From c7ac7b324e12b420014ed8fa7c102b2f5dc22be4 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Tue, 6 Jun 2023 00:00:02 -0600
Subject: [PATCH 01/13] report better error for attrs that cannot be serialized

also misc changes to config options to make this eaiser
in particular ability to specify options as parents
---
 src/py/reactpy/reactpy/_option.py    | 46 ++++++++++++--------
 src/py/reactpy/reactpy/config.py     | 63 ++++++++++++++++++----------
 src/py/reactpy/reactpy/core/serve.py | 14 ++++++-
 src/py/reactpy/reactpy/core/vdom.py  |  5 ++-
 src/py/reactpy/tests/test__option.py | 25 +++++++++--
 src/py/reactpy/tests/test_utils.py   |  4 --
 6 files changed, 108 insertions(+), 49 deletions(-)

diff --git a/src/py/reactpy/reactpy/_option.py b/src/py/reactpy/reactpy/_option.py
index 1421f33a3..5475fbb8e 100644
--- a/src/py/reactpy/reactpy/_option.py
+++ b/src/py/reactpy/reactpy/_option.py
@@ -8,6 +8,13 @@
 
 _O = TypeVar("_O")
 logger = getLogger(__name__)
+UNDEFINED = cast(Any, object())
+
+
+def deprecate(option: Option[_O], message: str) -> Option[_O]:
+    option.__class__ = _DeprecatedOption
+    option._deprecation_message = message
+    return option
 
 
 class Option(Generic[_O]):
@@ -16,8 +23,9 @@ class Option(Generic[_O]):
     def __init__(
         self,
         name: str,
-        default: _O | Option[_O],
+        default: _O = UNDEFINED,
         mutable: bool = True,
+        parent: Option[_O] | None = None,
         validator: Callable[[Any], _O] = lambda x: cast(_O, x),
     ) -> None:
         self._name = name
@@ -28,12 +36,15 @@ def __init__(
         if name in os.environ:
             self._current = validator(os.environ[name])
 
-        self._default: _O
-        if isinstance(default, Option):
-            self._default = default.default
-            default.subscribe(lambda value: setattr(self, "_default", value))
-        else:
+        if parent is not None:
+            if not (parent.mutable and self.mutable):
+                raise TypeError("Parent and child options must be mutable")
+            self._default = parent.default
+            parent.subscribe(self.set_current)
+        elif default is not UNDEFINED:
             self._default = default
+        else:
+            raise TypeError("Must specify either a default or a parent option")
 
         logger.debug(f"{self._name}={self.current}")
 
@@ -81,11 +92,19 @@ def set_current(self, new: Any) -> None:
 
         Raises a ``TypeError`` if this option is not :attr:`Option.mutable`.
         """
+        old = self.current
+        if new is old:
+            return None
+
         if not self._mutable:
             msg = f"{self} cannot be modified after initial load"
             raise TypeError(msg)
-        old = self.current
-        new = self._current = self._validator(new)
+
+        try:
+            new = self._current = self._validator(new)
+        except ValueError as error:
+            raise ValueError(f"Invalid value for {self._name}: {new!r}") from error
+
         logger.debug(f"{self._name}={self._current}")
         if new != old:
             for sub_func in self._subscribers:
@@ -119,15 +138,8 @@ def __repr__(self) -> str:
         return f"Option({self._name}={self.current!r})"
 
 
-class DeprecatedOption(Option[_O]):  # nocov
-    def __init__(self, message: str, *args: Any, **kwargs: Any) -> None:
-        self._deprecation_message = message
-        super().__init__(*args, **kwargs)
-
+class _DeprecatedOption(Option[_O]):  # nocov
     @Option.current.getter  # type: ignore
     def current(self) -> _O:
-        warn(
-            self._deprecation_message,
-            DeprecationWarning,
-        )
+        warn(self._deprecation_message, DeprecationWarning)
         return super().current
diff --git a/src/py/reactpy/reactpy/config.py b/src/py/reactpy/reactpy/config.py
index 6dc29096c..a80031ef4 100644
--- a/src/py/reactpy/reactpy/config.py
+++ b/src/py/reactpy/reactpy/config.py
@@ -6,41 +6,58 @@
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
-from reactpy._option import Option as _Option
+from reactpy._option import Option
 
-REACTPY_DEBUG_MODE = _Option(
-    "REACTPY_DEBUG_MODE",
-    default=False,
-    validator=lambda x: bool(int(x)),
-)
-"""This immutable option turns on/off debug mode
+TRUE_VALUES = {"true", "1"}
+FALSE_VALUES = {"false", "0"}
 
-The string values ``1`` and ``0`` are mapped to ``True`` and ``False`` respectively.
 
