isStaticExport logic fails if the build command doesn't contain "next export"

[alexshyba]

This is borderlining between a bug and feature request :)

Describe the bug
We had the plugin start failing recently. What ended up happening is that the isStaticExport wasn't detected anymore.

const isStaticExport = usesBuildCommand({ build, scripts, command: "next export" })

To Reproduce
Steps to reproduce the behavior:

1. Add "build: next build" and "export: next export" to your package.json.
2. Specify this as your Netlify build command as "netlify:build": "npm run build && npm run export"
3. Run build and notice that the static export wasn't detected.

This is due to "next export" not found in the build command string.

Expected behavior

This could be a fragile way of detecting whether the plugin should run or not. Since there doesn't seem to be a way to opt out of the plugin install, I think it's worth reviewing the approach here.

Option 1: Provide more flexibility to detect the static build
Option 2: Provide a way to opt out of having the plugin to auto-install at all (I think many will prefer having this option in an env var or something)

Versions

• Next.js: 11.0.1
• plugin (if installed at fixed version): 3.6.3

[ascorbic]

Well found! That's a really good point: we need a more robust way of detecting which scripts are run. I'll look at that today. The addition of an env var to disable all plugin auto install is a really good idea too. I'll raise that with the team.

[alexshyba]

hi @ascorbic, looks like the issue is back for us in 4.0.0, breaking all our sites :)
We are using SSG mode and a custom npm run export script:

[build]
  command = 'npm run export'
  publish = 'out'

package.json:

 "export": "next build && next export",

The problem is that the next.js plugin is auto-installed and breaks the build with this:

4:35:37 PM: ────────────────────────────────────────────────────────────────
4:35:37 PM:   4. @netlify/plugin-nextjs (onBuild event)                     
4:35:37 PM: ────────────────────────────────────────────────────────────────
4:35:37 PM: ​
4:35:38 PM: ​
4:35:38 PM: ────────────────────────────────────────────────────────────────
4:35:38 PM:   Plugin "@netlify/plugin-nextjs" failed                        
4:35:38 PM: ────────────────────────────────────────────────────────────────
4:35:38 PM: ​
4:35:38 PM:   Error message
4:35:38 PM:   Error: The directory "out" does not contain a Next.js production build. Perhaps the build command was not run, or you specified the wrong publish directory.
4:35:38 PM:   Your publish directory is set to "out", but in most cases it should be ".next".
4:35:38 PM:   If you are using "next export" then the Essential Next.js plugin should be removed. See https://ntl.fyi/remove-plugin for details.

Is there a way to make sure that the plugin doesn't auto-install?

[ascorbic]

Good point. There isn't a way to disable auto-install, but I could add an env var to disable everything except caching. Would that work for you?

[alexshyba]

@ascorbic that would be amazing, thanks, Matt!
as a workaround, I had to pin the version of the plugin to v3, which is not a good long term solution :)