feat: blob exists query

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - [2265](https://github.com/FuelLabs/fuel-core/pull/2265): Integrate Block Committer API for DA Block Costs.
 - [2280](https://github.com/FuelLabs/fuel-core/pull/2280): Allow comma separated relayer addresses in cli
 - [2299](https://github.com/FuelLabs/fuel-core/pull/2299): Support blobs in the predicates.
+- [2300](https://github.com/FuelLabs/fuel-core/pull/2300): Added new function to `fuel-core-client` for checking whether a blob exists.
 
 ### Changed
 

crates/client/src/client.rs

@@ -905,6 +905,12 @@ impl FuelClient {
         Ok(blob)
     }
 
+    /// Check whether a blob with ID exists
+    pub async fn blob_exists(&self, id: BlobId) -> io::Result<bool> {
+        let query = schema::blob::BlobExistsQuery::build(BlobByIdArgs { id: id.into() });
+        Ok(self.query(query).await?.blob.is_some())
+    }
+
     /// Retrieve multiple blocks
     pub async fn blocks(
         &self,

crates/client/src/client/schema/blob.rs

@@ -26,3 +26,20 @@ pub struct Blob {
     pub id: BlobId,
     pub bytecode: HexString,
 }
+
+#[derive(cynic::QueryFragment, Clone, Debug)]
+#[cynic(schema_path = "./assets/schema.sdl", graphql_type = "Blob")]
+pub struct BlobIdFragment {
+    pub id: BlobId,
+}
+
+#[derive(cynic::QueryFragment, Clone, Debug)]
+#[cynic(
+    schema_path = "./assets/schema.sdl",
+    graphql_type = "Query",
+    variables = "BlobByIdArgs"
+)]
+pub struct BlobExistsQuery {
+    #[arguments(id: $id)]
+    pub blob: Option<BlobIdFragment>,
+}

tests/tests/blob.rs

@@ -233,6 +233,41 @@ async fn blob__can_be_queried_if_uploaded() {
     assert_eq!(queried_blob.bytecode, bytecode);
 }
 
+#[tokio::test]
+async fn blob__exists_if_uploaded() {
+    // Given
+    let mut ctx = TestContext::new().await;
+    let bytecode: Vec<u8> = [op::ret(RegId::ONE)].into_iter().collect();
+    let (status, blob_id) = ctx.new_blob(bytecode.clone()).await.unwrap();
+    assert!(matches!(status, TransactionStatus::Success { .. }));
+
+    // When
+    let blob_exists = ctx
+        .client
+        .blob_exists(blob_id)
+        .await
+        .expect("blob query failed");
+
+    // Then
+    assert!(blob_exists);
+}
+
+#[tokio::test]
+async fn blob__ask_whether_a_nonexisting_blob_exists() {
+    // Given
+    let ctx = TestContext::new().await;
+
+    // When
+    let blob_exists = ctx
+        .client
+        .blob_exists(Default::default())
+        .await
+        .expect("blob query failed");
+
+    // Then
+    assert!(!blob_exists);
+}
+
 #[tokio::test]
 async fn predicate_can_load_blob() {
     let blob_predicate = vec![op::ret(RegId::ONE)].into_iter().collect::<Vec<u8>>();