loki/docs/testing/plans/01-config-and-appconfig.md

Test Plan: Config Loading and AppConfig

Feature description

Loki loads its configuration from a YAML file (config.yaml) into a Config struct, then converts it to AppConfig (immutable, shared) + RequestContext (mutable, per-request). The AppConfig holds all serialized fields; RequestContext holds runtime state.

Behaviors to test

Config loading

• Config loads from YAML file with all supported fields
• Missing optional fields get correct defaults (config_defaults_match_expected)
• model_id defaults to first available model if empty (requires Config::init, integration test)
• temperature, top_p default to None
• stream defaults to true
• save defaults to false (CORRECTED: was listed as true)
• highlight defaults to true
• dry_run defaults to false
• function_calling_support defaults to true
• mcp_server_support defaults to true
• compression_threshold defaults to 4000
• document_loaders populated from config and defaults (requires Config::init)
• clients parsed from config (to_app_config_copies_clients)

AppConfig conversion

• to_app_config() copies all serialized fields correctly
• clients field populated on AppConfig
• visible_tools correctly computed from enabled_tools config (deferred to plan 16)
• mapping_tools correctly parsed
• mapping_mcp_servers correctly parsed
• user_agent resolved (auto → crate name/version)

RequestContext conversion

• to_request_context() copies all runtime fields (to_request_context_creates_clean_state)
• model field populated with resolved model (requires Model::retrieve_model)
• working_mode set correctly (Repl vs Cmd)
• tool_scope starts with default (empty)
• agent_runtime starts as None

AppConfig field accessors

• editor() returns configured editor or $EDITOR
• light_theme() returns theme flag
• render_options() returns options for markdown rendering
• sync_models_url() returns configured or default URL

Dynamic config updates

• update_app_config closure correctly clones and replaces Arc
• Changes to dry_run, stream, save persist across calls
• Changes visible to subsequent ctx.app.config reads

Context switching scenarios

• AppConfig remains immutable after construction (no field mutation)
• Multiple RequestContexts can share the same AppState
• Changing AppConfig fields (via clone-mutate-replace) doesn't affect other references to the old Arc

Old code reference

• src/config/mod.rs — Config struct, Config::init, defaults
• src/config/bridge.rs — to_app_config, to_request_context
• src/config/app_config.rs — AppConfig struct and methods