Fix #8: Generated type of expect

[FTWinston]

Declaring the type explicitly seems to fix the generated type definitions.

With this change, index.d.ts generates as:

import { default as expectPatched } from '@storybook/expect';
import * as mock from 'jest-mock';
export declare const jest: typeof mock;
export declare const expect: typeof expectPatched;

instead of as

import * as mock from 'jest-mock';
export declare const jest: typeof mock;
export declare const expect: import("expect/build/types").Expect<import("expect/build/types").MatcherState>;

This prevents the typescript-eslint errors reported on #8.

[yannbf]

Hey @FTWinston thanks a lot for your contribution! I think this is great but still there is a problem with the package, which is the fact that @storybook/expect, although it include types, it actually just re-exports types from expect, but it does not have it as a peerDependency. People who don't have expect in their projects at all will still have typing issues. But anyways, this PR already provides a great fix for those who do have expect!

[FTWinston]

Hmm, so should @storybook/jest list expect as a peer dependency (too), or should that be left to @storybook/expect?

[yannbf]

Hmm, so should @storybook/jest list expect as a peer dependency (too), or should that be left to @storybook/expect?

Great question! Expect is bundled in @storybook/expect, but the types are lost. We need to figure out a way to copy and re-export the types from that package so there's no need to install expect only for the types!

[github-actions]

🚀 PR was released in v0.0.6 🚀