// 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.

use crate::builder::ArrayBuilder;

use crate::types::{ByteArrayType, GenericBinaryType, GenericStringType};

use crate::{Array, ArrayRef, GenericByteArray, OffsetSizeTrait};

use arrow_buffer::{ArrowNativeType, Buffer, MutableBuffer, NullBufferBuilder, ScalarBuffer};

use arrow_data::ArrayDataBuilder;

use std::any::Any;

use std::sync::Arc;

/// Builder for [`GenericByteArray`]

///

/// For building strings, see docs on [`GenericStringBuilder`].

/// For building binary, see docs on [`GenericBinaryBuilder`].

pub struct GenericByteBuilder<T: ByteArrayType> {

    value_builder: Vec<u8>,

    offsets_builder: Vec<T::Offset>,

    null_buffer_builder: NullBufferBuilder,

}

impl<T: ByteArrayType> GenericByteBuilder<T> {

    /// Creates a new [`GenericByteBuilder`].

    pub fn new() -> Self {

        Self::with_capacity(1024, 1024)

    }

    /// Creates a new [`GenericByteBuilder`].

    ///

    /// - `item_capacity` is the number of items to pre-allocate.

    ///   The size of the preallocated buffer of offsets is the number of items plus one.

    /// - `data_capacity` is the total number of bytes of data to pre-allocate

    ///   (for all items, not per item).

    pub fn with_capacity(item_capacity: usize, data_capacity: usize) -> Self {

        let mut offsets_builder = Vec::with_capacity(item_capacity + 1);

        offsets_builder.push(T::Offset::from_usize(0).unwrap());

        Self {

            value_builder: Vec::with_capacity(data_capacity),

            offsets_builder,

            null_buffer_builder: NullBufferBuilder::new(item_capacity),

        }

    }

    /// Creates a new  [`GenericByteBuilder`] from buffers.

    ///

    /// # Safety

    ///

    /// This doesn't verify buffer contents as it assumes the buffers are from

    /// existing and valid [`GenericByteArray`].

    pub unsafe fn new_from_buffer(

        offsets_buffer: MutableBuffer,

        value_buffer: MutableBuffer,

        null_buffer: Option<MutableBuffer>,

    ) -> Self {

        let offsets_builder: Vec<T::Offset> =

            ScalarBuffer::<T::Offset>::from(offsets_buffer).into();

        let value_builder: Vec<u8> = ScalarBuffer::<u8>::from(value_buffer).into();

        let null_buffer_builder = null_buffer

            .map(|buffer| NullBufferBuilder::new_from_buffer(buffer, offsets_builder.len() - 1))

            .unwrap_or_else(|| NullBufferBuilder::new_with_len(offsets_builder.len() - 1));

        Self {

            offsets_builder,

            value_builder,

            null_buffer_builder,

        }

    }

    #[inline]

    fn next_offset(&self) -> T::Offset {

        T::Offset::from_usize(self.value_builder.len()).expect("byte array offset overflow")

    }

    /// Appends a value into the builder.

    ///

    /// See the [GenericStringBuilder] documentation for examples of

    /// incrementally building string values with multiple `write!` calls.

    ///

    /// # Panics

    ///

    /// Panics if the resulting length of [`Self::values_slice`] would exceed

    /// `T::Offset::MAX` bytes.

    ///

    /// For example, this can happen with [`StringArray`] or [`BinaryArray`]

    /// where the total length of all values exceeds 2GB

    ///

    /// [`StringArray`]: crate::StringArray

    /// [`BinaryArray`]: crate::BinaryArray

    #[inline]

    pub fn append_value(&mut self, value: impl AsRef<T::Native>) {

        self.value_builder

            .extend_from_slice(value.as_ref().as_ref());

        self.null_buffer_builder.append(true);

        self.offsets_builder.push(self.next_offset());

    }

    /// Append an `Option` value into the builder.

    ///

    /// - A `None` value will append a null value.

    /// - A `Some` value will append the value.

    ///

    /// See [`Self::append_value`] for more panic information.

    #[inline]

    pub fn append_option(&mut self, value: Option<impl AsRef<T::Native>>) {

        match value {

            None => self.append_null(),

            Some(v) => self.append_value(v),

        };

    }

    /// Append a null value into the builder.