-When debug is on, extra validation measures are applied that negatively impact
-performance but can be used to catch bugs during development. Additionally, the default
-log level for ReactPy is set to ``DEBUG``.
-"""
+def boolean(value: str | bool) -> bool:
+    if isinstance(value, bool):
+        return value
+    elif not isinstance(value, str):
+        raise TypeError(f"Expected str or bool, got {type(value).__name__}")
+
+    if value.lower() in TRUE_VALUES:
+        return True
+    elif value.lower() in FALSE_VALUES:
+        return False
+    else:
+        raise ValueError(
+            f"Invalid boolean value {value!r} - expected "
+            f"one of {list(TRUE_VALUES | FALSE_VALUES)}"
+        )
 
-REACTPY_CHECK_VDOM_SPEC = _Option(
-    "REACTPY_CHECK_VDOM_SPEC",
-    default=REACTPY_DEBUG_MODE,
-    validator=lambda x: bool(int(x)),
+
+REACTPY_DEBUG_MODE = Option(
+    "REACTPY_DEBUG_MODE", default=False, validator=boolean, mutable=True
 )
-"""This immutable option turns on/off checks which ensure VDOM is rendered to spec
+"""Get extra logs and validation checks at the cost of performance.
 
-The string values ``1`` and ``0`` are mapped to ``True`` and ``False`` respectively.
+This will enable the following:
 
-By default this check is off. When ``REACTPY_DEBUG_MODE=1`` this will be turned on but can
-be manually disablled by setting ``REACTPY_CHECK_VDOM_SPEC=0`` in addition.
+- :data:`REACTPY_CHECK_VDOM_SPEC`
+- :data:`REACTPY_CHECK_JSON_ATTRS`
+"""
+
+REACTPY_CHECK_VDOM_SPEC = Option("REACTPY_CHECK_VDOM_SPEC", parent=REACTPY_DEBUG_MODE)
+"""Checks which ensure VDOM is rendered to spec
 
 For more info on the VDOM spec, see here: :ref:`VDOM JSON Schema`
 """
 
-# Because these web modules will be linked dynamically at runtime this can be temporary
+REACTPY_CHECK_JSON_ATTRS = Option("REACTPY_CHECK_JSON_ATTRS", parent=REACTPY_DEBUG_MODE)
+"""Checks that all VDOM attributes are JSON serializable
+
+The VDOM spec is not able to enforce this on its own since attributes could anything.
+"""
+
+# Because these web modules will be linked dynamically at runtime this can be temporary.
+# Assigning to a variable here ensures that the directory is not deleted until the end
+# of the program.
 _DEFAULT_WEB_MODULES_DIR = TemporaryDirectory()
 
-REACTPY_WEB_MODULES_DIR = _Option(
+REACTPY_WEB_MODULES_DIR = Option(
     "REACTPY_WEB_MODULES_DIR",
     default=Path(_DEFAULT_WEB_MODULES_DIR.name),
     validator=Path,
@@ -52,7 +69,7 @@
 set of publicly available APIs for working with the client.
 """
 
-REACTPY_TESTING_DEFAULT_TIMEOUT = _Option(
+REACTPY_TESTING_DEFAULT_TIMEOUT = Option(
     "REACTPY_TESTING_DEFAULT_TIMEOUT",
     5.0,
     mutable=False,
diff --git a/src/py/reactpy/reactpy/core/serve.py b/src/py/reactpy/reactpy/core/serve.py
index 61a7e4ce6..bee7283d9 100644
--- a/src/py/reactpy/reactpy/core/serve.py
+++ b/src/py/reactpy/reactpy/core/serve.py
@@ -7,6 +7,7 @@
 from anyio import create_task_group
 from anyio.abc import TaskGroup
 
