# Replace an imperative pattern with the project idiom

Code written before the current idiom, moved onto it module by module with a rule to hold the line.

Category: Refactors and cleanup
Source: https://letsship.ai/use-cases/replace-an-imperative-pattern
Published: 2026-08-25

## Goal

Rewrite one module onto the project's current idiom without changing behaviour.

## Acceptance criteria

- The module follows the current idiom throughout
- Behaviour is unchanged, proven by the existing tests
- A rule enforces the idiom for new code
- The remaining modules are counted

## What lands as proof

An unchanged test suite passing, plus a rule that stops the old pattern reappearing.

## Prompt

Copy this to an agent to open the ticket:

```text
Create a Linear issue in my team and assign it to the SHIP agent.

Title: Move {module} onto the {idiom} idiom

Description: Rewrite one module onto the project's current idiom without changing behaviour.

Acceptance criteria:
- The module follows the current idiom throughout
- Behaviour is unchanged, proven by the existing tests
- A rule enforces the idiom for new code
- The remaining modules are counted

Before you create the issue, identify an idiom this repository has adopted unevenly and replace {idiom} and {module}.
```

## Questions

### What does the agent actually change?

The ticket is scoped to one outcome: rewrite one module onto the project's current idiom without changing behaviour. Work that serves that outcome is in scope, and anything outside it is left for a separate ticket, so the pull request stays reviewable.

### How do I know the work is done?

The pull request carries the evidence, not only the diff. Here that means behaviour unchanged, tests green, the idiom enforced by a rule, so a reviewer can confirm the result without reproducing the work locally.

### How much oversight does this need?

None is required before the run starts. Every claim this ticket makes can be checked by machine, so the agent works straight through and a person reviews the finished pull request like any other.