    #[inline]

    pub fn append_null(&mut self) {

        self.null_buffer_builder.append(false);

        self.offsets_builder.push(self.next_offset());

    }

    /// Appends `n` `null`s into the builder.

    #[inline]

    pub fn append_nulls(&mut self, n: usize) {

        self.null_buffer_builder.append_n_nulls(n);

        let next_offset = self.next_offset();

        self.offsets_builder

            .extend(std::iter::repeat_n(next_offset, n));

    }

    /// Appends array values and null to this builder as is

    /// (this means that underlying null values are copied as is).

    #[inline]

    pub fn append_array(&mut self, array: &GenericByteArray<T>) {

        if array.len() == 0 {

            return;

        }

        let offsets = array.offsets();

        // If the offsets are contiguous, we can append them directly avoiding the need to align

        // for example, when the first appended array is not sliced (starts at offset 0)

        if self.next_offset() == offsets[0] {

            self.offsets_builder.extend_from_slice(&offsets[1..]);

        } else {

            // Shifting all the offsets

            let shift: T::Offset = self.next_offset() - offsets[0];

            // Creating intermediate offsets instead of pushing each offset is faster

            // (even if we make MutableBuffer to avoid updating length on each push

            //  and reserve the necessary capacity, it's still slower)

            let mut intermediate = Vec::with_capacity(offsets.len() - 1);

            for &offset in &
offsets[1..]22
 {

                intermediate.push(offset + shift)

            }

            self.offsets_builder.extend_from_slice(&intermediate);

        }

        // Append underlying values, starting from the first offset and ending at the last offset

        self.value_builder.extend_from_slice(

            &array.values().as_slice()[offsets[0].as_usize()..offsets[array.len()].as_usize()],

        );

        if let Some(
null_buffer3
) = array.nulls() {

            self.null_buffer_builder.append_buffer(null_buffer);

        } else {

            self.null_buffer_builder.append_n_non_nulls(array.len());

        }

    }

    /// Builds the [`GenericByteArray`] and reset this builder.

    pub fn finish(&mut self) -> GenericByteArray<T> {

        let array_type = T::DATA_TYPE;

        let array_builder = ArrayDataBuilder::new(array_type)

            .len(self.len())

            .add_buffer(std::mem::take(&mut self.offsets_builder).into())

            .add_buffer(std::mem::take(&mut self.value_builder).into())

            .nulls(self.null_buffer_builder.finish());

        self.offsets_builder.push(self.next_offset());

        let array_data = unsafe { array_builder.build_unchecked() };

        GenericByteArray::from(array_data)

    }

    /// Builds the [`GenericByteArray`] without resetting the builder.

    pub fn finish_cloned(&self) -> GenericByteArray<T> {

        let array_type = T::DATA_TYPE;

        let offset_buffer = Buffer::from_slice_ref(self.offsets_builder.as_slice());

        let value_buffer = Buffer::from_slice_ref(self.value_builder.as_slice());

        let array_builder = ArrayDataBuilder::new(array_type)

            .len(self.len())

            .add_buffer(offset_buffer)

            .add_buffer(value_buffer)

            .nulls(self.null_buffer_builder.finish_cloned());

        let array_data = unsafe { array_builder.build_unchecked() };

        GenericByteArray::from(array_data)

    }

    /// Returns the current values buffer as a slice

    pub fn values_slice(&self) -> &[u8] {

        self.value_builder.as_slice()

    }

    /// Returns the current offsets buffer as a slice

    pub fn offsets_slice(&self) -> &[T::Offset] {

        self.offsets_builder.as_slice()

    }

    /// Returns the current null buffer as a slice

    pub fn validity_slice(&self) -> Option<&[u8]> {

        self.null_buffer_builder.as_slice()

    }

    /// Returns the current null buffer as a mutable slice

    pub fn validity_slice_mut(&mut self) -> Option<&mut [u8]> {

        self.null_buffer_builder.as_slice_mut()

    }

}

impl<T: ByteArrayType> std::fmt::Debug for GenericByteBuilder<T> {

    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

        write!(f, "{}{}Builder", T::Offset::PREFIX, T::PREFIX)?;

        f.debug_struct("")

            .field("value_builder", &self.value_builder)

            .field("offsets_builder", &self.offsets_builder)

            .field("null_buffer_builder", &self.null_buffer_builder)

