test_local.py and test_exec_command_failure__expect_error are added

test_local.py contains set of test for LocalOperations
 - test_exec_command_success
 - test_exec_command_failure
 - test_exec_command_failure__expect_error

Changes in TestRemoteOperations:
 - test_exec_command_failure exptects an exception
 - new test test_exec_command_failure__expect_error was added

TestRemoteOperations::test_exec_command_failure__expect_error will fail because RemoteOperations::exec_command does not handle the 'expect_error' parameter correctly.

tests/test_local.py

@@ -0,0 +1,46 @@
+import pytest
+
+from testgres import ExecUtilException
+from testgres import LocalOperations
+
+
+class TestLocalOperations:
+
+    @pytest.fixture(scope="function", autouse=True)
+    def setup(self):
+        self.operations = LocalOperations()
+
+    def test_exec_command_success(self):
+        """
+        Test exec_command for successful command execution.
+        """
+        cmd = "python3 --version"
+        response = self.operations.exec_command(cmd, wait_exit=True, shell=True)
+
+        assert b'Python 3.' in response
+
+    def test_exec_command_failure(self):
+        """
+        Test exec_command for command execution failure.
+        """
+        cmd = "nonexistent_command"
+        while True:
+            try:
+                self.operations.exec_command(cmd, wait_exit=True, shell=True)
+            except ExecUtilException as e:
+                error = e.message
+                break
+            raise Exception("We wait an exception!")
+        assert error == "Utility exited with non-zero code. Error `b'/bin/sh: 1: nonexistent_command: not found\\n'`"
+
+    def test_exec_command_failure__expect_error(self):
+        """
+        Test exec_command for command execution failure.
+        """
+        cmd = "nonexistent_command"
+
+        exit_status, result, error = self.operations.exec_command(cmd, verbose=True, wait_exit=True, shell=True, expect_error=True)
+
+        assert error == b'/bin/sh: 1: nonexistent_command: not found\n'
+        assert exit_status == 127
+        assert result == b''

tests/test_remote.py

@@ -30,12 +30,27 @@ def test_exec_command_failure(self):
         Test exec_command for command execution failure.
         """
         cmd = "nonexistent_command"
-        try:
-            exit_status, result, error = self.operations.exec_command(cmd, verbose=True, wait_exit=True)
-        except ExecUtilException as e:
-            error = e.message
+        while True:
+            try:
+                self.operations.exec_command(cmd, verbose=True, wait_exit=True)
+            except ExecUtilException as e:
+                error = e.message
+                break
+            raise Exception("We wait an exception!")
         assert error == b'Utility exited with non-zero code. Error: bash: line 1: nonexistent_command: command not found\n'
 
+    def test_exec_command_failure__expect_error(self):
+        """
+        Test exec_command for command execution failure.
+        """
+        cmd = "nonexistent_command"
+
+        exit_status, result, error = self.operations.exec_command(cmd, verbose=True, wait_exit=True, shell=True, expect_error=True)
+
+        assert error == b'bash: line 1: nonexistent_command: command not found\n'
+        assert exit_status == 127
+        assert result == b''
+
     def test_is_executable_true(self):
         """
         Test is_executable for an existing executable.