diff --git a/src/s3/error.rs b/src/s3/error.rs
index 7d43120..c5a238b 100644
--- a/src/s3/error.rs
+++ b/src/s3/error.rs
@@ -46,6 +46,7 @@ pub enum ErrorCode {
     NotSupported,
     BucketNotEmpty,
     BucketAlreadyOwnedByYou,
+    InvalidWriteOffset,
 
     OtherError(String),
 }
@@ -76,6 +77,7 @@ impl ErrorCode {
             "notsupported" => ErrorCode::NotSupported,
             "bucketnotempty" => ErrorCode::BucketNotEmpty,
             "bucketalreadyownedbyyou" => ErrorCode::BucketAlreadyOwnedByYou,
+            "invalidwriteoffset" => ErrorCode::InvalidWriteOffset,
 
             v => ErrorCode::OtherError(v.to_owned()),
         }
diff --git a/src/s3/response/get_bucket_lifecycle.rs b/src/s3/response/get_bucket_lifecycle.rs
index 7cca980..e1e858a 100644
--- a/src/s3/response/get_bucket_lifecycle.rs
+++ b/src/s3/response/get_bucket_lifecycle.rs
@@ -65,8 +65,8 @@ impl FromS3Response for GetBucketLifecycleResponse {
         let headers: HeaderMap = mem::take(resp.headers_mut());
         let config: LifecycleConfig = {
             let body = resp.bytes().await?;
-            let mut root = Element::parse(body.reader())?;
-            LifecycleConfig::from_xml(&mut root)?
+            let root = Element::parse(body.reader())?;
+            LifecycleConfig::from_xml(&root)?
         };
         let updated_at: Option<DateTime<Utc>> = headers
             .get("x-minio-lifecycleconfig-updatedat")
diff --git a/tests/test_append_object.rs b/tests/test_append_object.rs
index 34de11f..014e718 100644
--- a/tests/test_append_object.rs
+++ b/tests/test_append_object.rs
@@ -14,6 +14,7 @@
 // limitations under the License.
 
 use minio::s3::builders::ObjectContent;
+use minio::s3::error::{Error, ErrorCode};
 use minio::s3::response::{
     AppendObjectResponse, GetObjectResponse, PutObjectContentResponse, PutObjectResponse,
     StatObjectResponse,
@@ -25,8 +26,51 @@ use minio_common::test_context::TestContext;
 use minio_common::utils::rand_object_name;
 use tokio::sync::mpsc;
 
+/// create an object with the given content and check that it is created correctly
+async fn create_object_helper(
+    content: &str,
+    bucket_name: &str,
+    object_name: &str,
+    ctx: &TestContext,
+) {
+    let data: SegmentedBytes = SegmentedBytes::from(content.to_string());
+    let size = content.len() as u64;
+    // create an object (with put) that contains "aaaa"
+    let resp: PutObjectResponse = ctx
+        .client
+        .put_object(bucket_name, object_name, data)
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+
+    let resp: GetObjectResponse = ctx
+        .client
+        .get_object(bucket_name, object_name)
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+    assert_eq!(resp.object_size, size);
+
+    // double check that the content we just have put is "aaaa"
+    let content1: String = String::from_utf8(
+        resp.content
+            .to_segmented_bytes()
+            .await
+            .unwrap()
+            .to_bytes()
+            .to_vec(),
+    )
+    .unwrap();
+    assert_eq!(content, content1);
+}
+
+/// Append to the end of an existing object (happy flow)
 #[tokio::test(flavor = "multi_thread", worker_threads = 10)]
-async fn append_object() {
+async fn append_object_0() {
     let ctx = TestContext::new_from_env();
     if !ctx.client.is_minio_express() {
         println!("Skipping test because it is NOT running in MinIO Express mode");
@@ -38,44 +82,16 @@ async fn append_object() {
 
     let content1 = "aaaa";
     let content2 = "bbbb";
-
     let size = content1.len() as u64;
-    let data1: SegmentedBytes = SegmentedBytes::from(content1.to_string());
+
+    create_object_helper(content1, &bucket_name, &object_name, &ctx).await;
+
+    // now append "bbbb" to the end of the object
     let data2: SegmentedBytes = SegmentedBytes::from(content2.to_string());
-
-    let resp: PutObjectResponse = ctx
-        .client
-        .put_object(&bucket_name, &object_name, data1)
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.bucket, bucket_name);
-    assert_eq!(resp.object, object_name);
-
-    let resp: GetObjectResponse = ctx
-        .client
-        .get_object(&bucket_name, &object_name)
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.bucket, bucket_name);
-    assert_eq!(resp.object, object_name);
-    assert_eq!(resp.object_size, size);
-
-    let content: String = String::from_utf8(
-        resp.content
-            .to_segmented_bytes()
-            .await
-            .unwrap()
-            .to_bytes()
-            .to_vec(),
-    )
-    .unwrap();
-    assert_eq!(content, content1);
-
+    let offset_bytes = size;
     let resp: AppendObjectResponse = ctx
         .client
-        .append_object(&bucket_name, &object_name, data2, size)
+        .append_object(&bucket_name, &object_name, data2, offset_bytes)
         .send()
         .await
         .unwrap();
@@ -90,6 +106,7 @@ async fn append_object() {
         .await
         .unwrap();
 