            .finish()

    }

}

impl<T: ByteArrayType> Default for GenericByteBuilder<T> {

    fn default() -> Self {

        Self::new()

    }

}

impl<T: ByteArrayType> ArrayBuilder for GenericByteBuilder<T> {

    /// Returns the number of binary slots in the builder

    fn len(&self) -> usize {

        self.null_buffer_builder.len()

    }

    /// Builds the array and reset this builder.

    fn finish(&mut self) -> ArrayRef {

        Arc::new(self.finish())

    }

    /// Builds the array without resetting the builder.

    fn finish_cloned(&self) -> ArrayRef {

        Arc::new(self.finish_cloned())

    }

    /// Returns the builder as a non-mutable `Any` reference.

    fn as_any(&self) -> &dyn Any {

        self

    }

    /// Returns the builder as a mutable `Any` reference.

    fn as_any_mut(&mut self) -> &mut dyn Any {

        self

    }

    /// Returns the boxed builder as a box of `Any`.

    fn into_box_any(self: Box<Self>) -> Box<dyn Any> {

        self

    }

}

impl<T: ByteArrayType, V: AsRef<T::Native>> Extend<Option<V>> for GenericByteBuilder<T> {

    #[inline]

    fn extend<I: IntoIterator<Item = Option<V>>>(&mut self, iter: I) {

        for 
v27
 in iter {

            self.append_option(v)

        }

    }

}

/// Array builder for [`GenericStringArray`][crate::GenericStringArray]

///

/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with

/// [`GenericByteBuilder::append_null`].

///

/// This builder also implements [`std::fmt::Write`] with any written data

/// included in the next appended value. This allows using [`std::fmt::Display`]

/// with standard Rust idioms like `write!` and `writeln!` to write data

/// directly to the builder without intermediate allocations.

///

/// # Example writing strings with `append_value`

/// ```

/// # use arrow_array::builder::GenericStringBuilder;

/// let mut builder = GenericStringBuilder::<i32>::new();

///

/// // Write one string value

/// builder.append_value("foobarbaz");

///

/// // Write a second string

/// builder.append_value("v2");

///

/// let array = builder.finish();

/// assert_eq!(array.value(0), "foobarbaz");

/// assert_eq!(array.value(1), "v2");

/// ```

///

/// # Example incrementally writing strings with `std::fmt::Write`

///

/// ```

/// # use std::fmt::Write;

/// # use arrow_array::builder::GenericStringBuilder;

/// let mut builder = GenericStringBuilder::<i32>::new();

///

/// // Write data in multiple `write!` calls

/// write!(builder, "foo").unwrap();

/// write!(builder, "bar").unwrap();

/// // The next call to append_value finishes the current string

/// // including all previously written strings.

/// builder.append_value("baz");

///

/// // Write second value with a single write call

/// write!(builder, "v2").unwrap();

/// // finish the value by calling append_value with an empty string

/// builder.append_value("");

///

/// let array = builder.finish();

/// assert_eq!(array.value(0), "foobarbaz");

/// assert_eq!(array.value(1), "v2");

/// ```

pub type GenericStringBuilder<O> = GenericByteBuilder<GenericStringType<O>>;

impl<O: OffsetSizeTrait> std::fmt::Write for GenericStringBuilder<O> {

    fn write_str(&mut self, s: &str) -> std::fmt::Result {

        self.value_builder.extend_from_slice(s.as_bytes());

        Ok(())

    }

}

///  Array builder for [`GenericBinaryArray`][crate::GenericBinaryArray]

///

/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with

/// [`GenericByteBuilder::append_null`].

///

/// # Example

/// ```

/// # use arrow_array::builder::GenericBinaryBuilder;

/// let mut builder = GenericBinaryBuilder::<i32>::new();

///

/// // Write data

/// builder.append_value("foo");

///

/// // Write second value

/// builder.append_value(&[0,1,2]);

///

/// let array = builder.finish();

/// // binary values

/// assert_eq!(array.value(0), b"foo");

/// assert_eq!(array.value(1), b"\x00\x01\x02");

/// ```

///

/// # Example incrementally writing bytes with `write_bytes`

///

/// ```

/// # use std::io::Write;

/// # use arrow_array::builder::GenericBinaryBuilder;

/// let mut builder = GenericBinaryBuilder::<i32>::new();

///

/// // Write data in multiple `write_bytes` calls

/// write!(builder, "foo").unwrap();

/// write!(builder, "bar").unwrap();

/// // The next call to append_value finishes the current string

/// // including all previously written strings.