+from reactpy.config import REACTPY_DEBUG_MODE
 from reactpy.core.types import LayoutEventMessage, LayoutType, LayoutUpdateMessage
 
 logger = getLogger(__name__)
@@ -49,7 +50,18 @@ async def _single_outgoing_loop(
     layout: LayoutType[LayoutUpdateMessage, LayoutEventMessage], send: SendCoroutine
 ) -> None:
     while True:
-        await send(await layout.render())
+        update = await layout.render()
+        try:
+            await send(update)
+        except Exception:
+            if not REACTPY_DEBUG_MODE.current:
+                msg = (
+                    "Failed to send update. More info may be available "
+                    "if you enabling debug mode by settings "
+                    "`reactpy.config.REACTPY_DEBUG_MODE.current = True`."
+                )
+                logger.error(msg)
+            raise
 
 
 async def _single_incoming_loop(
diff --git a/src/py/reactpy/reactpy/core/vdom.py b/src/py/reactpy/reactpy/core/vdom.py
index 0548c6afc..32eeca485 100644
--- a/src/py/reactpy/reactpy/core/vdom.py
+++ b/src/py/reactpy/reactpy/core/vdom.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import json
 import logging
 from collections.abc import Mapping, Sequence
 from functools import wraps
@@ -8,7 +9,7 @@
 from fastjsonschema import compile as compile_json_schema
 
 from reactpy._warnings import warn
-from reactpy.config import REACTPY_DEBUG_MODE
+from reactpy.config import REACTPY_CHECK_JSON_ATTRS, REACTPY_DEBUG_MODE
 from reactpy.core._f_back import f_module_name
 from reactpy.core.events import EventHandler, to_event_handler_function
 from reactpy.core.types import (
@@ -199,6 +200,8 @@ def vdom(
     attributes, event_handlers = separate_attributes_and_event_handlers(attributes)
 
     if attributes:
+        if REACTPY_CHECK_JSON_ATTRS.current:
+            json.dumps(attributes)
         model["attributes"] = attributes
 
     if children:
diff --git a/src/py/reactpy/tests/test__option.py b/src/py/reactpy/tests/test__option.py
index 63f2fada8..d6de3ed3f 100644
--- a/src/py/reactpy/tests/test__option.py
+++ b/src/py/reactpy/tests/test__option.py
@@ -3,7 +3,7 @@
 
 import pytest
 
-from reactpy._option import DeprecatedOption, Option
+from reactpy._option import Option, deprecate
 
 
 def test_option_repr():
@@ -33,7 +33,7 @@ def test_option_validator():
     opt.current = "0"
     assert opt.current is False
 
-    with pytest.raises(ValueError, match="invalid literal for int"):
+    with pytest.raises(ValueError, match="Invalid value"):
         opt.current = "not-an-int"
 
 
@@ -102,10 +102,29 @@ def test_option_subscribe():
 
 
 def test_deprecated_option():
-    opt = DeprecatedOption("is deprecated!", "A_FAKE_OPTION", None)
+    opt = deprecate(Option("A_FAKE_OPTION", None), "is deprecated!")
 
     with pytest.warns(DeprecationWarning, match="is deprecated!"):
         assert opt.current is None
 
     with pytest.warns(DeprecationWarning, match="is deprecated!"):
         opt.current = "something"
+
+
+def test_option_parent():
+    parent_opt = Option("A_FAKE_OPTION", "default-value", mutable=True)
+    child_opt = Option("A_FAKE_OPTION", parent=parent_opt)
+    assert child_opt.mutable
+    assert child_opt.current == "default-value"
+
+    parent_opt.current = "new-value"
+    assert child_opt.current == "new-value"
+
+
+def test_option_parent_child_must_be_mutable():
+    mut_parent_opt = Option("A_FAKE_OPTION", "default-value", mutable=True)
+    immu_parent_opt = Option("A_FAKE_OPTION", "default-value", mutable=False)
+    with pytest.raises(TypeError, match="must be mutable"):
+        Option("A_FAKE_OPTION", parent=mut_parent_opt, mutable=False)
+    with pytest.raises(TypeError, match="must be mutable"):
+        Option("A_FAKE_OPTION", parent=immu_parent_opt, mutable=None)
diff --git a/src/py/reactpy/tests/test_utils.py b/src/py/reactpy/tests/test_utils.py
index c71057f15..ca3080358 100644
--- a/src/py/reactpy/tests/test_utils.py
+++ b/src/py/reactpy/tests/test_utils.py
@@ -204,10 +204,6 @@ def test_del_html_body_transform():
             html.div(SOME_OBJECT),
             f"<div>{html_escape(str(SOME_OBJECT))}</div>",
         ),
-        (
-            html.div({"someAttribute": SOME_OBJECT}),
-            f'<div someattribute="{html_escape(str(SOME_OBJECT))}"></div>',
-        ),
         (
             html.div(
                 "hello", html.a({"href": "https://example.com"}, "example"), "world"