+    // retrieve the content of the object and check that it is "aaaabbbb"
     let content: String = String::from_utf8(
         resp.content
             .to_segmented_bytes()
@@ -106,6 +123,214 @@ async fn append_object() {
     assert_eq!(resp.object_size, size * 2);
 }
 
+/// Append to the beginning of an existing object (happy flow)
+#[tokio::test(flavor = "multi_thread", worker_threads = 10)]
+async fn append_object_1() {
+    let ctx = TestContext::new_from_env();
+    if !ctx.client.is_minio_express() {
+        println!("Skipping test because it is NOT running in MinIO Express mode");
+        return;
+    }
+
+    let (bucket_name, _cleanup) = ctx.create_bucket_helper().await;
+    let object_name = rand_object_name();
+
+    let content1 = "aaaa";
+    let content2 = "bbbb";
+    let size = content1.len() as u64;
+
+    create_object_helper(content1, &bucket_name, &object_name, &ctx).await;
+
+    // now append "bbbb" to the beginning of the object
+    let data2: SegmentedBytes = SegmentedBytes::from(content2.to_string());
+    let offset_bytes = 0; // byte 0, thus the beginning of the file
+    let resp: AppendObjectResponse = ctx
+        .client
+        .append_object(&bucket_name, &object_name, data2, offset_bytes)
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+    assert_eq!(resp.object_size, size);
+
+    let resp: GetObjectResponse = ctx
+        .client
+        .get_object(&bucket_name, &object_name)
+        .send()
+        .await
+        .unwrap();
+
+    // retrieve the content of the object and check that it is "bbbb"
+    let content: String = String::from_utf8(
+        resp.content
+            .to_segmented_bytes()
+            .await
+            .unwrap()
+            .to_bytes()
+            .to_vec(),
+    )
+    .unwrap();
+    assert_eq!(content, content2);
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+    assert_eq!(resp.object_size, size);
+}
+
+/// Append to the middle of an existing object (error InvalidWriteOffset)
+#[tokio::test(flavor = "multi_thread", worker_threads = 10)]
+async fn append_object_2() {
+    let ctx = TestContext::new_from_env();
+    if !ctx.client.is_minio_express() {
+        println!("Skipping test because it is NOT running in MinIO Express mode");
+        return;
+    }
+
+    let (bucket_name, _cleanup) = ctx.create_bucket_helper().await;
+    let object_name = rand_object_name();
+
+    let content1 = "aaaa";
+    let content2 = "bbbb";
+    let size = content1.len() as u64;
+
+    create_object_helper(content1, &bucket_name, &object_name, &ctx).await;
+
+    // now try to append "bbbb" to the object at an invalid offset
+    let offset_bytes = size - 1;
+    let data2: SegmentedBytes = SegmentedBytes::from(content2.to_string());
+    let resp: Result<AppendObjectResponse, Error> = ctx
+        .client
+        .append_object(&bucket_name, &object_name, data2, offset_bytes)
+        .send()
+        .await;
+
+    match resp {
+        Ok(v) => panic!("append object should have failed; got value: {:?}", v),
+        Err(Error::S3Error(e)) => {
+            assert_eq!(e.code, ErrorCode::InvalidWriteOffset);
+        }
+        Err(e) => panic!("append object should have failed; got error: {:?}", e),
+    }
+}
+
+/// Append beyond the size of an existing object (error InvalidWriteOffset)
+#[tokio::test(flavor = "multi_thread", worker_threads = 10)]
+async fn append_object_3() {
+    let ctx = TestContext::new_from_env();
+    if !ctx.client.is_minio_express() {
+        println!("Skipping test because it is NOT running in MinIO Express mode");
+        return;
+    }
+
+    let (bucket_name, _cleanup) = ctx.create_bucket_helper().await;
+    let object_name = rand_object_name();
+
+    let content1 = "aaaa";
+    let content2 = "bbbb";
+    let size = content1.len() as u64;
+
+    create_object_helper(content1, &bucket_name, &object_name, &ctx).await;
+
+    // now try to append "bbbb" to the object at an invalid offset
+    let data2: SegmentedBytes = SegmentedBytes::from(content2.to_string());
+    let offset_bytes = size + 1;
+    let resp: Result<AppendObjectResponse, Error> = ctx
+        .client
+        .append_object(&bucket_name, &object_name, data2, offset_bytes)
+        .send()
+        .await;
+
+    match resp {
