FIX-#7624: Add proper implementation for Series.to_json

Resovles #7624

Signed-off-by: Devin Petersohn <[email protected]>

Author: sfc-gh-dpetersohn

modin/core/execution/dispatching/factories/dispatcher.py

@@ -400,6 +400,11 @@ def to_csv(cls, *args, **kwargs):
     def to_json(cls, *args, **kwargs):
         return cls.get_factory()._to_json(*args, **kwargs)
 
+    @classmethod
+    @_inherit_docstrings(factories.BaseFactory._to_json)
+    def to_json_series(cls, *args, **kwargs):
+        return cls.get_factory()._to_json_series(*args, **kwargs)
+
     @classmethod
     @_inherit_docstrings(factories.BaseFactory._to_xml)
     def to_xml(cls, *args, **kwargs):

modin/core/execution/dispatching/factories/factories.py

@@ -473,6 +473,20 @@ def _to_json(cls, *args, **kwargs):
         """
         return cls.io_cls.to_json(*args, **kwargs)
 
+    @classmethod
+    def _to_json_series(cls, *args, **kwargs):
+        """
+        Write query compiler content of a Series to a JSON file.
+
+        Parameters
+        ----------
+        *args : args
+            Arguments to pass to the writer method.
+        **kwargs : kwargs
+            Arguments to pass to the writer method.
+        """
+        return cls.io_cls.to_json_series(*args, **kwargs)
+
     @classmethod
     def _to_xml(cls, *args, **kwargs):
         """

modin/core/io/io.py

@@ -757,6 +757,20 @@ def to_json(cls, obj, path, **kwargs):  # noqa: PR01
 
         return obj.to_json(path, **kwargs)
 
+    @classmethod
+    @_inherit_docstrings(pandas.Series.to_json, apilink="pandas.Series.to_json")
+    def to_json_series(cls, obj, path, **kwargs):
+        """
+        Convert the object to a JSON string.
+
+        For parameters description please refer to pandas API.
+        """
+        cls._maybe_warn_on_default(message="`to_json`")
+        if isinstance(obj, BaseQueryCompiler):
+            obj = obj.to_pandas().squeeze(axis=1)
+
+        return obj.to_json(path, **kwargs)
+
     @classmethod
     @_inherit_docstrings(pandas.DataFrame.to_xml, apilink="pandas.DataFrame.to_xml")
     def to_xml(cls, obj, path_or_buffer, **kwargs):  # noqa: PR01

modin/pandas/series.py

@@ -22,7 +22,7 @@
 import numpy as np
 import pandas
 from pandas._libs import lib
-from pandas._typing import ArrayLike, Axis, DtypeObj, IndexKeyFunc, Scalar, Sequence
+from pandas._typing import ArrayLike, Axis, DtypeObj, IndexKeyFunc, Scalar, Sequence, StorageOptions
 from pandas.api.types import is_integer
 from pandas.core.arrays import ExtensionArray
 from pandas.core.common import apply_if_callable, is_bool_indexer
@@ -2189,6 +2189,44 @@ def to_frame(
 
         return DataFrame(self_cp)
 
+    def to_json(
+        self,
+        path_or_buf=None,
+        orient=None,
+        date_format=None,
+        double_precision=10,
+        force_ascii=True,
+        date_unit="ms",
+        default_handler=None,
+        lines=False,
+        compression="infer",
+        index=None,
+        indent=None,
+        storage_options: StorageOptions = None,
+        mode="w",
+    ) -> str | None:
+        from modin.core.execution.dispatching.factories.dispatcher import (
+            FactoryDispatcher,
+        )
+
+        return FactoryDispatcher.to_json_series(
+            self._query_compiler,
+            path_or_buf,
+            orient=orient,
+            date_format=date_format,
+            double_precision=double_precision,
+            force_ascii=force_ascii,
+            date_unit=date_unit,
+            default_handler=default_handler,
+            lines=lines,
+            compression=compression,
+            index=index,
+            indent=indent,
+            storage_options=storage_options,
+            mode=mode,
+        )
+
+
     def to_list(self) -> list:  # noqa: RT01, D200
         """
         Return a list of the values.

modin/tests/pandas/test_series.py

@@ -263,6 +263,15 @@ def test_to_list(data):
     assert np.array_equal(pd_res, md_res, equal_nan=True)
 
 
+@pytest.mark.parametrize("data", test_data_values, ids=test_data_keys)
+def test_to_json(data):
+    modin_series, pandas_series = create_test_series(data)
+    pd_res = pandas_series.to_json()
+    md_res = modin_series.to_json()
+    assert type(pd_res) is type(md_res)
+    assert pd_res == md_res
+
+
 def test_accessing_index_element_as_property():
     s = pd.Series([10, 20, 30], index=["a", "b", "c"])
     assert s.b == 20