From 8e7fde2e24c3a17130817a67ac9c0ed9677436aa Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 7 Jun 2023 13:51:01 -0600
Subject: [PATCH 02/13] add more tests

---
 src/py/reactpy/reactpy/config.py     |  6 +++++-
 src/py/reactpy/tests/test__option.py |  7 +++++++
 src/py/reactpy/tests/test_config.py  | 24 ++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/py/reactpy/reactpy/config.py b/src/py/reactpy/reactpy/config.py
index a80031ef4..8371e6d08 100644
--- a/src/py/reactpy/reactpy/config.py
+++ b/src/py/reactpy/reactpy/config.py
@@ -3,6 +3,8 @@
 variables or, for those which allow it, a programmatic interface.
 """
 
+from __future__ import annotations
+
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
@@ -12,9 +14,11 @@
 FALSE_VALUES = {"false", "0"}
 
 
-def boolean(value: str | bool) -> bool:
+def boolean(value: str | bool | int) -> bool:
     if isinstance(value, bool):
         return value
+    elif isinstance(value, int):
+        return bool(value)
     elif not isinstance(value, str):
         raise TypeError(f"Expected str or bool, got {type(value).__name__}")
 
diff --git a/src/py/reactpy/tests/test__option.py b/src/py/reactpy/tests/test__option.py
index d6de3ed3f..9e7eefbc4 100644
--- a/src/py/reactpy/tests/test__option.py
+++ b/src/py/reactpy/tests/test__option.py
@@ -128,3 +128,10 @@ def test_option_parent_child_must_be_mutable():
         Option("A_FAKE_OPTION", parent=mut_parent_opt, mutable=False)
     with pytest.raises(TypeError, match="must be mutable"):
         Option("A_FAKE_OPTION", parent=immu_parent_opt, mutable=None)
+
+
+def test_no_default_or_parent():
+    with pytest.raises(
+        TypeError, match="must specify either a default value or a parent"
+    ):
+        Option("A_FAKE_OPTION")
diff --git a/src/py/reactpy/tests/test_config.py b/src/py/reactpy/tests/test_config.py
index ecbbb998c..3428c3e28 100644
--- a/src/py/reactpy/tests/test_config.py
+++ b/src/py/reactpy/tests/test_config.py
@@ -27,3 +27,27 @@ def test_reactpy_debug_mode_toggle():
     # just check that nothing breaks
     config.REACTPY_DEBUG_MODE.current = True
     config.REACTPY_DEBUG_MODE.current = False
+
+
+def test_boolean():
+    assert config.boolean(True) is True
+    assert config.boolean(False) is False
+    assert config.boolean(1) is True
+    assert config.boolean(0) is False
+    assert config.boolean("true") is True
+    assert config.boolean("false") is False
+    assert config.boolean("True") is True
+    assert config.boolean("False") is False
+    assert config.boolean("TRUE") is True
+    assert config.boolean("FALSE") is False
+    assert config.boolean("1") is True
+    assert config.boolean("0") is False
+
+    with pytest.raises(ValueError):
+        config.boolean("2")
+
+    with pytest.raises(ValueError):
+        config.boolean("")
+
+    with pytest.raises(TypeError):
+        config.boolean(None)

From 4e772f4fac386ca20cded4facc376d90627bcd4a Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Sat, 10 Jun 2023 12:18:40 -0600
Subject: [PATCH 03/13] no need to be clever - just inherit

---
 src/py/reactpy/reactpy/_option.py    | 14 +++++++-------
 src/py/reactpy/tests/test__option.py |  4 ++--
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/py/reactpy/reactpy/_option.py b/src/py/reactpy/reactpy/_option.py
index 5475fbb8e..9f5ccacfc 100644
--- a/src/py/reactpy/reactpy/_option.py
+++ b/src/py/reactpy/reactpy/_option.py
@@ -11,12 +11,6 @@
 UNDEFINED = cast(Any, object())
 
 
-def deprecate(option: Option[_O], message: str) -> Option[_O]:
-    option.__class__ = _DeprecatedOption
-    option._deprecation_message = message
-    return option
-
-
 class Option(Generic[_O]):
     """An option that can be set using an environment variable of the same name"""
 
