migrate-to-shoehorn
Migrate test files from `as` type assertions to @total-typescript/shoehorn. Use when user mentions shoehorn, wants to replace `as` in tests, or needs partial test data.
- Kind
- Skill
- Works with
- Claude Code
- Languages
- TypeScript / JavaScript
- Source
- mattpocock/skills @ 24fe0ef7737e
- Path
- skills/misc/migrate-to-shoehorn/SKILL.md
- License
- MIT
- Jobs
- Testing
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# 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
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