[Feature] Update the readme with instructions on how to add the attachFile command to typescript intellisense

[UncleGus]

Current behavior:

When using the .attachFile() command, intellisense doesn't recognise it and underlines it red.

Desired behavior:

Intellisense should recognise the command. This can be achieved by adding the command to index.d.ts in the cypress/support folder. More details in the Cypess custom commands documentation.

Versions

N/A

[MCFreddie777]

Would help a lot.

[abramenal]

Hi @UncleGus @MCFreddie777 did you have a chance to check #167

index.d.ts is currently defined, but for some reason multiple users experience this issue. I'm not sure how exactly it should be fixed

[peterkrieg]

@abramenal I just posted (#167 (comment)) in that issue (which I think can be closed if the solution works for people).

I'd be happy to make a small PR outlining how to add the types to the tsconfig.json. I'm thinking it could be a small blurb similar to how cypress-testing-library does it here: https://github.com/testing-library/cypress-testing-library#with-typescript

Let me know what you think!

[abramenal]

Hi @peterkrieg
Thanks for this solution! While waiting for someone else's feedback we can work on the PR.
Example that you mentioned is perfect – we can copy both With TypeScript and Intellisense for JavaScript with VS Code sections and put it between Installation and Usage too 👍

[MCFreddie777]

Update:
I tried multiple solutions but only one worked.

Previously I used typeRoots in my project, so I tried to add it there:

// /cypress/tsconfig.json
  "typeRoots": [
            "../node_modules/@types",
            "../node_modules/cypress/types",
            "../types",
            "../node_modules/cypress-file-upload"
        ]

Using this solution, my IDE (WebStorm) stopped complaining about not existing property, but when I ran the tests, I started getting errors such as Cannot find type definition file for 'dist' or 'node_modules'.

Maybe its worth to mention that I'm running cypress@4.12.1 but without out-of-the-box typescript, still using @cypress/webpack-preprocessor to transpile typescript into js.

Well, I started trying more solutions as adding "../node_modules/cypress-file-upload/types" into the typeRoots, not working.
Tried adding /// <reference types="Cypress" /> to the beginning of file where I am using the attachFile function with no luck.

The only solution that worked is:

// /cypress/tsconfig.json
  "types": ["cypress", "cypress-file-upload"],
   "typeRoots": [
         "../node_modules/@types",
         "../types"
   ]

You can use both typeRoots and types in your cypress/tsconfig.json file.

[andrico1234]

The only solution that worked is:

// /cypress/tsconfig.json
"types": ["cypress", "cypress-file-upload"],
"typeRoots": [
"../node_modules/@types",
"../types"
]
You can use both typeRoots and types in your cypress/tsconfig.json file.

This worked for me straight away, I'm surprised that this is not documented in the README.

[abramenal]

I think README indeed lacks of clarity on using command with TS, might be a good improvement for upcoming v5 release.
In the meantime, if someone has courage to do it now, would really appreciate it!

[andrico1234]

I whipped up a super quick MR to include @MCFreddie777 's .tsconfig changes to the README, you can find it here: #246