@@ -138,7 +132,13 @@ def __repr__(self) -> str:
         return f"Option({self._name}={self.current!r})"
 
 
-class _DeprecatedOption(Option[_O]):  # nocov
+class DeprecatedOption(Option[_O]):
+    """An option that will warn when it is accessed"""
+
+    def __init__(self, *args: Any, message: str, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        self._deprecation_message = message
+
     @Option.current.getter  # type: ignore
     def current(self) -> _O:
         warn(self._deprecation_message, DeprecationWarning)
diff --git a/src/py/reactpy/tests/test__option.py b/src/py/reactpy/tests/test__option.py
index 9e7eefbc4..89b65f9d3 100644
--- a/src/py/reactpy/tests/test__option.py
+++ b/src/py/reactpy/tests/test__option.py
@@ -3,7 +3,7 @@
 
 import pytest
 
-from reactpy._option import Option, deprecate
+from reactpy._option import DeprecatedOption, Option
 
 
 def test_option_repr():
@@ -102,7 +102,7 @@ def test_option_subscribe():
 
 
 def test_deprecated_option():
-    opt = deprecate(Option("A_FAKE_OPTION", None), "is deprecated!")
+    opt = DeprecatedOption("A_FAKE_OPTION", None, message="is deprecated!")
 
     with pytest.warns(DeprecationWarning, match="is deprecated!"):
         assert opt.current is None

From 469fa68b285e5633db39694bccde05ee3c6f7be7 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Sun, 11 Jun 2023 16:22:24 -0600
Subject: [PATCH 04/13] fix tests

---
 src/py/reactpy/reactpy/_option.py    | 11 ++++++++++-
 src/py/reactpy/tests/test__option.py |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/py/reactpy/reactpy/_option.py b/src/py/reactpy/reactpy/_option.py
index 9f5ccacfc..09d0304a9 100644
--- a/src/py/reactpy/reactpy/_option.py
+++ b/src/py/reactpy/reactpy/_option.py
@@ -141,5 +141,14 @@ def __init__(self, *args: Any, message: str, **kwargs: Any) -> None:
 
     @Option.current.getter  # type: ignore
     def current(self) -> _O:
-        warn(self._deprecation_message, DeprecationWarning)
+        try:
+            # we access the current value during init to debug log it
+            # no need to warn unless it's actually used. since this attr
+            # is only set after super().__init__ is called, we can check
+            # for it to determine if it's being accessed by a user.
+            msg = self._deprecation_message
+        except AttributeError:
+            pass
+        else:
+            warn(msg, DeprecationWarning)
         return super().current
diff --git a/src/py/reactpy/tests/test__option.py b/src/py/reactpy/tests/test__option.py
index 89b65f9d3..929e17488 100644
--- a/src/py/reactpy/tests/test__option.py
+++ b/src/py/reactpy/tests/test__option.py
@@ -132,6 +132,6 @@ def test_option_parent_child_must_be_mutable():
 
 def test_no_default_or_parent():
     with pytest.raises(
-        TypeError, match="must specify either a default value or a parent"
+        TypeError, match="Must specify either a default or a parent option"
     ):
         Option("A_FAKE_OPTION")

From 6b00eb159ddeacec592c7c2bc95160864bc6dd66 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Sun, 11 Jun 2023 18:00:18 -0600
Subject: [PATCH 05/13] ignore missing cov

---
 src/py/reactpy/reactpy/core/serve.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/py/reactpy/reactpy/core/serve.py b/src/py/reactpy/reactpy/core/serve.py
index bee7283d9..7b218c558 100644
--- a/src/py/reactpy/reactpy/core/serve.py
+++ b/src/py/reactpy/reactpy/core/serve.py
@@ -53,7 +53,7 @@ async def _single_outgoing_loop(
         update = await layout.render()
         try:
             await send(update)
-        except Exception:
+        except Exception:  # nocov
             if not REACTPY_DEBUG_MODE.current:
                 msg = (
                     "Failed to send update. More info may be available "

From b46b2872c2348585b8deeb4643fb5c3f5f7c1d32 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 20:15:24 -0600
Subject: [PATCH 06/13] add test for non-json serializable attrs

