Add test cases for fs operations

Author: MaddyGuthridge

pyproject.toml

@@ -56,6 +56,7 @@ dev = [
     "coverage>=7.9.1,<8",
     "jestspectation>=1.4.5,<2",
     "types-aiofiles>=24.1.0.20250708,<26",
+    "pytest-asyncio>=1.2.0",
 ]
 
 [build-system]

tests/actions/fs_test.py

@@ -0,0 +1,41 @@
+"""
+tests / actions / fs_test.py
+
+Test cases for file system operations
+"""
+
+import pytest
+
+from markten import ActionSession
+from markten.actions import fs
+
+
+@pytest.mark.asyncio
+async def test_read_write_file():
+    action = ActionSession("test")
+    dir = await fs.temp_dir(action)
+
+    await fs.write_file(action, dir / "file", "Some text")
+
+    assert await fs.read_file(action, dir / "file") == "Some text"
+
+
+@pytest.mark.asyncio
+async def test_cannot_overwrite_file():
+    action = ActionSession("test")
+    dir = await fs.temp_dir(action)
+
+    await fs.write_file(action, dir / "file", "Some text")
+
+    with pytest.raises(FileExistsError):
+        await fs.write_file(action, dir / "file", "Some text")
+
+
+@pytest.mark.asyncio
+async def test_force_overwrite_file():
+    action = ActionSession("test")
+    dir = await fs.temp_dir(action)
+
+    await fs.write_file(action, dir / "file", "Some text")
+
+    await fs.write_file(action, dir / "file", "Some text", overwrite=True)