From 8c24d3206fa2450fd95421efdb1882f93018a2e5 Mon Sep 17 00:00:00 2001
From: Marko Grujic <markoog@gmail.com>
Date: Wed, 29 Nov 2023 14:59:41 +0100
Subject: [PATCH] Add integration test for the CONVERT TO DELTA statement

---
 tests/statements/convert.rs | 76 +++++++++++++++++++++++++++++++++++++
 tests/statements/mod.rs     |  3 ++
 2 files changed, 79 insertions(+)
 create mode 100644 tests/statements/convert.rs

diff --git a/tests/statements/convert.rs b/tests/statements/convert.rs
new file mode 100644
index 00000000..7b70e009
--- /dev/null
+++ b/tests/statements/convert.rs
@@ -0,0 +1,76 @@
+use crate::statements::*;
+
+#[tokio::test]
+async fn test_convert_from_flat_parquet_table() -> Result<(), DataFusionError> {
+    let (context, maybe_test_dir) = make_context_with_pg(ObjectStoreType::Local).await;
+
+    // Prepare a flat Parquet table
+    let table_uuid = Uuid::new_v4();
+    let temp_dir = maybe_test_dir.expect("temporary data dir exists");
+    let table_path = temp_dir.path().join(table_uuid.to_string());
+    // Create the directory as otherwise the COPY will fail
+    create_dir(table_path.clone()).await?;
+
+    // COPY the existing table multiple times to test converting flat table with more than one
+    // parquet file
+    context
+        .plan_query(&format!(
+            "COPY (VALUES (1, 'one'), (2, 'two')) TO '{}/file_1.parquet'",
+            table_path.display()
+        ))
+        .await?;
+    context
+        .plan_query(&format!(
+            "COPY (VALUES (3, 'three'), (4, 'four')) TO '{}/file_2.parquet'",
+            table_path.display()
+        ))
+        .await?;
+    context
+        .plan_query(&format!(
+            "COPY (VALUES (5, 'five'), (6, 'six')) TO '{}/file_3.parquet'",
+            table_path.display()
+        ))
+        .await?;
+
+    // Now test the actual conversion
+    context
+        .plan_query(&format!("CONVERT '{table_uuid}' TO DELTA table_converted"))
+        .await?;
+
+    // Finally test the contents of the converted table
+    let plan = context
+        .plan_query("SELECT * FROM table_converted ORDER BY column1")
+        .await?;
+    let results = context.collect(plan).await.unwrap();
+
+    let expected = [
+        "+---------+---------+",
+        "| column1 | column2 |",
+        "+---------+---------+",
+        "| 1       | one     |",
+        "| 2       | two     |",
+        "| 3       | three   |",
+        "| 4       | four    |",
+        "| 5       | five    |",
+        "| 6       | six     |",
+        "+---------+---------+",
+    ];
+    assert_batches_eq!(expected, &results);
+
+    // Also check the final directory state
+    testutils::assert_uploaded_objects(
+        context
+            .internal_object_store
+            .get_log_store(table_uuid)
+            .object_store(),
+        vec![
+            Path::from("_delta_log/00000000000000000000.json"),
+            Path::from("file_1.parquet"),
+            Path::from("file_2.parquet"),
+            Path::from("file_3.parquet"),
+        ],
+    )
+    .await;
+
+    Ok(())
+}
diff --git a/tests/statements/mod.rs b/tests/statements/mod.rs
index f15d0a43..04ed17d3 100644
--- a/tests/statements/mod.rs
+++ b/tests/statements/mod.rs
@@ -17,7 +17,9 @@ use serde_json::json;
 use sqlx::{any::install_default_drivers, AnyPool, Executor};
 #[cfg(feature = "remote-tables")]
 use tempfile::{NamedTempFile, TempPath};
+use tokio::fs::create_dir;
 use tokio::time::sleep;
+use uuid::Uuid;
 
 use rstest::rstest;
 use tempfile::TempDir;
@@ -34,6 +36,7 @@ mod dml;
 mod query;
 // Hack because integration tests do not set cfg(test)
 // https://users.rust-lang.org/t/sharing-helper-function-between-unit-and-integration-tests/9941/2
+mod convert;
 #[allow(dead_code)]
 #[path = "../../src/testutils.rs"]
 mod testutils;