---
 src/py/reactpy/reactpy/backend/_common.py    |  2 +-
 src/py/reactpy/reactpy/core/serve.py         |  2 +-
 src/py/reactpy/reactpy/core/vdom.py          | 10 +++-------
 src/py/reactpy/tests/test_core/test_hooks.py |  9 +++++++++
 4 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/py/reactpy/reactpy/backend/_common.py b/src/py/reactpy/reactpy/backend/_common.py
index 80b4eeee1..17983a033 100644
--- a/src/py/reactpy/reactpy/backend/_common.py
+++ b/src/py/reactpy/reactpy/backend/_common.py
@@ -114,7 +114,7 @@ def vdom_head_elements_to_html(head: Sequence[VdomDict] | VdomDict | str) -> str
             head = cast(VdomDict, {**head, "tagName": ""})
         return vdom_to_html(head)
     else:
-        return vdom_to_html(html._(head))
+        return vdom_to_html(html._(*head))
 
 
 @dataclass
diff --git a/src/py/reactpy/reactpy/core/serve.py b/src/py/reactpy/reactpy/core/serve.py
index 7b218c558..3a530e854 100644
--- a/src/py/reactpy/reactpy/core/serve.py
+++ b/src/py/reactpy/reactpy/core/serve.py
@@ -57,7 +57,7 @@ async def _single_outgoing_loop(
             if not REACTPY_DEBUG_MODE.current:
                 msg = (
                     "Failed to send update. More info may be available "
-                    "if you enabling debug mode by settings "
+                    "if you enabling debug mode by setting "
                     "`reactpy.config.REACTPY_DEBUG_MODE.current = True`."
                 )
                 logger.error(msg)
diff --git a/src/py/reactpy/reactpy/core/vdom.py b/src/py/reactpy/reactpy/core/vdom.py
index 32eeca485..a845d51b5 100644
--- a/src/py/reactpy/reactpy/core/vdom.py
+++ b/src/py/reactpy/reactpy/core/vdom.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import json
-import logging
 from collections.abc import Mapping, Sequence
 from functools import wraps
 from typing import Any, Protocol, cast, overload
@@ -26,9 +25,6 @@
     VdomJson,
 )
 
-logger = logging.getLogger()
-
-
 VDOM_JSON_SCHEMA = {
     "$schema": "http://json-schema.org/draft-07/schema",
     "$ref": "#/definitions/element",
@@ -328,18 +324,18 @@ def _is_single_child(value: Any) -> bool:
 
 def _validate_child_key_integrity(value: Any) -> None:
     if hasattr(value, "__iter__") and not hasattr(value, "__len__"):
-        logger.error(
+        warn(
             f"Did not verify key-path integrity of children in generator {value} "
             "- pass a sequence (i.e. list of finite length) in order to verify"
         )
     else:
         for child in value:
             if isinstance(child, ComponentType) and child.key is None:
-                logger.error(f"Key not specified for child in list {child}")
+                warn(f"Key not specified for child in list {child}")
             elif isinstance(child, Mapping) and "key" not in child:
                 # remove 'children' to reduce log spam
                 child_copy = {**child, "children": _EllipsisRepr()}
-                logger.error(f"Key not specified for child in list {child_copy}")
+                warn(f"Key not specified for child in list {child_copy}")
 
 
 class _CustomVdomDictConstructor(Protocol):
diff --git a/src/py/reactpy/tests/test_core/test_hooks.py b/src/py/reactpy/tests/test_core/test_hooks.py
index 453d07c99..7231794ad 100644
--- a/src/py/reactpy/tests/test_core/test_hooks.py
+++ b/src/py/reactpy/tests/test_core/test_hooks.py
@@ -1257,3 +1257,12 @@ def bad_effect():
             await layout.render()
             component_hook.latest.schedule_render()
             await layout.render()  # no error
+
+
+@pytest.mark.skipif(
+    not REACTPY_DEBUG_MODE.current,
+    reason="only check json serialization in debug mode",
+)
+def test_raise_for_non_json_attrs():
+    with pytest.raises(TypeError, match="JSON serializable"):
+        reactpy.html.div({"non_json_serializable_object": object()})

From de3a73319526fca5a68317f0640ffdb55ab83729 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 20:18:04 -0600
Subject: [PATCH 07/13] add changelog entry

---
 docs/source/about/changelog.rst | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/source/about/changelog.rst b/docs/source/about/changelog.rst
index f739ce980..62e7d47eb 100644
--- a/docs/source/about/changelog.rst
+++ b/docs/source/about/changelog.rst
@@ -23,7 +23,10 @@ more info, see the :ref:`Contributor Guide <Creating a Changelog Entry>`.
 Unreleased
 ----------
 
