fix(chat): wire SystemPromptBuilder so persona files load in jarvis chat (fixes #458) (#497)

* fix(chat): wire SystemPromptBuilder so persona files load in jarvis chat (fixes #458)

* fix(chat): make `--persona none` actually disable persona files

This PR exposes `--persona none`, but SystemPromptBuilder._load_file read
empty paths as "." (Path("") -> ".") and raised IsADirectoryError, so the
documented opt-out crashed. Guard empty path_str so the "none" opt-out
(which _resolve_persona maps to empty file paths) cleanly injects no
persona. Adds an end-to-end regression test (building with persona
"none" must not raise). Also merges current main (branch was stale).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Jon Saad-Falcon <jonsaadfalcon@gmail.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/openjarvis/cli/chat_cmd.py

@@ -28,12 +28,22 @@ def _read_input(prompt: str = "You> ") -> Optional[str]:
 @click.option("-a", "--agent", "agent_name", default=None, help="Agent type.")
 @click.option("--tools", default=None, help="Comma-separated tool names.")
 @click.option("--system", "system_prompt", default=None, help="Custom system prompt.")
+@click.option(
+    "--persona",
+    "persona_name",
+    default=None,
+    help=(
+        "Named persona dir under ~/.openjarvis/personas/<name>/ "
+        "(overrides config). Pass 'none' to disable all persona files."
+    ),
+)
 def chat(
     engine_key: str | None,
     model_name: str | None,
     agent_name: str | None,
     tools: str | None,
     system_prompt: str | None,
+    persona_name: str | None,
 ) -> None:
     """Start an interactive multi-turn chat session.
 
@@ -48,6 +58,14 @@ def chat(
 
     config = load_config()
 
+    import dataclasses as _dc
+
+    effective_mf = (
+        _dc.replace(config.memory_files, persona_name=persona_name)
+        if persona_name is not None
+        else config.memory_files
+    )
+
     # Resolve engine
     from openjarvis.engine import get_engine
     from openjarvis.intelligence import register_builtin_models
@@ -121,6 +139,21 @@ def chat(
 
                     kwargs["interactive"] = True
                     kwargs["confirm_callback"] = _confirm
+
+                import inspect as _inspect
+
+                if (
+                    "prompt_builder"
+                    in _inspect.signature(agent_cls.__init__).parameters
+                ):
+                    from openjarvis.prompt.builder import SystemPromptBuilder
+
+                    kwargs["prompt_builder"] = SystemPromptBuilder(
+                        agent_template=config.agent.default_system_prompt or "",
+                        memory_files_config=effective_mf,
+                        system_prompt_config=config.system_prompt,
+                    )
+
                 agent = agent_cls(engine, model, **kwargs)
         except Exception as exc:
             console.print(f"[yellow]Agent '{agent_key}' failed: {exc}[/yellow]")
@@ -147,6 +180,16 @@ def chat(
     _notifications = NotificationDispatcher(get_status())
 
     # Conversation state
+    if not system_prompt:
+        from openjarvis.prompt.builder import SystemPromptBuilder
+
+        builder = SystemPromptBuilder(
+            agent_template=config.agent.default_system_prompt or "",
+            memory_files_config=effective_mf,
+            system_prompt_config=config.system_prompt,
+        )
+        system_prompt = builder.build()
+
     history: List[Message] = []
     if system_prompt:
         history.append(Message(role=Role.SYSTEM, content=system_prompt))

src/openjarvis/prompt/builder.py

@@ -229,6 +229,11 @@ class SystemPromptBuilder:
             )
 
     def _load_file(self, path_str: str, max_chars: int) -> str:
+        # An empty path means "no file" (e.g. the persona "none" opt-out, which
+        # resolves to empty paths). Guard before Path("") — which becomes "." —
+        # so reading it does not raise IsADirectoryError.
+        if not path_str:
+            return ""
         path = Path(path_str).expanduser()
         if not path.exists():
             return ""

tests/prompt/test_persona_scope.py

@@ -31,3 +31,23 @@ def test_named_persona_resolves_to_personas_dir():
 def test_path_traversal_rejected(bad):
     with pytest.raises(ValueError):
         SystemPromptBuilder._resolve_persona(MemoryFilesConfig(persona_name=bad))
+
+
+def test_none_persona_build_does_not_raise():
+    """Regression (#497): `--persona none` resolves to empty file paths; building
+    the prompt must not raise IsADirectoryError when those empty paths are read
+    (Path("") is "." — reading a directory raised before the empty-path guard).
+    """
+    import dataclasses
+
+    from openjarvis.core.config import load_config
+
+    cfg = load_config()
+    mf = dataclasses.replace(cfg.memory_files, persona_name="none")
+    builder = SystemPromptBuilder(
+        agent_template=cfg.agent.default_system_prompt or "",
+        memory_files_config=mf,
+        system_prompt_config=cfg.system_prompt,
+    )
+    out = builder.build()
+    assert isinstance(out, str)