add a test for writing data to disk

Author: kevinjqliu

tests/catalog/test_sql.py

@@ -19,6 +19,7 @@
 from pathlib import Path
 from typing import Generator, List
 
+import pyarrow as pa
 import pytest
 from pytest import TempPathFactory
 from pytest_lazyfixture import lazy_fixture
@@ -35,7 +36,9 @@
     NoSuchTableError,
     TableAlreadyExistsError,
 )
+from pyiceberg.io.pyarrow import schema_to_pyarrow
 from pyiceberg.schema import Schema
+from pyiceberg.table.snapshots import Operation
 from pyiceberg.table.sorting import (
     NullOrder,
     SortDirection,
@@ -722,6 +725,46 @@ def test_commit_table(catalog: SqlCatalog, table_schema_nested: Schema, random_i
     assert new_schema.find_field("b").field_type == IntegerType()
 
 
+@pytest.mark.parametrize(
+    'catalog',
+    [
+        lazy_fixture('catalog_memory'),
+        lazy_fixture('catalog_sqlite'),
+        lazy_fixture('catalog_sqlite_without_rowcount'),
+    ],
+)
+def test_append_table(catalog: SqlCatalog, table_schema_simple: Schema, random_identifier: Identifier) -> None:
+    database_name, _table_name = random_identifier
+    catalog.create_namespace(database_name)
+    table = catalog.create_table(random_identifier, table_schema_simple)
+
+    df = pa.Table.from_pydict(
+        {
+            "foo": ["a"],
+            "bar": [1],
+            "baz": [True],
+        },
+        schema=schema_to_pyarrow(table_schema_simple),
+    )
+
+    table.append(df)
+
+    # new snapshot is written in APPEND mode
+    assert len(table.metadata.snapshots) == 1
+    assert table.metadata.snapshots[0].snapshot_id == table.metadata.current_snapshot_id
+    assert table.metadata.snapshots[0].parent_snapshot_id is None
+    assert table.metadata.snapshots[0].sequence_number == 1
+    assert table.metadata.snapshots[0].summary is not None
+    assert table.metadata.snapshots[0].summary.operation == Operation.APPEND
+    assert table.metadata.snapshots[0].summary['added-data-files'] == '1'
+    assert table.metadata.snapshots[0].summary['added-records'] == '1'
+    assert table.metadata.snapshots[0].summary['total-data-files'] == '1'
+    assert table.metadata.snapshots[0].summary['total-records'] == '1'
+
+    # read back the data
+    assert df == table.scan().to_arrow()
+
+
 @pytest.mark.parametrize(
     'catalog',
     [