create db.is_media_group_exists

src/db/mod.rs

@@ -228,6 +228,23 @@ impl DB {
         Ok(media_items)
     }
 
+    pub async fn is_media_group_exists(
+        &mut self,
+        media_group: &str,
+    ) -> Result<bool, Box<dyn std::error::Error>> {
+        use self::schema::media::dsl::*;
+        let conn = &mut self.pool.get().await.unwrap();
+
+        let is_exists = media
+            .filter(media_group_id.eq(media_group))
+            .count()
+            .get_result::<i64>(conn)
+            .await?
+            > 0;
+
+        Ok(is_exists)
+    }
+
     pub async fn drop_media(&mut self, literal: &str) -> Result<usize, Box<dyn std::error::Error>> {
         use self::schema::media::dsl::*;
         let conn = &mut self.pool.get().await.unwrap();

src/db/tests.rs

@@ -89,3 +89,31 @@ async fn test_drop_media() {
     // Clean up after test
     let result = db.drop_media("test_drop_media_literal").await.unwrap();
 }
+
+#[tokio::test]
+async fn test_is_media_group_exists() {
+    let mut db = setup_db().await;
+
+    let media_group = "test_media_group";
+
+    let exists = db.is_media_group_exists(media_group).await.unwrap();
+    assert!(!exists);
+
+    let _ = db
+        .add_media(
+            "test_media_group_literal",
+            "photo",
+            "file_id_1",
+            Some(media_group),
+        )
+        .await
+        .unwrap();
+
+    let exists = db.is_media_group_exists(media_group).await.unwrap();
+    assert!(exists);
+
+    let _ = db.drop_media("test_media_group_literal").await.unwrap();
+
+    let exists = db.is_media_group_exists(media_group).await.unwrap();
+    assert!(!exists);
+}