core/cli: readline Tab completion and persistent history

Complete slash commands and provider/model/tools args; store history
under platformdirs user data.

tests/test_cli/test_readline_setup.py

@@ -0,0 +1,98 @@
+from __future__ import annotations
+
+import tomlkit
+
+from plyngent.cli.readline_setup import (
+    SLASH_COMMANDS,
+    build_completer,
+    filter_prefix,
+    history_path,
+)
+from plyngent.cli.state import ReplState
+from plyngent.config.models import ModelConfig, OpenAICompatibleProvider, OpenAIProvider
+from plyngent.config.store import ConfigStore
+
+
+def _minimal_state(tmp_path: object) -> ReplState:
+    from pathlib import Path
+    from unittest.mock import MagicMock
+
+    assert isinstance(tmp_path, Path)
+    provider = OpenAICompatibleProvider(
+        access_key_or_token="sk",
+        url="https://example.com/v1",
+        models={"alpha": ModelConfig(), "beta": ModelConfig()},
+    )
+    config = ConfigStore(path=tmp_path / "plyngent.toml", document=tomlkit.document())
+    config.providers = {
+        "local": OpenAIProvider(access_key_or_token="sk"),
+        "remote": provider,
+    }
+    # Avoid real client/network: build ReplState pieces manually via object.__new__
+    state = object.__new__(ReplState)
+    state.config = config
+    state.provider = provider
+    state.provider_name = "remote"
+    state.model = "alpha"
+    state.tools_enabled = True
+    state.memory = MagicMock()
+    state.workspace = tmp_path
+    state.session_id = None
+    state.client = MagicMock()
+    state.agent = MagicMock()
+    return state
+
+
+def test_filter_prefix() -> None:
+    assert filter_prefix("/he", ["/help", "/quit"]) == ["/help"]
+    assert filter_prefix("", ["a", "b"]) == ["a", "b"]
+
+
+def test_history_path_under_user_data() -> None:
+    path = history_path()
+    assert path.name == "repl_history"
+    assert "plyngent" in str(path)
+
+
+def test_completer_commands(tmp_path: object, monkeypatch: object) -> None:
+    import readline
+    from pathlib import Path
+
+    import pytest
+
+    assert isinstance(tmp_path, Path)
+    assert isinstance(monkeypatch, pytest.MonkeyPatch)
+
+    state = _minimal_state(tmp_path)
+    completer = build_completer(state)
+    monkeypatch.setattr(readline, "get_line_buffer", lambda: "/")
+    monkeypatch.setattr(readline, "get_begidx", lambda: 0)
+
+    found: list[str] = []
+    index = 0
+    while True:
+        item = completer("/", index)
+        if item is None:
+            break
+        found.append(item)
+        index += 1
+    assert "/help" in found
+    assert set(found) <= set(SLASH_COMMANDS)
+
+
+def test_completer_provider_args(tmp_path: object, monkeypatch: object) -> None:
+    import readline
+    from pathlib import Path
+
+    import pytest
+
+    assert isinstance(tmp_path, Path)
+    assert isinstance(monkeypatch, pytest.MonkeyPatch)
+
+    state = _minimal_state(tmp_path)
+    completer = build_completer(state)
+    monkeypatch.setattr(readline, "get_line_buffer", lambda: "/provider ")
+    monkeypatch.setattr(readline, "get_begidx", lambda: len("/provider "))
+
+    first = completer("r", 0)
+    assert first == "remote"