add eslint-import rule no-cycle

[Connum]

Description

Added the eslint-import plugin and activated the no-cycle rule, so we'll catch any accidental circular dependencies.

Motivation and Context

I saw the comment in glyph.js regarding the circumvention of a possible circular dependency with tables/glyf.js and wanted to make sure we catch similar situations in the future.

How Has This Been Tested?

npm run lint

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I did npm run test and all tests passed green (including code styling checks).
• I have added tests to cover my changes.
• My change requires a change to the documentation.
• I have updated the README accordingly.
• I have read the CONTRIBUTING document.

[ILOVEPIE]

This looks good to me.

[yne]

isn't it already supposed to be detected at ci level (when building or running the tests ?)

[Connum]

I think I tested it by producing a circular dependency in the glyf file and esbuild didn't complain about it iirc. But it's still an antipattern.

[yne]

I added a import {parse} from './opentype.mjs'; in font.mjs (and added a fake if(parse)parse; in a font function)

but npm run lint did not reported it.

Did I missunderstood it usage ? Or did it simply never worked ?

[Connum]

It must have worked at one point, or I wouldn't have made the PR :) But maybe some changes lead to it not working anymore, as we don't have any tests for the linting