fix: Persist base64 string instead of bytes to ensure items are JSONa…

…ble (#1242)

This PR intends to persist b64 string inplace of bytes.
The latest isn't JSONable, so items can't be easily persisted without a
pickle backend.

skore/src/skore/persistence/item/altair_chart_item.py

@@ -7,8 +7,9 @@
 
 from typing import TYPE_CHECKING, Optional
 
-from .item import Item, ItemTypeError
-from .media_item import lazy_is_instance
+from skore.persistence.item.item import Item, ItemTypeError
+from skore.persistence.item.media_item import lazy_is_instance
+from skore.utils import bytes_to_b64_str
 
 if TYPE_CHECKING:
     from altair.vegalite.v5.schema.core import TopLevelSpec as AltairChart
@@ -71,10 +72,8 @@ def chart(self) -> AltairChart:
 
     def as_serializable_dict(self):
         """Convert item to a JSON-serializable dict to used by frontend."""
-        import base64
-
         chart_bytes = self.chart_str.encode("utf-8")
-        chart_b64_str = base64.b64encode(chart_bytes).decode()
+        chart_b64_str = bytes_to_b64_str(chart_bytes)
 
         return super().as_serializable_dict() | {
             "media_type": "application/vnd.vega.v5+json;base64",

skore/src/skore/persistence/item/cross_validation_reporter_item.py

@@ -20,9 +20,9 @@
 import plotly.graph_objects
 import plotly.io
 
+from skore.persistence.item.item import Item, ItemTypeError
 from skore.sklearn.cross_validation import CrossValidationReporter
-
-from .item import Item, ItemTypeError
+from skore.utils import b64_str_to_bytes, bytes_to_b64_str
 
 if TYPE_CHECKING:
     import sklearn.base
@@ -147,7 +147,7 @@ class CrossValidationReporterItem(Item):
 
     def __init__(
         self,
-        reporter_bytes: bytes,
+        reporter_b64_str: str,
         created_at: Optional[str] = None,
         updated_at: Optional[str] = None,
         note: Optional[str] = None,
@@ -157,7 +157,7 @@ def __init__(
 
         Parameters
         ----------
-        reporter_bytes : bytes
+        reporter_b64_str : str
             The raw bytes of the reporter pickled representation.
         created_at : str, optional
             The creation timestamp in ISO format.
@@ -168,7 +168,7 @@ def __init__(
         """
         super().__init__(created_at, updated_at, note)
 
-        self.reporter_bytes = reporter_bytes
+        self.reporter_b64_str = reporter_b64_str
 
     @classmethod
     def factory(
@@ -195,12 +195,17 @@ def factory(
         with io.BytesIO() as stream:
             joblib.dump(reporter, stream)
 
-            return cls(stream.getvalue(), **kwargs)
+            reporter_bytes = stream.getvalue()
+            reporter_b64_str = bytes_to_b64_str(reporter_bytes)
+
+            return cls(reporter_b64_str, **kwargs)
 
     @property
     def reporter(self) -> CrossValidationReporter:
         """The CrossValidationReporter from the persistence."""
-        with io.BytesIO(self.reporter_bytes) as stream:
+        reporter_bytes = b64_str_to_bytes(self.reporter_b64_str)
+
+        with io.BytesIO(reporter_bytes) as stream:
             return joblib.load(stream)
 
     def as_serializable_dict(self):

skore/src/skore/persistence/item/matplotlib_figure_item.py

@@ -5,14 +5,14 @@
 
 from __future__ import annotations
 
-from base64 import b64encode
 from io import BytesIO
 from typing import TYPE_CHECKING, Optional
 
 import joblib
 
-from .item import Item, ItemTypeError
-from .media_item import lazy_is_instance
+from skore.persistence.item.item import Item, ItemTypeError
+from skore.persistence.item.media_item import lazy_is_instance
+from skore.utils import b64_str_to_bytes, bytes_to_b64_str
 
 if TYPE_CHECKING:
     from matplotlib.figure import Figure
@@ -23,7 +23,7 @@ class MatplotlibFigureItem(Item):
 
     def __init__(
         self,
-        figure_bytes: str,
+        figure_b64_str: str,
         created_at: Optional[str] = None,
         updated_at: Optional[str] = None,
         note: Optional[str] = None,
@@ -33,7 +33,7 @@ def __init__(
 