+        Ok(v) => panic!("append object should have failed; got value: {:?}", v),
+        Err(Error::S3Error(e)) => {
+            assert_eq!(e.code, ErrorCode::InvalidWriteOffset);
+        }
+        Err(e) => panic!("append object should have failed; got error: {:?}", e),
+    }
+}
+
+/// Append to the beginning/end of a non-existing object (happy flow)
+#[tokio::test(flavor = "multi_thread", worker_threads = 10)]
+async fn append_object_4() {
+    let ctx = TestContext::new_from_env();
+    if !ctx.client.is_minio_express() {
+        println!("Skipping test because it is NOT running in MinIO Express mode");
+        return;
+    }
+
+    let (bucket_name, _cleanup) = ctx.create_bucket_helper().await;
+    let object_name = rand_object_name();
+
+    let content1 = "aaaa";
+    let size = content1.len() as u64;
+    let data1: SegmentedBytes = SegmentedBytes::from(content1.to_string());
+
+    // now append "bbbb" to the beginning of the object
+    let offset_bytes = 0; // byte 0, thus the beginning of the file
+    let resp: AppendObjectResponse = ctx
+        .client
+        .append_object(&bucket_name, &object_name, data1, offset_bytes)
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+    assert_eq!(resp.object_size, size);
+
+    let resp: GetObjectResponse = ctx
+        .client
+        .get_object(&bucket_name, &object_name)
+        .send()
+        .await
+        .unwrap();
+
+    // retrieve the content of the object and check that it is "aaaa"
+    let content: String = String::from_utf8(
+        resp.content
+            .to_segmented_bytes()
+            .await
+            .unwrap()
+            .to_bytes()
+            .to_vec(),
+    )
+    .unwrap();
+    assert_eq!(content, content1);
+    assert_eq!(resp.bucket, bucket_name);
+    assert_eq!(resp.object, object_name);
+    assert_eq!(resp.object_size, size);
+}
+
+/// Append beyond the size of a non-existing object (error NoSuchKey)
+#[tokio::test(flavor = "multi_thread", worker_threads = 10)]
+async fn append_object_5() {
+    let ctx = TestContext::new_from_env();
+    if !ctx.client.is_minio_express() {
+        println!("Skipping test because it is NOT running in MinIO Express mode");
+        return;
+    }
+
+    let (bucket_name, _cleanup) = ctx.create_bucket_helper().await;
+    let object_name = rand_object_name();
+
+    let content1 = "aaaa";
+    let data1: SegmentedBytes = SegmentedBytes::from(content1.to_string());
+
+    let offset_bytes = 1; // byte 1, thus beyond the current length of the (non-existing) file
+    let resp: Result<AppendObjectResponse, Error> = ctx
+        .client
+        .append_object(&bucket_name, &object_name, data1, offset_bytes)
+        .send()
+        .await;
+
+    match resp {
+        Ok(v) => panic!("append object should have failed; got value: {:?}", v),
+        Err(Error::S3Error(e)) => {
+            assert_eq!(e.code, ErrorCode::NoSuchKey);
+        }
+        Err(e) => panic!("append object should have failed; got error: {:?}", e),
+    }
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 10)]
 async fn append_object_content_0() {
     let ctx = TestContext::new_from_env();
@@ -119,39 +344,9 @@ async fn append_object_content_0() {
 
     let content1 = "aaaaa";
     let content2 = "bbbbb";
-
     let size = content1.len() as u64;
-    let data1: SegmentedBytes = SegmentedBytes::from(content1.to_string());
-    //let data2: SegmentedBytes = SegmentedBytes::from(content2.to_string());
 
-    let resp: PutObjectResponse = ctx
-        .client
-        .put_object(&bucket_name, &object_name, data1)
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.bucket, bucket_name);
-    assert_eq!(resp.object, object_name);
-
-    let resp: GetObjectResponse = ctx
-        .client
-        .get_object(&bucket_name, &object_name)
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(resp.bucket, bucket_name);
-    assert_eq!(resp.object, object_name);
-
-    let content: String = String::from_utf8(
-        resp.content
-            .to_segmented_bytes()
-            .await
-            .unwrap()
-            .to_bytes()
-            .to_vec(),
-    )
-    .unwrap();
-    assert_eq!(content, content1);
+    create_object_helper(content1, &bucket_name, &object_name, &ctx).await;
 
     let resp: AppendObjectResponse = ctx
         .client