-No changes.
+**Fixed**
+
+- :issue:`930` - better traceback for JSON serialization errors (via :pull:`1008`)
+- :issue:`437` - explain that JS component attributes must be JSON (via :pull:`1008`)
 
 
 v1.0.0

From c18c4b8e55957fc169f52c7d7137d16ac5143f8b Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 21:02:52 -0600
Subject: [PATCH 08/13] fix tests

---
 src/py/reactpy/reactpy/core/vdom.py          |  4 +-
 src/py/reactpy/tests/test_core/test_hooks.py |  9 ----
 src/py/reactpy/tests/test_core/test_vdom.py  | 44 ++++++++++++--------
 3 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/src/py/reactpy/reactpy/core/vdom.py b/src/py/reactpy/reactpy/core/vdom.py
index a845d51b5..840a09c7c 100644
--- a/src/py/reactpy/reactpy/core/vdom.py
+++ b/src/py/reactpy/reactpy/core/vdom.py
@@ -331,11 +331,11 @@ def _validate_child_key_integrity(value: Any) -> None:
     else:
         for child in value:
             if isinstance(child, ComponentType) and child.key is None:
-                warn(f"Key not specified for child in list {child}")
+                warn(f"Key not specified for child in list {child}", UserWarning)
             elif isinstance(child, Mapping) and "key" not in child:
                 # remove 'children' to reduce log spam
                 child_copy = {**child, "children": _EllipsisRepr()}
-                warn(f"Key not specified for child in list {child_copy}")
+                warn(f"Key not specified for child in list {child_copy}", UserWarning)
 
 
 class _CustomVdomDictConstructor(Protocol):
diff --git a/src/py/reactpy/tests/test_core/test_hooks.py b/src/py/reactpy/tests/test_core/test_hooks.py
index 7231794ad..453d07c99 100644
--- a/src/py/reactpy/tests/test_core/test_hooks.py
+++ b/src/py/reactpy/tests/test_core/test_hooks.py
@@ -1257,12 +1257,3 @@ def bad_effect():
             await layout.render()
             component_hook.latest.schedule_render()
             await layout.render()  # no error
-
-
-@pytest.mark.skipif(
-    not REACTPY_DEBUG_MODE.current,
-    reason="only check json serialization in debug mode",
-)
-def test_raise_for_non_json_attrs():
-    with pytest.raises(TypeError, match="JSON serializable"):
-        reactpy.html.div({"non_json_serializable_object": object()})
diff --git a/src/py/reactpy/tests/test_core/test_vdom.py b/src/py/reactpy/tests/test_core/test_vdom.py
index 76e26e46f..37abad1d2 100644
--- a/src/py/reactpy/tests/test_core/test_vdom.py
+++ b/src/py/reactpy/tests/test_core/test_vdom.py
@@ -280,28 +280,36 @@ def test_invalid_vdom(value, error_message_pattern):
         validate_vdom_json(value)
 
 
-@pytest.mark.skipif(not REACTPY_DEBUG_MODE.current, reason="Only logs in debug mode")
-def test_debug_log_cannot_verify_keypath_for_genereators(caplog):
-    reactpy.vdom("div", (1 for i in range(10)))
-    assert len(caplog.records) == 1
-    assert caplog.records[0].message.startswith(
-        "Did not verify key-path integrity of children in generator"
-    )
-    caplog.records.clear()
-
+@pytest.mark.skipif(not REACTPY_DEBUG_MODE.current, reason="Only warns in debug mode")
+def test_warn_cannot_verify_keypath_for_genereators():
+    with pytest.warns(UserWarning) as record:
+        reactpy.vdom("div", (1 for i in range(10)))
+        assert len(record) == 1
+        assert (
+            record[0]
+            .message.args[0]
+            .startswith("Did not verify key-path integrity of children in generator")
+        )
 
-@pytest.mark.skipif(not REACTPY_DEBUG_MODE.current, reason="Only logs in debug mode")
-def test_debug_log_dynamic_children_must_have_keys(caplog):
-    reactpy.vdom("div", [reactpy.vdom("div")])
-    assert len(caplog.records) == 1
-    assert caplog.records[0].message.startswith("Key not specified for child")
 
-    caplog.records.clear()
+@pytest.mark.skipif(not REACTPY_DEBUG_MODE.current, reason="Only warns in debug mode")
+def test_warn_dynamic_children_must_have_keys():
+    with pytest.warns(UserWarning) as record:
+        reactpy.vdom("div", [reactpy.vdom("div")])
+        assert len(record) == 1
+        assert record[0].message.args[0].startswith("Key not specified for child")
 
