Typescript Definition for 'createAppTester' has a bug

[boedlen]

In https://github.com/zapier/zapier-platform-cli/issues/15 I proposed a change to the createAppTester type, to allow for better type safety in tests. The change worked great I think, but I've just notice that it doesn't play nicely with Bundle<ISomeInterface>.

The problem is that if you have supplied your own InputData type like this:

{
  list: {
    operation: {
      perform: async (z: zObject, bundle: Bundle<PopupSubmissionInputData>) => {},
      sample: {}
    }
  }
}

The compiler will throw an error like this, when using the appTester with appTester(xxxx.list.operation.perform, bundle)

What would you like to change?

To fix this problem, I propose yet another fix to the type:

export const createAppTester: (
  appRaw: object
) => <T extends any>(
  func: (z: zObject, bundle: Bundle) => Promise<T>,
  bundle?: Partial<Bundle> // partial so we don't have to make a full bundle in tests
) => T extends Promise<T> ? T : Promise<T>;

Where we change to type of bundle to be anything that extends Bundle. (Much like we did with the return type of func)

Here's what I think the type should look like:

export const createAppTester: (
  appRaw: object
) => <T extends any, B extends Bundle>(
  func: (z: zObject, bundle: B) => Promise<T>,
  bundle?: Partial<B> // partial so we don't have to make a full bundle in tests
) => T extends Promise<T> ? T : Promise<T>;

The new definition supports both Bundle and Bundle<ISomeInterface>

Your Environment

• CLI Version 7.0.0
• Windows 10

[xavdid]

Cool! This level of detail is a little out of my typescript depth, but it seems like a reasonable change. I'll get a PR out for this and some other TS related fixes.