         Parameters
         ----------
-        figure_bytes : bytes
+        figure_b64_str : str
             The raw bytes of the Matplotlib figure pickled representation.
         created_at : str, optional
             The creation timestamp in ISO format.
@@ -44,7 +44,7 @@ def __init__(
         """
         super().__init__(created_at, updated_at, note)
 
-        self.figure_bytes = figure_bytes
+        self.figure_b64_str = figure_b64_str
 
     @classmethod
     def factory(cls, figure: Figure, /, **kwargs) -> MatplotlibFigureItem:
@@ -67,12 +67,17 @@ def factory(cls, figure: Figure, /, **kwargs) -> MatplotlibFigureItem:
         with BytesIO() as stream:
             joblib.dump(figure, stream)
 
-            return cls(stream.getvalue(), **kwargs)
+            figure_bytes = stream.getvalue()
+            figure_b64_str = bytes_to_b64_str(figure_bytes)
+
+            return cls(figure_b64_str, **kwargs)
 
     @property
     def figure(self) -> Figure:
         """The figure from the persistence."""
-        with BytesIO(self.figure_bytes) as stream:
+        figure_bytes = b64_str_to_bytes(self.figure_b64_str)
+
+        with BytesIO(figure_bytes) as stream:
             return joblib.load(stream)
 
     def as_serializable_dict(self) -> dict:
@@ -81,7 +86,7 @@ def as_serializable_dict(self) -> dict:
             self.figure.savefig(stream, format="svg", bbox_inches="tight")
 
             figure_bytes = stream.getvalue()
-            figure_b64_str = b64encode(figure_bytes).decode()
+            figure_b64_str = bytes_to_b64_str(figure_bytes)
 
             return super().as_serializable_dict() | {
                 "media_type": "image/svg+xml;base64",

skore/src/skore/persistence/item/pickle_item.py

@@ -12,7 +12,8 @@
 
 import joblib
 
-from .item import Item
+from skore.persistence.item.item import Item
+from skore.utils import b64_str_to_bytes, bytes_to_b64_str
 
 
 class PickleItem(Item):
@@ -25,7 +26,7 @@ class PickleItem(Item):
 
     def __init__(
         self,
-        pickle_bytes: bytes,
+        pickle_b64_str: str,
         created_at: Optional[str] = None,
         updated_at: Optional[str] = None,
         note: Optional[str] = None,
@@ -35,7 +36,7 @@ def __init__(
 
         Parameters
         ----------
-        pickle_bytes : bytes
+        pickle_b64_str : str
             The raw bytes of the object pickled representation.
         created_at : str, optional
             The creation timestamp in ISO format.
@@ -46,7 +47,7 @@ def __init__(
         """
         super().__init__(created_at, updated_at, note)
 
-        self.pickle_bytes = pickle_bytes
+        self.pickle_b64_str = pickle_b64_str
 
     @classmethod
     def factory(cls, object: Any, /, **kwargs) -> PickleItem:
@@ -66,12 +67,17 @@ def factory(cls, object: Any, /, **kwargs) -> PickleItem:
         with BytesIO() as stream:
             joblib.dump(object, stream)
 
-            return cls(stream.getvalue(), **kwargs)
+            pickle_bytes = stream.getvalue()
+            pickle_b64_str = bytes_to_b64_str(pickle_bytes)
+
+            return cls(pickle_b64_str, **kwargs)
 