/// builder.append_value("baz");

///

/// // Write second value with a single write call

/// write!(builder, "v2").unwrap();

/// // finish the value by calling append_value with an empty string

/// builder.append_value("");

///

/// let array = builder.finish();

/// assert_eq!(array.value(0), "foobarbaz".as_bytes());

/// assert_eq!(array.value(1), "v2".as_bytes());

/// ```

pub type GenericBinaryBuilder<O> = GenericByteBuilder<GenericBinaryType<O>>;

impl<O: OffsetSizeTrait> std::io::Write for GenericBinaryBuilder<O> {

    fn write(&mut self, bs: &[u8]) -> std::io::Result<usize> {

        self.value_builder.extend_from_slice(bs);

        Ok(bs.len())

    }

    fn flush(&mut self) -> std::io::Result<()> {

        Ok(())

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    use crate::array::Array;

    use crate::GenericStringArray;

    use arrow_buffer::NullBuffer;

    use std::fmt::Write as _;

    use std::io::Write as _;

    fn _test_generic_binary_builder<O: OffsetSizeTrait>() {

        let mut builder = GenericBinaryBuilder::<O>::new();

        builder.append_value(b"hello");

        builder.append_value(b"");

        builder.append_null();

        builder.append_value(b"rust");

        let array = builder.finish();

        assert_eq!(4, array.len());

        assert_eq!(1, array.null_count());

        assert_eq!(b"hello", array.value(0));

        assert_eq!([] as [u8; 0], array.value(1));

        assert!(array.is_null(2));

        assert_eq!(b"rust", array.value(3));

        assert_eq!(O::from_usize(5).unwrap(), array.value_offsets()[2]);

        assert_eq!(O::from_usize(4).unwrap(), array.value_length(3));

    }

    #[test]

    fn test_binary_builder() {

        _test_generic_binary_builder::<i32>()

    }

    #[test]

    fn test_large_binary_builder() {

        _test_generic_binary_builder::<i64>()

    }

    fn _test_generic_binary_builder_all_nulls<O: OffsetSizeTrait>() {

        let mut builder = GenericBinaryBuilder::<O>::new();

        builder.append_null();

        builder.append_null();

        builder.append_null();

        builder.append_nulls(2);

        assert_eq!(5, builder.len());

        assert!(!builder.is_empty());

        let array = builder.finish();

        assert_eq!(5, array.null_count());

        assert_eq!(5, array.len());

        assert!(array.is_null(0));

        assert!(array.is_null(1));

        assert!(array.is_null(2));

        assert!(array.is_null(3));

        assert!(array.is_null(4));

    }

    #[test]

    fn test_binary_builder_all_nulls() {

        _test_generic_binary_builder_all_nulls::<i32>()

    }

    #[test]

    fn test_large_binary_builder_all_nulls() {

        _test_generic_binary_builder_all_nulls::<i64>()

    }

    fn _test_generic_binary_builder_reset<O: OffsetSizeTrait>() {

        let mut builder = GenericBinaryBuilder::<O>::new();

        builder.append_value(b"hello");

        builder.append_value(b"");

        builder.append_null();

        builder.append_value(b"rust");

        builder.finish();

        assert!(builder.is_empty());

        builder.append_value(b"parquet");

        builder.append_null();

        builder.append_value(b"arrow");

        builder.append_value(b"");

        builder.append_nulls(2);

        builder.append_value(b"hi");

        let array = builder.finish();

        assert_eq!(7, array.len());

        assert_eq!(3, array.null_count());

        assert_eq!(b"parquet", array.value(0));

        assert!(array.is_null(1));

        assert!(array.is_null(4));

        assert!(array.is_null(5));

        assert_eq!(b"arrow", array.value(2));

        assert_eq!(b"", array.value(1));

        assert_eq!(b"hi", array.value(6));

        assert_eq!(O::zero(), array.value_offsets()[0]);

        assert_eq!(O::from_usize(7).unwrap(), array.value_offsets()[2]);

        assert_eq!(O::from_usize(14).unwrap(), array.value_offsets()[7]);

        assert_eq!(O::from_usize(5).unwrap(), array.value_length(2));

