refactor typedefs for cy

[kuceb]

for users/plugin-authors who just want to extend cy and not the Cypress.Chainable

for example, I want to do this:

namespace Cypress {
  interface cy {
    retries: Mocha.ISuiteCallbackContext.retries
  }
}

to indicate I can only access my property on the parent cy

tasks

• add dtslint test
• closes Provide example how one can add custom commands and properties to cy object #4715

[bahmutov]

@bkucera can you add a dtslint test if possible for this? That checks that someone can actually extend cy object without extending Chainable interface?

[bahmutov]

can this interface cy be documented please?

[bahmutov]

this needs more documentation - this is what someone who writes a new command or adds a property to cy global object should do right. So we should describe this better, even for ourselves.

Also, the formatting is all off below, maybe it needs a prettier ...

[bahmutov]

@bkucera I love the refactoring and the type test, and this seems like the simplest way to extend Cypress with a custom command, but I would love to see more JSDoc comments before merging it

[bahmutov]

is this the right command now? to lint?

[bahmutov]

I have removed a few @example in JSDoc because seems VSCode has changed how it shows intellisense popups, and the examples really looked bad

with @example

without @example

[bahmutov]

looks good

[bahmutov]

I have tried this change against cypress-example-todomvc custom commands, seems still to pass just fine