Fix Azure Functions E2E log framing and host isolation

noxfile.py

@@ -493,9 +493,6 @@ def functions_e2e(session: nox.Session) -> None:
         ),
     )
     try:
-        session.env[
-            "AzureFunctionsJobHost__extensions__durableTask__hubName"
-        ] = _new_test_namespace("nox")
         session.env["E2E_PAYLOAD_CONTAINER"] = _new_test_namespace("payloads")
         session.install("-r", "requirements.txt")
         _install_packages(session, editable=True)

tests/azure-functions-durable/e2e/_harness.py

@@ -16,6 +16,7 @@
 
 import json
 import os
+import re
 import shutil
 import signal
 import socket
@@ -259,7 +260,8 @@ class FunctionApp:
 
     Use as a context manager. On entry it starts the host and blocks until the
     app's ``/api/ping`` route responds; on exit it terminates the whole process
-    group and surfaces the captured host log if startup failed.
+    group and surfaces the captured host log if startup failed. Each instance
+    uses a unique task hub so sample hosts cannot consume each other's work.
     """
 
     # ``func start`` binds the HTTP port itself, some time after we pick a free
@@ -274,6 +276,7 @@ def __init__(self, app_name: str, port: Optional[int] = None):
             raise FileNotFoundError(f"Sample app not found: {self.app_dir}")
         self.port = port or find_free_port()
         self.base_url = f"http://127.0.0.1:{self.port}"
+        self._task_hub_name = f"e2e{uuid.uuid4().hex}"
         self._process: Optional[subprocess.Popen[str]] = None
         self._log_path = self.app_dir / "_func_host.log"
 
@@ -331,6 +334,7 @@ def start(self) -> None:
 
     def _build_env(self) -> dict[str, str]:
         env = os.environ.copy()
+        env["AzureFunctionsJobHost__extensions__durableTask__hubName"] = self._task_hub_name
         # Start the host exactly as a developer would after activating the
         # app's OWN virtual environment (``<app>/.venv``). The environment MUST
         # live inside the app directory: the Functions Python worker only
@@ -416,7 +420,7 @@ def read_host_log(self) -> str:
         return self._read_log()
 
     def wait_for_host_log(self, text: str, timeout: float = 30) -> str:
-        """Wait until captured Functions host output contains ``text``."""
+        """Wait for ``text`` and return its host record, not its physical line."""
         deadline = time.time() + timeout
         log = self._read_log()
         while text not in log and time.time() < deadline:
@@ -426,7 +430,16 @@ def wait_for_host_log(self, text: str, timeout: float = 30) -> str:
             raise TimeoutError(
                 f"Functions host log did not contain {text!r} within {timeout}s.\n"
                 f"{log}")
-        return next(line for line in log.splitlines() if text in line)
+        # Host stdout/stderr can concatenate timestamped records without a newline.
+        return next(
+            record
+            for line in log.splitlines()
+            for record in re.split(
+                r"(?=\[\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d+)?Z\] )",
+                line,
+            )
+            if text in record
+        )
 
     def stop(self) -> None:
         proc = self._process

tests/azure-functions-durable/e2e/test_host_isolation.py

@@ -0,0 +1,28 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+import os
+import re
+
+import pytest
+
+from ._harness import FunctionApp
+
+
+def test_sample_hosts_use_independent_task_hubs(monkeypatch: pytest.MonkeyPatch) -> None:
+    setting = "AzureFunctionsJobHost__extensions__durableTask__hubName"
+    monkeypatch.setenv(setting, "sharedhub")
+    apps = [FunctionApp(name) for name in (
+        "v1_style", "dtask_style", "tracing", "v1_style")]
+    environments = [
+        app._build_env()  # pyright: ignore[reportPrivateUsage]
+        for app in apps
+    ]
+    task_hubs = [env[setting] for env in environments]
+
+    assert len(set(task_hubs)) == len(apps)
+    assert all(re.fullmatch(r"[A-Za-z][A-Za-z0-9]{2,49}", hub) for hub in task_hubs)
+    assert "sharedhub" not in task_hubs
+    assert os.environ[setting] == "sharedhub"
+    for app, env in zip(apps, environments):
+        assert app._build_env()[setting] == env[setting]  # pyright: ignore[reportPrivateUsage]

