diff --git a/tests/functional2/testlib/commands.py b/tests/functional2/testlib/commands.py
index 7275c5e51..2f55afc6a 100644
--- a/tests/functional2/testlib/commands.py
+++ b/tests/functional2/testlib/commands.py
@@ -26,13 +26,7 @@ class CommandResult:
         assumes a return code of 0
         :raises CalledProcessError: if the return code wasn't 0 and logs the processes stdout and stderr
         """
-        if self.rc != 0:
-            logger.error("stdout: %s", self.stdout_s)
-            logger.error("stderr: %s", self.stderr_s)
-            raise subprocess.CalledProcessError(
-                returncode=self.rc, cmd=self.cmd, stderr=self.stderr, output=self.stdout
-            )
-        return self
+        return self.expect(0)
 
     def expect(self, rc: int) -> "CommandResult":
         """
@@ -104,8 +98,17 @@ class Command:
 
     def with_env(self, **kwargs) -> "Command":
         """
-        adds or updates environment and path variables
-        :param kwargs: new or updated variables
+        sets the env to the given environment variables
+        :param kwargs: keyword arguments containing the environment
+        :return: self, command is chainable
+        """
+        self.env = kwargs
+        return self
+
+    def update_env(self, **kwargs) -> "Command":
+        """
+        updates the current environment with the given dict of variables
+        :param kwargs: new or updated environment variables
         :return: self, command is chainable
         """
         self.env.update(kwargs)
diff --git a/tests/functional2/testlib/test_commands.py b/tests/functional2/testlib/test_commands.py
new file mode 100644
index 000000000..18a37917d
--- /dev/null
+++ b/tests/functional2/testlib/test_commands.py
@@ -0,0 +1,87 @@
+import logging
+import os
+import stat
+from pathlib import Path
+from subprocess import CalledProcessError
+
+import pytest
+from _pytest.logging import LogCaptureFixture
+from functional2.testlib.commands import Command
+from functional2.testlib.fixtures.file_helper import File
+
+
+def test_command_valid_runs():
+    cmd = Command(["echo", "water"]).with_env(**os.environ.copy())
+    cmd.run().ok()
+
+
+def test_command_captures_stdout():
+    cmd = Command(["echo", "fire"]).with_env(**os.environ.copy())
+    res = cmd.run().ok()
+    assert res.stdout_s == "fire\n"
+
+
+def test_command_plain_strips():
+    cmd = Command(["echo", "   earth   "]).with_env(**os.environ.copy())
+    res = cmd.run().ok()
+    assert res.stdout_plain == "earth"
+
+
+def test_command_stdin_passed_correctly():
+    inp = b"air"
+    cmd = Command(["cat", "/dev/stdin"]).with_stdin(inp).with_env(**os.environ.copy())
+    res = cmd.run().ok()
+    assert res.stdout == inp
+
+
+def test_command_expect_failure():
+    cmd = Command(["grep", "xxx"]).with_env(**os.environ.copy()).with_stdin(b"")
+    cmd.run().expect(1)
+
+
+@pytest.mark.parametrize(
+    "files",
+    [
+        {
+            "script.sh": File(
+                "#!/bin/sh\necho forb\nexit 1", mode=stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO
+            )
+        }
+    ],
+    indirect=True,
+)
+def test_command_ok_fails_on_bad_exit_code(files: Path, caplog: LogCaptureFixture):
+    cmd = Command(["./script.sh"], cwd=files).with_env(**os.environ.copy())
+    res = cmd.run()
+
+    with pytest.raises(CalledProcessError), caplog.at_level(logging.ERROR):
+        res.ok()
+    msgs = caplog.messages
+    assert len(msgs) == 2
+    out_msg, err_msg = msgs
+    assert out_msg == "stdout: forb\n"
+    assert err_msg == "stderr: "
+
+
+@pytest.mark.parametrize(
+    "files",
+    [
+        {
+            "script.sh": File(
+                "#!/bin/sh\necho drgn fops\nexit 2", mode=stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO
+            )
+        }
+    ],
+    indirect=True,
+)
+def test_command_exec_fails_on_other_bad_exit_code(files: Path, caplog: LogCaptureFixture):
+    cmd = Command(["./script.sh"], cwd=files).with_env(**os.environ.copy())
+    res = cmd.run()
+
+    with pytest.raises(CalledProcessError), caplog.at_level(logging.ERROR):
+        res.expect(1)
+    msgs = caplog.messages
+    assert len(msgs) == 2
+    out_msg, err_msg = msgs
+    assert out_msg == "stdout: drgn fops\n"
+    assert err_msg == "stderr: "