Implement basic version of local shell

Also added two simple reporters that can be used by the shell to report command execution details.

Signed-off-by: Vladimir Domnich <v.domnich@yadro.com>

tests/helpers.py

@@ -0,0 +1,9 @@
+import traceback
+
+
+def format_error_details(error: Exception) -> str:
+    return "".join(traceback.format_exception(
+        etype=type(error),
+        value=error,
+        tb=error.__traceback__)
+    )

tests/test_local_shell_interactive.py

@@ -0,0 +1,78 @@
+from unittest import TestCase
+
+from shell.interfaces import CommandOptions, InteractiveInput
+from shell.local_shell import LocalShell
+from tests.helpers import format_error_details
+
+
+class TestLocalShellInteractive(TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.shell = LocalShell()
+
+    def test_command_with_one_prompt(self):
+        script = "password = input('Password: '); print(password)"
+
+        inputs = [InteractiveInput(prompt_pattern="Password", input="test")]
+        result = self.shell.exec(
+            f"python -c \"{script}\"",
+            CommandOptions(interactive_inputs=inputs)
+        )
+
+        self.assertEqual(0, result.return_code)
+        self.assertOutputLines(["Password: test", "test"], result.stdout)
+        self.assertEqual("", result.stderr)
+
+    def test_command_with_several_prompts(self):
+        script = (
+            "input1 = input('Input1: '); print(input1); "
+            "input2 = input('Input2: '); print(input2)"
+        )
+        inputs = [
+            InteractiveInput(prompt_pattern="Input1", input="test1"),
+            InteractiveInput(prompt_pattern="Input2", input="test2"),
+        ]
+
+        result = self.shell.exec(
+            f"python -c \"{script}\"",
+            CommandOptions(interactive_inputs=inputs)
+        )
+
+        self.assertEqual(0, result.return_code)
+        self.assertOutputLines(["Input1: test1", "test1", "Input2: test2", "test2"], result.stdout)
+        self.assertEqual("", result.stderr)
+
+    def test_failed_command_with_check(self):
+        script = "invalid script"
+        inputs = [InteractiveInput(prompt_pattern=".*", input="test")]
+
+        with self.assertRaises(RuntimeError) as exc:
+            self.shell.exec(f"python -c \"{script}\"", CommandOptions(interactive_inputs=inputs))
+
+        error = format_error_details(exc.exception)
+        self.assertIn("Error", error)
+        # TODO: it would be nice to have return code as well
+        # self.assertIn("return code: 1", error)
+
+    def test_failed_command_without_check(self):
+        script = "invalid script"
+        inputs = [InteractiveInput(prompt_pattern=".*", input="test")]
+
+        result = self.shell.exec(
+            f"python -c \"{script}\"",
+            CommandOptions(interactive_inputs=inputs, check=False),
+        )
+        self.assertEqual(1, result.return_code)
+
+    def test_non_existing_binary(self):
+        inputs = [InteractiveInput(prompt_pattern=".*", input="test")]
+
+        with self.assertRaises(RuntimeError) as exc:
+            self.shell.exec("not-a-command", CommandOptions(interactive_inputs=inputs))
+
+        error = format_error_details(exc.exception)
+        self.assertIn("command was not found or was not executable", error)
+
+    def assertOutputLines(self, expected_lines: list[str], output: str) -> None:
+        output_lines = [line.strip() for line in output.split("\n") if line.strip()]
+        self.assertEqual(expected_lines, output_lines)

tests/test_local_shell_non_interactive.py

@@ -0,0 +1,46 @@
+from unittest import TestCase
+
+from shell.interfaces import CommandOptions
+from shell.local_shell import LocalShell
+from tests.helpers import format_error_details
+
+
+class TestLocalShellNonInteractive(TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.shell = LocalShell()
+
+    def test_successful_command(self):
+        script = "print('test')"
+
+        result = self.shell.exec(f"python -c \"{script}\"")
+
+        self.assertEqual(0, result.return_code)
+        self.assertEqual("test", result.stdout.strip())
+        self.assertEqual("", result.stderr)
+
+    def test_failed_command_with_check(self):
+        script = "invalid script"
+
+        with self.assertRaises(RuntimeError) as exc:
+            self.shell.exec(f"python -c \"{script}\"")
+
+        error = format_error_details(exc.exception)
+        self.assertIn("Error", error)
+        self.assertIn("return code: 1", error)
+
+    def test_failed_command_without_check(self):
+        script = "invalid script"
+
+        result = self.shell.exec(f"python -c \"{script}\"", CommandOptions(check=False))
+
+        self.assertEqual(1, result.return_code)
+        self.assertIn("Error", result.stdout)
+
+    def test_non_existing_binary(self):
+        with self.assertRaises(RuntimeError) as exc:
+            self.shell.exec(f"not-a-command")
+
+        error = format_error_details(exc.exception)
+        self.assertIn("Error", error)
+        self.assertIn("return code: 127", error)