    }

    #[test]

    fn test_binary_builder_reset() {

        _test_generic_binary_builder_reset::<i32>()

    }

    #[test]

    fn test_large_binary_builder_reset() {

        _test_generic_binary_builder_reset::<i64>()

    }

    fn _test_generic_string_array_builder<O: OffsetSizeTrait>() {

        let mut builder = GenericStringBuilder::<O>::new();

        let owned = "arrow".to_owned();

        builder.append_value("hello");

        builder.append_value("");

        builder.append_value(&owned);

        builder.append_null();

        builder.append_option(Some("rust"));

        builder.append_option(None::<&str>);

        builder.append_option(None::<String>);

        builder.append_nulls(2);

        builder.append_value("parquet");

        assert_eq!(10, builder.len());

        assert_eq!(

            GenericStringArray::<O>::from(vec![

                Some("hello"),

                Some(""),

                Some("arrow"),

                None,

                Some("rust"),

                None,

                None,

                None,

                None,

                Some("parquet")

            ]),

            builder.finish()

        );

    }

    #[test]

    fn test_string_array_builder() {

        _test_generic_string_array_builder::<i32>()

    }

    #[test]

    fn test_large_string_array_builder() {

        _test_generic_string_array_builder::<i64>()

    }

    fn _test_generic_string_array_builder_finish<O: OffsetSizeTrait>() {

        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);

        builder.append_value("hello");

        builder.append_value("rust");

        builder.append_null();

        builder.finish();

        assert!(builder.is_empty());

        assert_eq!(&[O::zero()], builder.offsets_slice());

        builder.append_value("arrow");

        builder.append_value("parquet");

        let arr = builder.finish();

        // array should not have null buffer because there is not `null` value.

        assert!(arr.nulls().is_none());

        assert_eq!(GenericStringArray::<O>::from(vec!["arrow", "parquet"]), arr,)

    }

    #[test]

    fn test_string_array_builder_finish() {

        _test_generic_string_array_builder_finish::<i32>()

    }

    #[test]

    fn test_large_string_array_builder_finish() {

        _test_generic_string_array_builder_finish::<i64>()

    }

    fn _test_generic_string_array_builder_finish_cloned<O: OffsetSizeTrait>() {

        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);

        builder.append_value("hello");

        builder.append_value("rust");

        builder.append_null();

        let mut arr = builder.finish_cloned();

        assert!(!builder.is_empty());

        assert_eq!(3, arr.len());

        builder.append_value("arrow");

        builder.append_value("parquet");

        arr = builder.finish();

        assert!(arr.nulls().is_some());

        assert_eq!(&[O::zero()], builder.offsets_slice());

        assert_eq!(5, arr.len());

    }

    #[test]

    fn test_string_array_builder_finish_cloned() {

        _test_generic_string_array_builder_finish_cloned::<i32>()

    }

    #[test]

    fn test_large_string_array_builder_finish_cloned() {

        _test_generic_string_array_builder_finish_cloned::<i64>()

    }

    #[test]

    fn test_extend() {

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.extend(["a", "b", "c", "", "a", "b", "c"].into_iter().map(Some));

        builder.extend(["d", "cupcakes", "hello"].into_iter().map(Some));

        let array = builder.finish();

        assert_eq!(array.value_offsets(), &[0, 1, 2, 3, 3, 4, 5, 6, 7, 15, 20]);

        assert_eq!(array.value_data(), b"abcabcdcupcakeshello");

    }

    #[test]

    fn test_write_str() {

        let mut builder = GenericStringBuilder::<i32>::new();

        write!(builder, "foo").unwrap();

        builder.append_value("");

        writeln!(builder, "bar").unwrap();

        builder.append_value("");

        write!(builder, "fiz").unwrap();

        write!(builder, "buz").unwrap();

        builder.append_value("");

        let a = builder.finish();

        let r: Vec<_> = a.iter().flatten().collect();

        assert_eq!(r, &["foo", "bar\n", "fizbuz"])