tests/azure-functions-durable/e2e/test_host_log_records.py

@@ -0,0 +1,57 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+from pathlib import Path
+
+import pytest
+
+from ._harness import FunctionApp
+
+
+@pytest.mark.parametrize("message", [
+    "Starting new 'activity_chain' instance with ID = 'test-instance'.",
+    "test-instance: Orchestration activity_chain completed with status: COMPLETED",
+])
+@pytest.mark.parametrize(("before", "after"), [
+    ("", ""),
+    ("", "[2026-11-02T19:42:58.870Z] Request GET http://127.0.0.1:10002/"),
+    ("[2026-11-02T19:42:58.869Z] Previous record", ""),
+    ("[2026-11-02T19:42:58.869Z] Previous record",
+     "[2026-11-02T19:42:58.871Z] Next record"),
+    ("[2026-11-02T19:42:58Z] Previous record",
+     "[2026-11-02T19:42:58.8701234Z] Next record"),
+    ("[2026-11-02T19:42:58.869Z] Previous record\n",
+     "\n[2026-11-02T19:42:58.871Z] Next record"),
+    ("[2026-11-02T19:42:58.869Z] Previous record\r\n",
+     "\r\n[2026-11-02T19:42:58.871Z] Next record"),
+])
+def test_wait_for_host_log_extracts_timestamped_record(
+        tmp_path: Path, monkeypatch: pytest.MonkeyPatch,
+        message: str, before: str, after: str) -> None:
+    app = FunctionApp("dtask_style")
+    log_path = tmp_path / "host.log"
+    monkeypatch.setattr(app, "_log_path", log_path)
+    expected = f"[2026-11-02T19:42:58.870Z] {message}"
+    log_path.write_text(before + expected + after, encoding="utf-8")
+
+    record = app.wait_for_host_log(message, timeout=0)
+
+    assert record == expected
+
+
+@pytest.mark.parametrize("output", [
+    "SDK message",
+    "[2026-11-02T19:42:58.870Z]\nSDK message",
+    "[2026-11-02T19:42:58.870Z] Unrelated record SDK message",
+    "[2026-11-02T19:42:58.870Z] SDK message unexpected suffix",
+])
+def test_wait_for_host_log_preserves_nonmatching_records(
+        tmp_path: Path, monkeypatch: pytest.MonkeyPatch, output: str) -> None:
+    app = FunctionApp("dtask_style")
+    log_path = tmp_path / "host.log"
+    monkeypatch.setattr(app, "_log_path", log_path)
+    log_path.write_text(output, encoding="utf-8")
+
+    record = app.wait_for_host_log("SDK message", timeout=0)
+
+    assert record == output.splitlines()[-1]

tests/azure-functions-durable/e2e/test_v1_client_e2e.py

@@ -6,8 +6,7 @@
 Covers ``suspend``/``resume``, ``restart``, ``get_status_all``,
 ``get_status_by``, ``purge_instance_history_by``,
 ``create_http_management_payload`` / ``get_client_response_links``,
-``wait_for_completion_or_create_check_status_response``, and the ``rewind``
-NotImplementedError stub.
+``wait_for_completion_or_create_check_status_response``, and ``rewind``.
 """
 
 from datetime import datetime, timedelta, timezone
@@ -110,6 +109,7 @@ def test_rewind(v1_app):
     instance_id = v1_app.start_orchestration("rewind_target")
     failed = v1_app.wait_for_completion(instance_id)
     assert failed["runtimeStatus"] == "Failed"
+    assert "failing on first attempt (rewind to retry)" in failed["output"]
 
     result = http_request("POST", f"{v1_app.base_url}/api/rewind/{instance_id}")
     assert result.status == 202