Cannot read property 'forEach' of undefined when iterating html files

[skoblenick]

Linting all files with a global rule results in:

Linting "demo"...
Cannot read property 'forEach' of undefined
Occurred while linting ./apps/demo/src/app/app.component.html:1

I have a sample repo that reproduces the issue here: https://github.com/skoblenick/eslint-plugin-import-issue

I realize I could technically move the plugin into an override that is specific to the .ts files however it shouldn't be necessary when the code could just be more defensive. I could imagine a use case where I may have preprocessor working on imports within a html or template file (like an hbs) and I want them ordered (hence a lint check).

[ljharb]

It definitely should be necessary if you’re linting non-js files; typically those use an entirely separate config for reasons like this.

[skoblenick]

I have updated my repo and disabled the nx command caching.

The error seems to related to the rule import/first: error. If I disable this in the .eslintrc.yml the linter runs as expected (with lint errors due to the generated files).

[ljharb]

I'm not familiar with nx, and i don't see any linting-specific script in that repo's package.json.

npx eslint . fails, but since --ext has to be passed on the command line, i'm not sure how it's lining a .html file with that invocation. I do see the .html overrides section, but you'd need to disable a ton of rules in there since the primary purpose, default, and majority of rules are only for JS or similar code, not HTML.

What's happening is that you're getting very lucky - most rules don't use the Program visitor, and HTML files probably have AST node names that are completely distinct from JS ones. The import plugin has 15 rules using the Program visitor; you might just not have those enabled yet (the airbnb config enables most of them; i suggest using it).

The fix would be trivial - if (!body) { return; } - but i'd want a regression test for it. If you can make a PR that has a failing test case, I'd be happy to tack on the fix and get it in.

[skoblenick]

So I see a fix in a third party repo but I don't see this merged into main