diff --git a/libra/src/command/diff.rs b/libra/src/command/diff.rs
index 6ca6e0844..20ff119bf 100644
--- a/libra/src/command/diff.rs
+++ b/libra/src/command/diff.rs
@@ -231,6 +231,27 @@ pub async fn diff(
             String::from_utf8(new_content),
         ) {
             (Ok(old_text), Ok(new_text)) => {
+                let (old_prefix, new_prefix) = if old_text.is_empty() {
+                    // New file
+                    (
+                        "/dev/null".to_string(),
+                        format!("b/{}", file_display(&file, new_hash, new_type)),
+                    )
+                } else if new_text.is_empty() {
+                    // Remove file
+                    (
+                        format!("a/{}", file_display(&file, old_hash, old_type)),
+                        "/dev/null".to_string(),
+                    )
+                } else {
+                    // Update file
+                    (
+                        format!("a/{}", file_display(&file, old_hash, old_type)),
+                        format!("b/{}", file_display(&file, new_hash, new_type)),
+                    )
+                };
+                writeln!(w, "--- {}", old_prefix).unwrap();
+                writeln!(w, "+++ {}", new_prefix).unwrap();
                 imara_diff_result(&old_text, &new_text, w);
             }
             _ => {
diff --git a/moon/packages/types/generated.ts b/moon/packages/types/generated.ts
index 76cfc0b6e..862243ccd 100644
--- a/moon/packages/types/generated.ts
+++ b/moon/packages/types/generated.ts
@@ -3233,8 +3233,7 @@ export type MegaConversation = {
   id: number
   /** @format int64 */
   updated_at: number
-  /** @format int64 */
-  user_id: number
+  user_id: string
 }
 
 export enum MergeStatusEnum {