---
id: TASK-1.2
title: 'Add unit tests for config module (load, schema)'
status: Done
assignee:
  - codex
created_date: '2026-02-23 12:50'
updated_date: '2026-02-23 12:54'
labels:
  - tests
dependencies: []
references:
  - src/config/schema.rs
  - src/config/load.rs
parent_task_id: TASK-1
---

## Description

<!-- SECTION:DESCRIPTION:BEGIN -->
Create focused unit tests for config module behaviors: TOML parsing, error cases, overlay precedence, and arg list flattening.
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## Acceptance Criteria
<!-- AC:BEGIN -->
- [x] #1 Schema overlay behaviors are covered (FileConfig, ProjectCfg, ZephyrCfg, BuildCfg, ProfileCfg, PhaseArgsCfg).
- [x] #2 ArgList/ArgAtom parsing and flattening behaviors are covered for single and list forms.
- [x] #3 load_config covers success path and error paths (missing file, invalid TOML) using temp directories.
- [x] #4 Tests run without requiring external resources.
<!-- AC:END -->

## Implementation Plan

<!-- SECTION:PLAN:BEGIN -->
1) Review `src/config/schema.rs` and `src/config/load.rs` to identify key behaviors to test.
2) Add unit tests in module-local `#[cfg(test)]` sections covering overlay precedence, ArgList/ArgAtom parsing + flattening, and load_config success/error paths using temp dirs.
3) Run `just test` to verify.
<!-- SECTION:PLAN:END -->

## Implementation Notes

<!-- SECTION:NOTES:BEGIN -->
Plan approved by user on 2026-02-23.

Added unit tests in `src/config/schema.rs` for overlay behaviors and ArgList flattening/deserialization.

Added unit tests in `src/config/load.rs` for load_config success and error paths using temp dirs.

Ran `just test` (nextest) successfully.
<!-- SECTION:NOTES:END -->
