migrate-to-shoehornlisted
Install: claude install-skill 20231118185SSPU/prompt-optimizer
# Migrate to Shoehorn
## Why shoehorn?
`shoehorn` lets you pass partial data in tests while keeping TypeScript happy. It replaces `as` assertions with type-safe alternatives.
**Test code only.** Never use shoehorn in production code.
Problems with `as` in tests:
- Trained not to use it
- Must manually specify target type
- Double-as (`as unknown as Type`) for intentionally wrong data
## Install
```bash
npm i @total-typescript/shoehorn
```
## Migration patterns
### Large objects with few needed properties
Before:
```ts
type Request = {
body: { id: string };
headers: Record<string, string>;
cookies: Record<string, string>;
// ...20 more properties
};
it("gets user by id", () => {
// Only care about body.id but must fake entire Request
getUser({
body: { id: "123" },
headers: {},
cookies: {},
// ...fake all 20 properties
});
});
```
After:
```ts
import { fromPartial } from "@total-typescript/shoehorn";
it("gets user by id", () => {
getUser(
fromPartial({
body: { id: "123" },
}),
);
});
```
### `as Type` → `fromPartial()`
Before:
```ts
getUser({ body: { id: "123" } } as Request);
```
After:
```ts
import { fromPartial } from "@total-typescript/shoehorn";
getUser(fromPartial({ body: { id: "123" } }));
```
### `as unknown as Type` → `fromAny()`
Before:
```ts
getUser({ body: { id: 123 } } as unknown as Request); // wrong type on purpose
```
After:
```ts
import { fromAny } from "@total-typescript/shoehorn";
getU