bindings/python/tests/test_read.py

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import pickle
import tempfile

from pypaimon_rust.datafusion import PaimonCatalog, SQLContext


def _make_table_with_data(warehouse):
    ctx = SQLContext()
    ctx.register_catalog("paimon", {"warehouse": warehouse})
    ctx.sql("CREATE SCHEMA paimon.rdb")
    ctx.sql("CREATE TABLE paimon.rdb.t (id INT, name STRING)")
    ctx.sql("INSERT INTO paimon.rdb.t VALUES (1, 'a'), (2, 'b'), (3, 'c')")
    catalog = PaimonCatalog({"warehouse": warehouse})
    return catalog.get_table("rdb.t")


def test_read_builder_chain_exists():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        builder = table.new_read_builder()
        scan = builder.with_projection(["id"]).with_limit(2).new_scan()
        # plan() returns a Plan; deeper assertions are in later tasks.
        plan = scan.plan()
        assert plan is not None


def test_new_read_builder_plan():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        plan = table.new_read_builder().new_scan().plan()
        assert len(plan.splits()) >= 1


def test_with_projection():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        plan = table.new_read_builder().with_projection(["id"]).new_scan().plan()
        assert plan is not None


def test_with_limit():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        # limit is a planning hint; assert only that planning succeeds.
        plan = table.new_read_builder().with_limit(1).new_scan().plan()
        assert plan is not None


def test_plan_len():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        plan = table.new_read_builder().new_scan().plan()
        assert len(plan) == len(plan.splits())


def test_plan_without_filter_succeeds():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        plan = table.new_read_builder().new_scan().plan()
        assert len(plan.splits()) >= 1


def test_split_pickle_roundtrip():
    with tempfile.TemporaryDirectory() as warehouse:
        table = _make_table_with_data(warehouse)
        splits = table.new_read_builder().new_scan().plan().splits()
        assert len(splits) >= 1
        split = splits[0]
        restored = pickle.loads(pickle.dumps(split))
        assert restored.row_count() == split.row_count()