ECS Architecture Compliance Check

Check the specified files or recent changes against project ECS rules.

this skill is called as

/check-ecs

Or with file name as arguments

/check-ecs file_name

MUST use ecs-architecture-checker agent to explore.

Target

If $ARGUMENTS is provided, check those files. Otherwise, check recently modified .rs files.

ECS Rules to Verify

1. Component Rules (ecs/component/)

• • Components are data-only structs — no impl blocks with logic
• • No fn methods that perform computation or mutation
• • Derive macros only (Debug, Clone, Default, etc.)
• • Located in src/ecs/component/

Violation example:

// BAD: Component with logic
impl MyComponent {
    pub fn calculate_something(&self) -> f32 { ... }
}

2. System Rules (ecs/systems/)

• • All behavior implemented as free functions
• • Function naming: <domain>_<action> (e.g., camera_rotate, animation_update)
• • Takes World/Components/Resources as parameters
• • Located in src/ecs/systems/

Violation example:

// BAD: Logic in component file
// src/ecs/component/camera.rs
impl Camera {
    pub fn rotate(&mut self, delta: Vector2) { ... }
}

// GOOD: Logic in system file
// src/ecs/systems/camera_systems.rs
pub fn camera_rotate(camera: &mut Camera, delta: Vector2) { ... }

3. Resource Rules (ecs/resource/)

• • Resources are global dynamic state that changes per frame
• • Static configuration should NOT be a resource
• • Located in src/ecs/resource/

4. mod.rs Rules

• • mod.rs files contain ONLY module declarations and re-exports
• • No struct/enum definitions in mod.rs
• • No function implementations in mod.rs

Violation example:

// BAD: Definition in mod.rs
// src/ecs/component/mod.rs
pub struct MyComponent { ... }

// GOOD: Only re-exports
// src/ecs/component/mod.rs
mod my_component;
pub use my_component::MyComponent;

5. Bones are NOT Entities

• • Bones are data within Skeleton.bones: Vec<Bone>
• • Bones identified by BoneId (u32 index), not Entity
• • Constraints reference bones via BoneId

6. EntityBuilder Pattern

• • Use existing EntityBuilder for entity construction
• • No manual component insertion sequences
• • Located in src/ecs/world.rs

Check Process

1. •Read the target files
2. •For each file, verify against applicable rules
3. •Report violations with file path and line number
4. •Suggest corrections

Output Format

## ECS Check Results

### ✅ Compliant
- file.rs: Components are data-only

### ❌ Violations
- src/ecs/component/foo.rs:45 - Component has logic method `calculate()`
  Suggestion: Move to `src/ecs/systems/foo_systems.rs`

- src/ecs/component/mod.rs:12 - Struct definition in mod.rs
  Suggestion: Move to separate file and re-export