[Bug]: `write_deltalake` doesn't raise `ValueError` if the schema of the data passed differs from the existing table's schema

[nicolo-barboni]

What happened?

As the title suggests, an error doesn't get raised when the schemas are not matching.
Am i missing something?

Expected behavior

I would expect a ValueError, as described in the docs.

Operating System

macOS

Binding

Python

Bindings Version

1.2.1

Steps to reproduce

import datetime

import deltalake
import polars as pl

schema1 = pl.Schema({'id': pl.Int64, 'name': pl.String, 'age': pl.Int64})
schema2 = pl.Schema({'id': pl.Int64, 'name': pl.String, 'age': pl.Date})
schema3 = pl.Schema({'id': pl.Int64, 'name': pl.String, 'age': pl.String})

df1 = pl.DataFrame({'id': [1, 2], 'name': ['Alice', 'Bob'], 'age': [25, 30]}, schema=schema1)
df2 = pl.DataFrame(
    {'id': [10, 11], 'name': ['Simon', 'Tom'], 'age': [datetime.date(2025, 1, 1), datetime.date(2025, 1, 2)]},
    schema=schema2,
)
df3 = pl.DataFrame(
    {'id': [10, 11], 'name': ['Kate', 'John'], 'age': ['25', '30']},
    schema=schema3,
)
delta_path = 'test_delta_table'

deltalake.write_deltalake(str(delta_path), df1, mode='append')
deltalake.write_deltalake(str(delta_path), df2, mode='append')
deltalake.write_deltalake(str(delta_path), df3, mode='append')

df_read = pl.read_delta(str(delta_path))
print(df_read)

### Relevant logs

```shell
shape: (6, 3)
┌─────┬───────┬───────┐
│ id  ┆ name  ┆ age   │
│ --- ┆ ---   ┆ ---   │
│ i64 ┆ str   ┆ i64   │
╞═════╪═══════╪═══════╡
│ 10  ┆ Kate  ┆ 25    │
│ 11  ┆ John  ┆ 30    │
│ 10  ┆ Simon ┆ 20089 │
│ 11  ┆ Tom   ┆ 20090 │
│ 1   ┆ Alice ┆ 25    │
│ 2   ┆ Bob   ┆ 30    │
└─────┴───────┴───────┘

[ion-elgreco]

If the data can be cast then it's still written to the table.

[nicolo-barboni]

Ok, thanks for the answer!