Add tests for optimistic concurrency (#1962)

I think it would be great to also have integration tests that make it
easy to replicate certain scenarios.

Added some simple ones, but we can extend by having two tables that
modify a different partition etc.

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---------

Co-authored-by: smaheshwar-pltr <[email protected]>

Author: Fokko

tests/integration/test_writes/test_optimistic_concurrency.py

@@ -0,0 +1,93 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+import pyarrow as pa
+import pytest
+from pyspark.sql import SparkSession
+
+from pyiceberg.catalog import Catalog
+from pyiceberg.exceptions import CommitFailedException
+from utils import _create_table
+
+
+@pytest.mark.integration
+@pytest.mark.parametrize("format_version", [1, 2])
+def test_conflict_delete_delete(
+    spark: SparkSession, session_catalog: Catalog, arrow_table_with_null: pa.Table, format_version: int
+) -> None:
+    """This test should start passing once optimistic concurrency control has been implemented."""
+    identifier = "default.test_conflict"
+    tbl1 = _create_table(session_catalog, identifier, {"format-version": format_version}, [arrow_table_with_null])
+    tbl2 = session_catalog.load_table(identifier)
+
+    tbl1.delete("string == 'z'")
+
+    with pytest.raises(CommitFailedException, match="(branch main has changed: expected id ).*"):
+        # tbl2 isn't aware of the commit by tbl1
+        tbl2.delete("string == 'z'")
+
+
+@pytest.mark.integration
+@pytest.mark.parametrize("format_version", [1, 2])
+def test_conflict_delete_append(
+    spark: SparkSession, session_catalog: Catalog, arrow_table_with_null: pa.Table, format_version: int
+) -> None:
+    """This test should start passing once optimistic concurrency control has been implemented."""
+    identifier = "default.test_conflict"
+    tbl1 = _create_table(session_catalog, identifier, {"format-version": format_version}, [arrow_table_with_null])
+    tbl2 = session_catalog.load_table(identifier)
+
+    # This is allowed
+    tbl1.delete("string == 'z'")
+
+    with pytest.raises(CommitFailedException, match="(branch main has changed: expected id ).*"):
+        # tbl2 isn't aware of the commit by tbl1
+        tbl2.append(arrow_table_with_null)
+
+
+@pytest.mark.integration
+@pytest.mark.parametrize("format_version", [1, 2])
+def test_conflict_append_delete(
+    spark: SparkSession, session_catalog: Catalog, arrow_table_with_null: pa.Table, format_version: int
+) -> None:
+    """This test should start passing once optimistic concurrency control has been implemented."""
+    identifier = "default.test_conflict"
+    tbl1 = _create_table(session_catalog, identifier, {"format-version": format_version}, [arrow_table_with_null])
+    tbl2 = session_catalog.load_table(identifier)
+
+    tbl1.append(arrow_table_with_null)
+
+    with pytest.raises(CommitFailedException, match="(branch main has changed: expected id ).*"):
+        # tbl2 isn't aware of the commit by tbl1
+        tbl2.delete("string == 'z'")
+
+
+@pytest.mark.integration
+@pytest.mark.parametrize("format_version", [1, 2])
+def test_conflict_append_append(
+    spark: SparkSession, session_catalog: Catalog, arrow_table_with_null: pa.Table, format_version: int
+) -> None:
+    """This test should start passing once optimistic concurrency control has been implemented."""
+    identifier = "default.test_conflict"
+    tbl1 = _create_table(session_catalog, identifier, {"format-version": format_version}, [arrow_table_with_null])
+    tbl2 = session_catalog.load_table(identifier)
+
+    tbl1.append(arrow_table_with_null)
+
+    with pytest.raises(CommitFailedException, match="(branch main has changed: expected id ).*"):
+        # tbl2 isn't aware of the commit by tbl1
+        tbl2.append(arrow_table_with_null)