Set a diff `Msg.pld` spec per test and then send multiple types to
a child actor making sure the child can only send certain types over
a stream and fails with validation or decode errors ow. The test is also
param-ed both with and without hooks demonstrating how a custom type,
`NamespacePath`, needs them for effective use. The subactor IPC context
child is passed a `expect_ipc_send: dict` which relays the values along
with their expected `.send()`-ability.
Deats on technical refinements:
------ - ------
- added a `iter_maybe_sends()` send-value-as-msg-auditor and predicate
generator (literally) so as to be able to pre-determine if given the
current codec and `send_values` which values are expected to be IPC
transmittable.
- as per ^, the diff value-msgs are first round-tripped inside
a `Started` msg using the configured codec in the parent/root actor
before bothering with using IPC primitives + a subactor; this is how
the `expect_ipc_send` table is generated initially.
- for serializing the specs (`Union[Type]`s as required by `msgspec`),
added a pair of codec hooks: `enc/dec_type_union()` (that ideally we
move into a `.msg` submod eventually) which code the type-values as
a `list[str]` of names.
- the `dec_` hook had to be modified to NOT raise an error when an
invalid/unhandled value arrives, this is because we do NOT want the
RPC msg handling loop to raise on the `async for msg in chan:` and
instead prefer to ignore and warn (for now, but eventually respond
with error msg - see notes in hook body) these msgs when sent during
a streaming phase; `Context.started()` will however error on a bad
input for the current msg-spec since it is part of the "cheap"
dialog (again see notes in `._context`) wherein the `Started` msg
is always roundtripped prior to `Channel.send()` to guarantee
the child adheres to its own spec.
- tossed in lotsa `print()`s for console groking of the run progress.
Further notes on typed-msging breaking cancellation:
------ - ------
- turns out since the runtime's cancellation implementation, being done
with `Actor.cancel()` methods and friends will actually break when
a stringent spec is applied (eg. a single type-spec) since the return
values from said methods are generally `bool`s..
- this means we do indeed need special handling of "runtime RPC method
invocations" since ideally a user's msg-spec choices do not break core
functionality on them XD
=> The obvi solution is to add a/some special sub-`Msg` types for such
cases, possibly just a `RuntimeReturn(Return)` type that will always
include a `.pld: bool` for these cancel methods such that their
results are always handled without msg type errors.
More to come on a (hopefully) elegant solution to that last bit!
Though the runtime hasn't been changed over in this patch (it was in the
local index at the time however), the test does now demonstrate that
using a `Started` the correctly typed `.pld` will codec correctly when
passed manually to `MsgCodec.encode/decode()`.
Despite not having the runtime ported to the new shuttle msg set
(meaning the mentioned test will fail without the runtime port patch),
I was able to get this first original test working that limits payload
packets as a `Msg.pld: NamespacePath`this as long as we spec
`enc/dec_hook()`s then the `Msg.pld` will be processed correctly as per:
https://jcristharif.com/msgspec/extending.html#mapping-to-from-native-types
in both the `Any` and `NamespacePath|None` spec cases.
^- turns out in this case -^ that the codec hooks only get invoked on
the unknown-fields NOT the entire `Struct`-msg.
A further gotcha was merging a `|None` into the `pld_spec` since this
test spawns a subactor and opens a context via `send_back_nsp()` and
that func has no explicit `return` - so of course it delivers
a `Return(pld=None)` which will fail if we only spec `NamespacePath`.
Turns out the generics based payload speccing API, as in
https://jcristharif.com/msgspec/supported-types.html#generic-types,
DOES WORK properly as long as we don't rely on inheritance from `Msg`
a parent `Generic`..
So let's get real pedantic in the `mk_msg_spec()` internals as well as
verification in the test suite!
Fixes in `.msg.types`:
- implement (as part of tinker testing) multiple spec union building
methods via a `spec_build_method: str` to `mk_msg_spec()` and leave a
buncha notes around what did and didn't work:
- 'indexed_generics' is the only method THAT WORKS and the one that
you'd expect being closest to the `msgspec` docs (link above).
- 'defstruct' using dynamically defined msgs => doesn't work!
- 'types_new_class' using dynamically defined msgs but with
`types.new_clas()` => ALSO doesn't work..
- explicitly separate the `.pld` type-constrainable by user code msg
set into `types._payload_spec_msgs` putting the others in
a `types._runtime_spec_msgs` and the full set defined as `.__spec__`
(moving it out of the pkg-mod and back to `.types` as well).
- for the `_payload_spec_msgs` msgs manually make them inherit `Generic[PayloadT]`
and (redunantly) define a `.pld: PayloadT` field.
- make `IpcCtxSpec.functype` an in line `Literal`.
- toss in some TODO notes about choosing a better `Msg.cid` type.
Fixes/tweaks around `.msg._codec`:
- rename `MsgCodec.ipc/pld_msg_spec` -> `.msg/pld_spec`
- make `._enc/._dec` non optional fields
- wow, ^facepalm^ , make sure `._ipc.MsgpackTCPStream.__init__()` uses
`mk_codec()` since `MsgCodec` can't be (easily) constructed directly.
Get more detailed in testing:
- inside the `chk_pld_type()` helper ensure `roundtrip` is always set to
some value, `None` by default but a bool depending on legit outcome.
- drop input `generic`; no longer used.
- drop the masked `typedef` loop from `Msg.__subclasses__()`.
- for add an `expect_roundtrip: bool` and use to jump into debugger
when any expectation doesn't match the outcome.
- use new `MsgCodec` field names (as per first section above).
- ensure the encoded msg matches the decoded one from both the ad-hoc
decoder and codec loaded values.
- ensure the pld checking is only applied to msgs in the
`types._payload_spec_msgs` set by `typef.__name__` filtering
since `mk_msg_spec()` now returns the full `.types.Msg` set.
Mostly adjusting input args/logic to various spec/codec signatures and
new runtime semantics:
- `test_msg_spec_xor_pld_spec()` to verify that a shuttle prot spec and
payload spec are necessarily mutex and that `mk_codec()` enforces it.
- switch to `ipc_msg_spec` input in `mk_custom_codec()` helper.
- drop buncha commented cruft from `test_limit_msgspec()` including no
longer needed type union instance checks in dunder attributes.
Tyler Goodlet