test(daytona): add unit and integration tests for Daytona backend

Unit tests cover cwd resolution, sandbox persistence/resume, cleanup,
command execution, resource conversion, interrupt handling, retry
exhaustion, and sandbox readiness checks. Integration tests verify
basic commands, filesystem ops, session persistence, and task
isolation against a live Daytona API.

Signed-off-by: rovle <lovre.pesut@gmail.com>

tests/integration/test_daytona_terminal.py

@@ -0,0 +1,123 @@
+"""Integration tests for the Daytona terminal backend.
+
+Requires DAYTONA_API_KEY to be set. Run with:
+    TERMINAL_ENV=daytona pytest tests/integration/test_daytona_terminal.py -v
+"""
+
+import json
+import os
+import sys
+from pathlib import Path
+
+import pytest
+
+pytestmark = pytest.mark.integration
+
+# Skip entire module if no API key
+if not os.getenv("DAYTONA_API_KEY"):
+    pytest.skip("DAYTONA_API_KEY not set", allow_module_level=True)
+
+# Import terminal_tool via importlib to avoid tools/__init__.py side effects
+import importlib.util
+
+parent_dir = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(parent_dir))
+
+spec = importlib.util.spec_from_file_location(
+    "terminal_tool", parent_dir / "tools" / "terminal_tool.py"
+)
+terminal_module = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(terminal_module)
+
+terminal_tool = terminal_module.terminal_tool
+cleanup_vm = terminal_module.cleanup_vm
+
+
+@pytest.fixture(autouse=True)
+def _force_daytona(monkeypatch):
+    monkeypatch.setenv("TERMINAL_ENV", "daytona")
+    monkeypatch.setenv("TERMINAL_CONTAINER_DISK", "10240")
+    monkeypatch.setenv("TERMINAL_CONTAINER_PERSISTENT", "false")
+
+
+@pytest.fixture()
+def task_id(request):
+    """Provide a unique task_id and clean up the sandbox after the test."""
+    tid = f"daytona_test_{request.node.name}"
+    yield tid
+    cleanup_vm(tid)
+
+
+def _run(command, task_id, **kwargs):
+    result = terminal_tool(command, task_id=task_id, **kwargs)
+    return json.loads(result)
+
+
+class TestDaytonaBasic:
+    def test_echo(self, task_id):
+        r = _run("echo 'Hello from Daytona!'", task_id)
+        assert r["exit_code"] == 0
+        assert "Hello from Daytona!" in r["output"]
+
+    def test_python_version(self, task_id):
+        r = _run("python3 --version", task_id)
+        assert r["exit_code"] == 0
+        assert "Python" in r["output"]
+
+    def test_nonzero_exit(self, task_id):
+        r = _run("exit 42", task_id)
+        assert r["exit_code"] == 42
+
+    def test_os_info(self, task_id):
+        r = _run("uname -a", task_id)
+        assert r["exit_code"] == 0
+        assert "Linux" in r["output"]
+
+
+class TestDaytonaFilesystem:
+    def test_write_and_read_file(self, task_id):
+        _run("echo 'test content' > /tmp/daytona_test.txt", task_id)
+        r = _run("cat /tmp/daytona_test.txt", task_id)
+        assert r["exit_code"] == 0
+        assert "test content" in r["output"]
+
+    def test_persistence_within_session(self, task_id):
+        _run("pip install cowsay 2>/dev/null", task_id, timeout=120)
+        r = _run('python3 -c "import cowsay; print(cowsay.__file__)"', task_id)
+        assert r["exit_code"] == 0
+        assert "cowsay" in r["output"]
+
+
+class TestDaytonaPersistence:
+    def test_filesystem_survives_stop_and_resume(self):
+        """Write a file, stop the sandbox, resume it, assert the file persists."""
+        task = "daytona_test_persist"
+        try:
+            # Enable persistence for this test
+            os.environ["TERMINAL_CONTAINER_PERSISTENT"] = "true"
+
+            # Write a marker file and stop the sandbox
+            _run("echo 'survive' > /tmp/persist_test.txt", task)
+            cleanup_vm(task)  # stops (not deletes) because persistent=true
+
+            # Resume with the same task_id — file should still exist
+            r = _run("cat /tmp/persist_test.txt", task)
+            assert r["exit_code"] == 0
+            assert "survive" in r["output"]
+        finally:
+            # Force-delete so the sandbox doesn't leak
+            os.environ["TERMINAL_CONTAINER_PERSISTENT"] = "false"
+            cleanup_vm(task)
+
+
+class TestDaytonaIsolation:
+    def test_different_tasks_isolated(self):
+        task_a = "daytona_test_iso_a"
+        task_b = "daytona_test_iso_b"
+        try:
+            _run("echo 'secret' > /tmp/isolated.txt", task_a)
+            r = _run("cat /tmp/isolated.txt 2>&1 || echo NOT_FOUND", task_b)
+            assert "secret" not in r["output"] or "NOT_FOUND" in r["output"]
+        finally:
+            cleanup_vm(task_a)
+            cleanup_vm(task_b)