     @property
     def object(self) -> Any:
         """The object from the persistence."""
-        with BytesIO(self.pickle_bytes) as stream:
+        pickle_bytes = b64_str_to_bytes(self.pickle_b64_str)
+
+        with BytesIO(pickle_bytes) as stream:
             return joblib.load(stream)
 
     def as_serializable_dict(self):

skore/src/skore/persistence/item/pillow_image_item.py

@@ -5,10 +5,12 @@
 
 from __future__ import annotations
 
+from io import BytesIO
 from typing import TYPE_CHECKING, Optional
 
-from .item import Item, ItemTypeError
-from .media_item import lazy_is_instance
+from skore.persistence.item.item import Item, ItemTypeError
+from skore.persistence.item.media_item import lazy_is_instance
+from skore.utils import b64_str_to_bytes, bytes_to_b64_str
 
 if TYPE_CHECKING:
     import PIL.Image
@@ -19,7 +21,7 @@ class PillowImageItem(Item):
 
     def __init__(
         self,
-        image_bytes: bytes,
+        image_b64_str: str,
         image_mode: str,
         image_size: tuple[int],
         created_at: Optional[str] = None,
@@ -31,7 +33,7 @@ def __init__(
 
         Parameters
         ----------
-        image_bytes : bytes
+        image_b64_str : str
             The raw bytes of the Pillow image.
         image_mode : str
             The image mode.
@@ -46,7 +48,7 @@ def __init__(
         """
         super().__init__(created_at, updated_at, note)
 
-        self.image_bytes = image_bytes
+        self.image_b64_str = image_b64_str
         self.image_mode = image_mode
         self.image_size = image_size
 
@@ -68,8 +70,11 @@ def factory(cls, image: PIL.Image.Image, /, **kwargs) -> PillowImageItem:
         if not lazy_is_instance(image, "PIL.Image.Image"):
             raise ItemTypeError(f"Type '{image.__class__}' is not supported.")
 
+        image_bytes = image.tobytes()
+        image_b64_str = bytes_to_b64_str(image_bytes)
+
         return cls(
-            image_bytes=image.tobytes(),
+            image_b64_str=image_b64_str,
             image_mode=image.mode,
             image_size=image.size,
             **kwargs,
@@ -80,22 +85,21 @@ def image(self) -> PIL.Image.Image:
         """The image from the persistence."""
         import PIL.Image
 
+        image_bytes = b64_str_to_bytes(self.image_b64_str)
+
         return PIL.Image.frombytes(
             mode=self.image_mode,
             size=self.image_size,
-            data=self.image_bytes,
+            data=image_bytes,
         )
 
     def as_serializable_dict(self):
         """Convert item to a JSON-serializable dict to used by frontend."""
-        import base64
-        import io
-
-        with io.BytesIO() as stream:
+        with BytesIO() as stream:
             self.image.save(stream, format="png")
 
             png_bytes = stream.getvalue()
-            png_b64_str = base64.b64encode(png_bytes).decode()
+            png_b64_str = bytes_to_b64_str(png_bytes)
 
         return super().as_serializable_dict() | {
             "media_type": "image/png;base64",

skore/src/skore/persistence/item/plotly_figure_item.py

@@ -7,8 +7,9 @@
 
 from typing import TYPE_CHECKING, Optional
 
-from .item import Item, ItemTypeError
-from .media_item import lazy_is_instance
+from skore.persistence.item.item import Item, ItemTypeError
+from skore.persistence.item.media_item import lazy_is_instance
+from skore.utils import bytes_to_b64_str
 
 if TYPE_CHECKING:
     import plotly.basedatatypes
@@ -29,7 +30,7 @@ def __init__(
 
         Parameters
         ----------
-        figure_str : bytes
+        figure_str : str
             The JSON str of the Plotly figure.
         created_at : str, optional
             The creation timestamp in ISO format.
@@ -78,10 +79,8 @@ def figure(self) -> plotly.basedatatypes.BaseFigure:
 
     def as_serializable_dict(self):
         """Convert item to a JSON-serializable dict to used by frontend."""
-        import base64
-
         figure_bytes = self.figure_str.encode("utf-8")
-        figure_b64_str = base64.b64encode(figure_bytes).decode()
+        figure_b64_str = bytes_to_b64_str(figure_bytes)
 
         return super().as_serializable_dict() | {
             "media_type": "application/vnd.plotly.v1+json;base64",