Add test_stash_exp.

tests/func/experiments/test_stash_exp.py

@@ -0,0 +1,68 @@
+import logging
+
+import pytest
+from funcy import first
+
+
+@pytest.mark.xfail(reason="TODO: https://github.com/iterative/dvc/issues/6297")
+@pytest.mark.parametrize("tmp", [True, False])
+@pytest.mark.parametrize("staged", [True, False])
+def test_deleted(tmp_dir, scm, dvc, caplog, tmp, staged):
+    tmp_dir.scm_gen("file", "file", commit="commit file")
+    stage = dvc.stage.add(
+        cmd="cat file",
+        name="foo",
+    )
+    scm.add_commit(["dvc.yaml"], message="add dvc.yaml")
+
+    file = tmp_dir / "file"
+    file.unlink()
+    if staged:
+        scm.add(["file"])
+
+    with caplog.at_level(logging.ERROR):
+        results = dvc.experiments.run(stage.addressing, tmp_dir=tmp)
+        assert "Failed to reproduce experiment" in caplog.text
+        assert not results
+
+    assert not file.exists()
+
+
+@pytest.mark.parametrize("tmp", [True, False])
+@pytest.mark.parametrize("staged", [True, False])
+def test_modified(tmp_dir, scm, dvc, caplog, tmp, staged):
+    tmp_dir.scm_gen("file", "file", commit="commit file")
+    stage = dvc.stage.add(
+        cmd="cat file",
+        name="foo",
+    )
+    scm.add_commit(["dvc.yaml"], message="add dvc.yaml")
+
+    (tmp_dir / "file").write_text("modified_file")
+    if staged:
+        scm.add(["file"])
+
+    results = dvc.experiments.run(stage.addressing, tmp_dir=tmp)
+
+    exp = first(results)
+    scm.checkout(exp, force=True)
+    assert (tmp_dir / "file").read_text() == "modified_file"
+
+
+@pytest.mark.parametrize("tmp", [True, False])
+def test_staged_new_file(tmp_dir, scm, dvc, tmp):
+    if not tmp:
+        pytest.xfail("TODO: https://github.com/iterative/dvc/issues/8998")
+    stage = dvc.stage.add(
+        cmd="cat file",
+        name="foo",
+    )
+    scm.add_commit(["dvc.yaml"], message="add dvc.yaml")
+
+    (tmp_dir / "file").write_text("file")
+    scm.add(["file"])
+
+    results = dvc.experiments.run(stage.addressing, tmp_dir=tmp)
+    exp = first(results)
+    fs = scm.get_fs(exp)
+    assert fs.exists("file")