robin-sparkless 4.3.0

"""
Regression test for issue #1388: sql.describe_extended parity.

PySpark scenario (from the issue):

    def scenario_sql_describe_extended(session):
        df = session.createDataFrame([(1,)], ["x"])
        df.createOrReplaceTempView("t")
        return session.sql("DESCRIBE EXTENDED t")

This test exercises the same scenario against sparkless, ensuring that:

- ``session.sql(\"DESCRIBE EXTENDED t\")`` does not raise.
- The resulting schema's ``simpleString()`` matches the current struct form.
- The data includes at least the column ``x`` with a long/integer-like type.
- ``explain()`` returns a non-empty plan string (no blank UI).
"""

from sparkless.sql import SparkSession


def test_issue_1388_sql_describe_extended_schema_data_and_explain() -> None:
    """sql.describe_extended: schema, basic data, and explain behavior (issue #1388)."""
    spark = SparkSession.builder.appName("issue_1388").getOrCreate()
    try:
        df = spark.createDataFrame([(1,)], ["x"])
        df.createOrReplaceTempView("t")

        desc = spark.sql("DESCRIBE EXTENDED t")

        # Schema simpleString should match the current struct representation.
        schema_str = desc.schema.simpleString()
        assert schema_str == "struct<col_name:string,data_type:string>"

        # Data: ensure we at least describe column x with a long/integer-like type.
        rows = desc.collect()
        row_by_name = {row["col_name"]: row["data_type"] for row in rows}
        assert "x" in row_by_name
        assert row_by_name["x"] in {"long", "bigint", "int"}

        # explain() should produce a non-empty plan string.
        plan = desc.explain()
        assert isinstance(plan, str)
        assert plan.strip() != ""
    finally:
        spark.stop()