Tests for HermesContext and HermesCache

src/hermes/model/context_manager.py

@@ -55,10 +55,18 @@ def prepare_step(self, step: str, *depends: str) -> None:
         self._current_step.append(step)
 
     def finalize_step(self, step: str) -> None:
-        current_step = self._current_step.pop()
-        if current_step != step:
-            raise ValueError("Cannot end step %s while in %s.", step, self._current_step[-1])
+        if len(self._current_step) < 1:
+            raise ValueError("There is no step to end.")
+        if self._current_step[-1] != step:
+            raise ValueError(f"Cannot end step {step} while in {self._current_step[-1]}.")
+        self._current_step.pop()
 
     def __getitem__(self, source_name: str) -> HermesCache:
+        if len(self._current_step) < 1:
+            raise HermesContexError("Prepare a step first.")
         subdir = self.cache_dir / self._current_step[-1] / source_name
         return HermesCache(subdir)
+
+
+class HermesContexError(Exception):
+    pass

test/__init__.py

@@ -0,0 +1,3 @@
+# SPDX-FileCopyrightText: 2025 German Aerospace Center (DLR)
+#
+# SPDX-License-Identifier: Apache-2.0

test/hermes_test/__init__.py

@@ -1,3 +1,3 @@
-# SPDX-FileCopyrightText: 2022 German Aerospace Center (DLR)
+# SPDX-FileCopyrightText: 2025 German Aerospace Center (DLR)
 #
 # SPDX-License-Identifier: Apache-2.0

test/hermes_test/model/test_context_manager.py

@@ -0,0 +1,87 @@
+# SPDX-FileCopyrightText: 2025 German Aerospace Center (DLR)
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# SPDX-FileContributor: Michael Meinel
+# SPDX-FileContributor: Sophie Kernchen
+import pytest
+from pathlib import Path
+
+from hermes.model.context_manager import HermesContext, HermesCache, HermesContexError
+
+
+def test_context_hermes_dir_default():
+    ctx = HermesContext()
+    assert ctx.cache_dir == Path('./.hermes').absolute()
+
+
+def test_context_hermes_dir_custom():
+    ctx = HermesContext(Path('spam'))
+    assert ctx.cache_dir == Path('spam') / '.hermes'
+
+
+def test_get_context_default():
+    ctx = HermesContext()
+    ctx.prepare_step("ham")
+    assert ctx["spam"]._cache_dir == Path('./.hermes/ham/spam').absolute()
+
+
+def test_context_get_error():
+    ctx = HermesContext()
+    ctx.prepare_step("ham")
+    ctx.finalize_step("ham")
+    with pytest.raises(HermesContexError, match="Prepare a step first."):
+        ctx["spam"]._cache_dir == Path('./.hermes/spam').absolute()
+
+
+def test_finalize_context_one_item():
+    ctx = HermesContext()
+    ctx.prepare_step("ham")
+    ctx.finalize_step("ham")
+    assert ctx._current_step == []
+
+
+def test_finalize_context():
+    ctx = HermesContext()
+    ctx.prepare_step("ham")
+    ctx.prepare_step("spam")
+    ctx.finalize_step("spam")
+    assert ctx["spam"]._cache_dir == Path('./.hermes/ham/spam').absolute()
+    assert ctx._current_step == ["ham"]
+
+
+def test_finalize_context_error_no_item():
+    ctx = HermesContext()
+    with pytest.raises(ValueError, match="There is no step to end."):
+        ctx.finalize_step("spam")
+
+
+def test_finalize_context_error():
+    ctx = HermesContext()
+    ctx.prepare_step("ham")
+    with pytest.raises(ValueError, match="Cannot end step spam while in ham."):
+        ctx.finalize_step("spam")
+
+
+def test_cache(tmpdir):
+    ctx = HermesContext(Path(tmpdir))
+    ctx.prepare_step("ham")
+    with ctx["spam"] as c:
+        c["bacon"] = {"data": "goose", "num": 2}
+
+    path = tmpdir / Path('.hermes') / 'ham' / 'spam' / 'bacon.json'
+    assert path.exists()
+    assert path.read() == '{"data": "goose", "num": 2}'
+    assert c._cached_data["bacon"] == {"data": "goose", "num": 2}
+
+
+def test_hermes_cache_set(tmpdir):
+    cache = HermesCache(Path(tmpdir))
+    cache["bacon"] = "eggs"
+    assert cache._cached_data == {"bacon": "eggs"}
+
+
+def test_hermes_cache_get(tmpdir):
+    cache = HermesCache(Path(tmpdir))
+    cache._cached_data = {"bacon": "eggs"}
+    assert cache["bacon"] == "eggs"