Function populate_csv_partitions

datafusion/core/tests/sql/mod.rs:178–204

Generate CSV partitions within the supplied directory

(
    tmp_dir: &TempDir,
    partition_count: usize,
    file_extension: &str,
)

/// Generate CSV partitions within the supplied directory
fn populate_csv_partitions(
    tmp_dir: &TempDir,
    partition_count: usize,
    file_extension: &str,
) -> Result<SchemaRef> {
    // define schema for data source (csv file)
    let schema = Arc::new(Schema::new(vec![
        Field::new("c1", DataType::UInt32, false),
        Field::new("c2", DataType::UInt64, false),
        Field::new("c3", DataType::Boolean, false),
    ]));

    // generate a partitioned file
    for partition in 0..partition_count {
        let filename = format!("partition-{partition}.{file_extension}");
        let file_path = tmp_dir.path().join(filename);
        let mut file = File::create(file_path)?;

        // generate some data
        for i in 0..=10 {
            let data = format!("{},{},{}\n", partition, i, i % 2 == 0);
            file.write_all(data.as_bytes())?;
        }
    }

    Ok(schema)
}

/// Specialized String representation
fn col_str(column: &ArrayRef, row_index: usize) -> String {