id: rust-todo-unimplemented
name: Unfinished Stub Macro
severity: warning
category: correctness
defect_class: correctness
inline_tier: blocking
language: rust

message: "todo!() / unimplemented!() stub — function was scaffolded but never completed"

description: |
  todo!() and unimplemented!() always panic at runtime. They are scaffolding
  markers that must be replaced before shipping.

  ✅ FIX: implement the function body or return an appropriate error.

query: |
  (macro_invocation
    macro: (identifier) @MACRO
    (#match? @MACRO "^(todo|unimplemented)$")) @CALL

metavars:
  - MACRO
  - CALL

has_fix: false

tags:
  - rust
  - correctness
  - stub
  - panic

examples:
  bad: |
    fn process_payment(amount: f64) -> Result<Receipt> {
        todo!()
    }

    fn legacy_path() -> bool {
        unimplemented!()
    }

  good: |
    fn process_payment(amount: f64) -> Result<Receipt> {
        stripe_client.charge(amount).map(Receipt::from)
    }