Continue GC code review: Pydantic

tests/test_prompts.py

@@ -1,7 +1,17 @@
 """Tests for prompt artifacts in prompts/."""
 
+import hashlib
 from pathlib import Path
 
+import pytest
+from pydantic import ValidationError
+
+from transcription.config import Settings
+from transcription.services.sources import PromptExecution
+from transcription.services.sources import PromptLoadError
+from transcription.services.sources import build_prompt_execution
+from transcription.services.sources import load_prompt_text
+
 PROMPT_PATH = Path("prompts/transcribe_document.md")
 
 
@@ -39,3 +49,45 @@ class TestPromptArtifact:
         text = _prompt_text().lower()
         assert "[deleted:" in text
         assert "[inserted:" in text
+
+
+class TestPromptConfiguration:
+    def test_builds_validated_immutable_prompt_provenance(self, tmp_path):
+        prompt_text = "Transcribe this document verbatim."
+        (tmp_path / "custom.md").write_text(prompt_text, encoding="utf-8")
+        settings = Settings(
+            openrouter_api_key="test-key",
+            prompt_dir=tmp_path,
+            default_prompt_name="custom.md",
+            transcription_temperature=0.2,
+            transcription_top_p=0.9,
+        )
+
+        execution = build_prompt_execution(settings=settings)
+
+        assert execution.prompt_hash == hashlib.sha256(prompt_text.encode()).hexdigest()
+        assert execution.temperature == 0.2
+        assert execution.top_p == 0.9
+        with pytest.raises(ValidationError):
+            execution.prompt_name = "changed.md"
+
+    def test_rejects_prompt_path_traversal_even_with_direct_loader_call(self, tmp_path):
+        outside_prompt = tmp_path / "outside.md"
+        prompt_dir = tmp_path / "prompts"
+        prompt_dir.mkdir()
+        outside_prompt.write_text("secret", encoding="utf-8")
+        settings = Settings(openrouter_api_key="test-key", prompt_dir=prompt_dir)
+
+        with pytest.raises(PromptLoadError):
+            load_prompt_text(prompt_name="../outside.md", settings=settings)
+
+    def test_prompt_execution_rejects_invalid_provenance_hash(self):
+        with pytest.raises(ValidationError):
+            PromptExecution(
+                prompt_name="prompt.md",
+                prompt_hash="not-a-sha256",
+                system_prompt=None,
+                user_prompt="text",
+                temperature=None,
+                top_p=None,
+            )