     @reactpy.component
     def MyComponent():
         return reactpy.vdom("div")
 
-    reactpy.vdom("div", [MyComponent()])
-    assert len(caplog.records) == 1
-    assert caplog.records[0].message.startswith("Key not specified for child")
+    with pytest.warns(UserWarning) as record:
+        reactpy.vdom("div", [MyComponent()])
+        assert len(record) == 1
+        assert record[0].message.args[0].startswith("Key not specified for child")
+
+
+@pytest.mark.skipif(not REACTPY_DEBUG_MODE.current, reason="only checked in debug mode")
+def test_raise_for_non_json_attrs():
+    with pytest.raises(TypeError, match="JSON serializable"):
+        reactpy.html.div({"non_json_serializable_object": object()})

From f4aa5075c6a1b23476aceb991491ddc98e534893 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 21:24:03 -0600
Subject: [PATCH 09/13] try node 16?

https://github.com/nodesource/distributions#using-ubuntu-3
---
 docs/Dockerfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/Dockerfile b/docs/Dockerfile
index 76a8ad7ee..cc43d8f7b 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -4,7 +4,7 @@ WORKDIR /app/
 
 # Install NodeJS
 # --------------
-RUN curl -sL https://deb.nodesource.com/setup_14.x  | bash -
+RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash -
 RUN apt-get install -yq nodejs build-essential
 RUN npm install -g npm@8.5.0
 

From c3545097e35f8145ef95adc46a97e91cdf45ad2e Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 21:51:09 -0600
Subject: [PATCH 10/13] install npm explicitey

---
 docs/Dockerfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/Dockerfile b/docs/Dockerfile
index cc43d8f7b..452327e2d 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -5,7 +5,7 @@ WORKDIR /app/
 # Install NodeJS
 # --------------
 RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash -
-RUN apt-get install -yq nodejs build-essential
+RUN apt-get install -yq nodejs npm build-essential
 RUN npm install -g npm@8.5.0
 
 # Install Poetry

From aebbf875c5d171ed98f7fa851870a46091ca1d31 Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 21:53:32 -0600
Subject: [PATCH 11/13] try install in different order

---
 docs/Dockerfile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/Dockerfile b/docs/Dockerfile
index 452327e2d..176ac6c8f 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -4,8 +4,8 @@ WORKDIR /app/
 
 # Install NodeJS
 # --------------
-RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash -
-RUN apt-get install -yq nodejs npm build-essential
+RUN apt-get install -y build-essential
+RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - && apt-get install -y nodejs
 RUN npm install -g npm@8.5.0
 
 # Install Poetry

From d6c9718b57d82e24cacd2a165d4595ea123a185a Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 21:58:53 -0600
Subject: [PATCH 12/13] update first

---
 docs/Dockerfile | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/docs/Dockerfile b/docs/Dockerfile
index 176ac6c8f..95e91beb5 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -2,9 +2,13 @@ FROM python:3.9
 
 WORKDIR /app/
 
+# Misc Dependencies
+# -----------------
+RUN apt-get update
+RUN apt-get install -y build-essential
+
 # Install NodeJS
 # --------------
-RUN apt-get install -y build-essential
 RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - && apt-get install -y nodejs
 RUN npm install -g npm@8.5.0
 

From e83eb472ef17b7f91b808c6f9712abcf341000dd Mon Sep 17 00:00:00 2001
From: rmorshea <ryan.morshead@gmail.com>
Date: Wed, 14 Jun 2023 22:04:45 -0600
Subject: [PATCH 13/13] explicitely install npm i guess...

---
 docs/Dockerfile | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/docs/Dockerfile b/docs/Dockerfile
index 95e91beb5..39b9c51be 100644
--- a/docs/Dockerfile
+++ b/docs/Dockerfile
@@ -2,14 +2,10 @@ FROM python:3.9
 
 WORKDIR /app/
 
-# Misc Dependencies
-# -----------------
-RUN apt-get update
-RUN apt-get install -y build-essential
-
 # Install NodeJS
 # --------------
-RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - && apt-get install -y nodejs
+RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash -
+RUN apt-get install -y build-essential nodejs npm
 RUN npm install -g npm@8.5.0
 
 # Install Poetry