    }

    #[test]

    fn test_write_bytes() {

        let mut builder = GenericBinaryBuilder::<i32>::new();

        write!(builder, "foo").unwrap();

        builder.append_value("");

        writeln!(builder, "bar").unwrap();

        builder.append_value("");

        write!(builder, "fiz").unwrap();

        write!(builder, "buz").unwrap();

        builder.append_value("");

        let a = builder.finish();

        let r: Vec<_> = a.iter().flatten().collect();

        assert_eq!(

            r,

            &["foo".as_bytes(), "bar\n".as_bytes(), "fizbuz".as_bytes()]

        )

    }

    #[test]

    fn test_append_array_without_nulls() {

        let input = vec![

            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",

            "thank", "you", "for", "asking",

        ];

        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());

        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());

        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&arr1);

        builder.append_array(&arr2);

        builder.append_array(&arr3);

        let actual = builder.finish();

        let expected = GenericStringArray::<i32>::from(input);

        assert_eq!(actual, expected);

    }

    #[test]

    fn test_append_array_with_nulls() {

        let input = vec![

            Some("hello"),

            None,

            Some("how"),

            None,

            None,

            None,

            None,

            Some("I"),

            Some("am"),

            Some("doing"),

            Some("well"),

        ];

        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());

        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());

        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&arr1);

        builder.append_array(&arr2);

        builder.append_array(&arr3);

        let actual = builder.finish();

        let expected = GenericStringArray::<i32>::from(input);

        assert_eq!(actual, expected);

    }

    #[test]

    fn test_append_empty_array() {

        let arr = GenericStringArray::<i32>::from(Vec::<&str>::new());

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&arr);

        let result = builder.finish();

        assert_eq!(result.len(), 0);

    }

    #[test]

    fn test_append_array_with_offset_not_starting_at_0() {

        let input = vec![

            Some("hello"),

            None,

            Some("how"),

            None,

            None,

            None,

            None,

            Some("I"),

            Some("am"),

            Some("doing"),

            Some("well"),

        ];

        let full_array = GenericStringArray::<i32>::from(input);

        let sliced = full_array.slice(1, 4);

        assert_ne!(sliced.offsets()[0].as_usize(), 0);

        assert_ne!(sliced.offsets().last(), full_array.offsets().last());

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&sliced);

        let actual = builder.finish();

        let expected = GenericStringArray::<i32>::from(vec![None, Some("how"), None, None]);

        assert_eq!(actual, expected);

    }

    #[test]

    fn test_append_underlying_null_values_added_as_is() {

        let input_1_array_with_nulls = {

            let input = vec![

                "hello", "world", "how", "are", "you", "doing", "today", "I", "am",

            ];

            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();

            GenericStringArray::<i32>::new(

                offsets,

                buffer,

                Some(NullBuffer::from(&[

                    true, false, true, false, false, true, true, true, false,

                ])),

            )

        };

        let input_2_array_with_nulls = {

            let input = vec!["doing", "well", "thank", "you", "for", "asking"];

            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();

            GenericStringArray::<i32>::new(

                offsets,

                buffer,

                Some(NullBuffer::from(&[false, false, true, false, true, true])),

            )

        };

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&input_1_array_with_nulls);

        builder.append_array(&input_2_array_with_nulls);

        let actual = builder.finish();

        let expected = GenericStringArray::<i32>::from(vec![

            Some("hello"),

            None, // world

            Some("how"),

            None, // are

            None, // you

            Some("doing"),

            Some("today"),

            Some("I"),

            None, // am

            None, // doing

            None, // well

            Some("thank"),

            None, // "you",

            Some("for"),

            Some("asking"),

        ]);

        assert_eq!(actual, expected);

        let expected_underlying_buffer = Buffer::from(

            [

                "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing",

                "well", "thank", "you", "for", "asking",

            ]

            .join("")

            .as_bytes(),

        );

        assert_eq!(actual.values(), &expected_underlying_buffer);

    }

    #[test]

    fn append_array_with_continues_indices() {

        let input = vec![

            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",

            "thank", "you", "for", "asking",

        ];

        let full_array = GenericStringArray::<i32>::from(input);

        let slice1 = full_array.slice(0, 3);

        let slice2 = full_array.slice(3, 4);

        let slice3 = full_array.slice(7, full_array.len() - 7);

        let mut builder = GenericStringBuilder::<i32>::new();

        builder.append_array(&slice1);

        builder.append_array(&slice2);

        builder.append_array(&slice3);

        let actual = builder.finish();

        assert_eq!(actual, full_array);

    }

}