selftest: contrib: Add some GDB startup tests

These tests should catch a couple of edge-cases of GDB startup where
tbot is supposed to properly throw a certain exception.

Signed-off-by: Harald Seiler <[email protected]>

selftest/tests/contrib/test_gdb.py

@@ -1,14 +1,48 @@
 import re
+from typing import Tuple, Type
 
 import pytest
 import testmachines
 
 import tbot
 import tbot_contrib.gdb
+from tbot.machine import linux
 
 RESULT_PATTERN = re.compile(r"\$\d+ = 0x[0-9a-f]+ (?:<.*> )?\"(.*)\"")
 
 
+@pytest.mark.parametrize(  # type: ignore
+    "failure_mode",
+    [
+        ("true", linux.CommandEndedException),
+        ("false", tbot.error.CommandFailure),
+    ],
+    ids=lambda failure_mode: failure_mode[1].__name__,
+)
+def test_gdb_start_crash(
+    tbot_context: tbot.Context, failure_mode: Tuple[str, Type[Exception]]
+) -> None:
+    command, exception = failure_mode
+    with tbot_context.request(testmachines.Localhost) as lh:
+        with pytest.raises(exception):
+            # Run `echo` instead of GDB to force an initialization error
+            with tbot_contrib.gdb.GDB(lh, gdb=command) as gdb:
+                gdb.exec("help")
+
+        lh.exec0("uname", "-r")
+
+
+def test_gdb_init_hang(tbot_context: tbot.Context) -> None:
+    with tbot_context.request(testmachines.Localhost) as lh:
+        with pytest.raises(TimeoutError):
+            # Run `echo` instead of GDB to force and hack in a sleep
+            # to let the initialization hang forever
+            with tbot_contrib.gdb.GDB(lh, linux.Then, "sleep", "30", gdb="echo") as gdb:  # type: ignore
+                gdb.exec("help")
+
+        lh.exec0("uname", "-r")
+
+
 def test_gdb_machine(tbot_context: tbot.Context) -> None:
     with tbot_context.request(testmachines.Localhost) as lh:
         program = lh.exec0("which", "echo").strip()