Module API examples incorrect for Yarn Plug'n'Play

[MikeMcC399]

Subject

Guides > Module API

Description

https://docs.cypress.io/guides/guides/module-api

For Yarn Plug'n'Play the command node e2e-open-tests.js needs to be executed as:

yarn node e2e-open-tests.js

[elylucas]

@MikeMcC399 what is the suggestion here? It doesn't appear we are using yarn in any of the commands here

[MikeMcC399]

@elylucas

The command in the documentation node e2e-open-tests.js requires that Cypress has been installed. There are six different ways to do this (npm, pnpm, Yarn Classic, then Yarn Modern with its three different nodeLinker options: pnp, node-modules and pnpm) and all of them except Yarn Modern Plug'n'Play work by just specifying node. If you have however installed Cypress with Yarn Modern in Plug'n'Play mode you need to preface the call with yarn.

I was looking at this in conjunction with the introduction of Yarn Modern Plug'n'Play support in github-action and the absence of this information threw me to begin with until I got deeper into it. I didn't even know if Module API was compatible with Yarn Modern Plug'n'Play from reading the Module API documentation.

package \ command	node	yarn node
npm	y	y
pnpm	y	y
Yarn Classic	y	y
Yarn Modern pnp	x	y
Yarn Modern node-modules	y	y
Yarn Modern pnpm	y	y

The relevant bit of the Yarn Modern in Plug'n'Play mode documentation says:

For some remaining edge cases, a small setup may be required:

If you need to run an arbitrary Node script, use yarn node as the interpreter, instead of node. This will be enough to register the .pnp.cjs file as a runtime dependency.

[MikeMcC399]

So the suggestion would be to add a comment to preface the command with yarn when Yarn Plug'n'Play is being used, with a reference to Yarn's documentation page https://yarnpkg.com/features/pnp,

[elylucas]

Sorry, not too familiar with yarn pnp. Is this something that a yarn person would just know they have to do if they are using pnp? Would this change entail updating all the shell examples to have a yarn pnp usage as well, or a note to yarn pnp users somewhere?

[MikeMcC399]

I'll make a concrete proposal in a PR for minimal changes to the docs. I think just a note would be sufficient without updating every single example.

[MikeMcC399]

Sorry, not too familiar with yarn pnp.

That makes two of us!

Is this something that a yarn person would just know they have to do if they are using pnp?

I can't really answer that as I wouldn't consider myself to be a "yarn person". It's probably better not to assume too much prior knowledge.

In any case I've now submitted a suggestion as PR #5254 for you to take a look at. There are currently several issues in Cypress with Yarn Plug'n'Play so I had to go back to [email protected] to demonstrate it. I've tried to keep the text short and simple.