  }
+  return levels[level - 1];
+}
+
 const Indent: StatelessComponent<IndentProps> = props => {
   return (
     <div className={cn(props.className, styles.root)}>
       <div
-        className={cn({
-          [styles.level1]: props.level === 1,
-          [styles.level2]: props.level === 2,
-          [styles.level3]: props.level === 3,
-          [styles.level4]: props.level === 4,
-          [styles.level5]: props.level === 5,
-          [styles.level6]: props.level === 6,
+        className={cn(getLevelClassName(props.level), {
           [styles.noBorder]: props.noBorder,
         })}
       >