From f73575ba6387ca18cdf5aea9669c9af43c947fd6 Mon Sep 17 00:00:00 2001
From: PierreDubrulle <dubrulle.pierre@proton.me>
Date: Sun, 12 Nov 2023 23:03:28 +0100
Subject: [PATCH] done

---
 crates/deltalake-core/src/table/mod.rs | 46 +++++++++++++++-----------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/crates/deltalake-core/src/table/mod.rs b/crates/deltalake-core/src/table/mod.rs
index 2d4511064b..53a59cb3d1 100644
--- a/crates/deltalake-core/src/table/mod.rs
+++ b/crates/deltalake-core/src/table/mod.rs
@@ -47,14 +47,18 @@ pub struct CheckPoint {
     pub(crate) version: i64, // 20 digits decimals
     /// The number of actions that are stored in the checkpoint.
     pub(crate) size: i64,
+    #[serde(skip_serializing_if = "Option::is_none")]
     /// The number of fragments if the last checkpoint was written in multiple parts. This field is optional.
     pub(crate) parts: Option<u32>, // 10 digits decimals
+    #[serde(skip_serializing_if = "Option::is_none")]
     /// The number of bytes of the checkpoint. This field is optional.
     pub(crate) size_in_bytes: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     /// The number of AddFile actions in the checkpoint. This field is optional.
     pub(crate) num_of_add_files: Option<i64>,
 }
 
+#[derive(Default)]
 /// Builder for CheckPoint
 pub struct CheckPointBuilder {
     /// Delta table version
@@ -76,9 +80,9 @@ impl CheckPointBuilder {
         CheckPointBuilder {
             version,
             size,
-            parts: Some(0),
+            parts: None,
             size_in_bytes: None,
-            num_of_add_files: Some(0),
+            num_of_add_files: None,
         }
     }
 
@@ -115,22 +119,12 @@ impl CheckPointBuilder {
 impl CheckPoint {
     /// Creates a new checkpoint from the given parameters.
     pub fn new(version: i64, size: i64, parts: Option<u32>) -> Self {
-        if parts.is_some() {
-            Self {
-                version,
-                size,
-                parts,
-                size_in_bytes: None,
-                num_of_add_files: Some(0),
-            }
-        } else {
-            Self {
-                version,
-                size,
-                parts: Some(0),
-                size_in_bytes: None,
-                num_of_add_files: Some(0),
-            }
+        Self {
+            version,
+            size,
+            parts: parts.or_else(|| None),
+            size_in_bytes: None,
+            num_of_add_files: None,
         }
     }
 }
@@ -920,12 +914,24 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn checkpoint_checker() {
+    async fn checkpoint_without_added_files_and_no_parts() {
         let (dt, tmp_dir) = create_test_table().await;
         let check_point = CheckPointBuilder::new(0, 0).build();
         let checkpoint_data_paths = dt.get_checkpoint_data_paths(&check_point);
         assert_eq!(checkpoint_data_paths.len(), 1);
-        println!("{:?}", check_point);
+        assert_eq!(serde_json::to_string(&check_point).unwrap(), "{\"version\":0,\"size\":0}");        
+        drop(tmp_dir);
+    }
+
+    #[tokio::test]
+    async fn checkpoint_with_added_files() {
+
+        let num_of_file_added: i64 = 4;
+        let (dt, tmp_dir) = create_test_table().await;
+        let check_point = CheckPointBuilder::new(0, 0).with_num_of_add_files(num_of_file_added).build();
+        let checkpoint_data_paths = dt.get_checkpoint_data_paths(&check_point);
+        assert_eq!(checkpoint_data_paths.len(), 1);
+        assert_eq!(serde_json::to_string(&check_point).unwrap(), "{\"version\":0,\"size\":0,\"num_of_add_files\":4}");
         drop(tmp_dir);
     }