Make kernel integration tests deterministic

DEV.md

@@ -92,8 +92,10 @@ The Python wrapper may place a standalone kernel in its own process group. On sh
 - a pure Rust echo language, implemented entirely in the example binary, through the crate API;
 - an IPython shell through the Python adapter.
 
-Standalone Rust tests cover wire framing and language interruption primitives. A Python integration test drives a real debugpy session through the DAP
-transport. ipymini's complete protocol and behavior suite is kernmini's main integration test.
+`ConKernelClient` launches each kernel and manages its Jupyter requests, replies, IOPub messages, stdin, and shutdown. Tests use live protocol events to
+synchronize concurrent behavior rather than sleeps or hand-written socket draining. Standalone Rust tests cover wire framing and language interruption
+primitives. A Python integration test drives a real debugpy session through the DAP transport directly, since that transport is the subject of the test.
+ipymini's complete protocol and behavior suite is kernmini's main integration test.
 
 ```bash
 cd ../ipymini

pyproject.toml

@@ -19,6 +19,7 @@ dependencies = ["fastcore>=2.2.17"]
 
 [project.optional-dependencies]
 dev = [
+  "conkernelclient>=0.0.23",
   "debugpy>=1.8.21",
   "fastship>=0.0.11",
   "ipymini>=0.1.20",

tests/echo_kernel.py

@@ -0,0 +1,31 @@
+"The minimal Python language adapter used by kernmini's client-driven tests."
+
+import sys
+from contextlib import contextmanager
+
+from kernmini import run_kernel
+
+
+class EchoShell:
+    def __init__(self, request_input=None, **kw): self.execution_count,self._stream = 0,None
+    def set_stream_sender(self, sender): self._stream = sender
+
+    @contextmanager
+    def execution_context(self, allow_stdin, silent): yield
+
+    def kernel_info(self):
+        return dict(implementation="echokernel", implementation_version="0.0.1", banner="echo",
+            language_info=dict(name="echo", version="1.0", mimetype="text/plain", file_extension=".txt"))
+
+    async def execute(self, code, silent=False, store_history=True, user_expressions=None, allow_stdin=False):
+        self.execution_count += 1
+        if self._stream: self._stream("stdout", f"echo: {code}\n")
+        if code.startswith("sleep:"):
+            import asyncio
+            await asyncio.sleep(float(code[6:]))
+        if code == "boom": return dict(execution_count=self.execution_count, error=dict(ename="EchoError", evalue=code, traceback=[]))
+        if code == "bytes": return dict(execution_count=self.execution_count, result={"image/png": b"raw"})
+        return dict(execution_count=self.execution_count, result={"text/plain": code.upper()})
+
+
+if __name__ == "__main__": run_kernel(sys.argv[-1], EchoShell)

tests/ipython_kernel.py

@@ -0,0 +1,20 @@
+"The real ipymini language adapter hosted directly by kernmini."
+
+import asyncio, sys
+
+from ipymini.shell import MiniShell
+from kernmini._native import run_kernel
+
+
+async def main():
+    user_ns, first = {}, True
+    def shell_factory():
+        nonlocal first
+        shell = MiniShell(request_input=lambda *_: "", user_ns=user_ns, use_singleton=first)
+        first = False
+        return shell
+    await run_kernel(sys.argv[-1], shell_factory, asyncio.new_event_loop)
+
+
+if __name__ == "__main__":
+    with asyncio.Runner() as runner: runner.run(main())