Remove circular imports in typescript code, add linting

[davidjgoss]

Details

Remove circular imports in messages TypeScript code and add eslint-plugin-import to lint against future regressions.

Motivation and Context

See #1279 which this helps with but doesn't close, because we have a similar issue in the protobufjs library.

These issues block us upgrading to webpack 5 in the HTML formatter. Node's module resolution handles them okay and apparently so does webpack 4, but the runtime module resolution seems to have changed somehow with 5.

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 not work as expected).

Checklist:

• The change has been ported to Java.
• The change has been ported to Ruby.
• The change has been ported to JavaScript.
• The change has been ported to Go.
• The change has been ported to .NET.
• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have updated the CHANGELOG accordingly.

[davidjgoss]

@aslakhellesoy thanks for moving this forward, I hadn't caught on that it would fail unless all eslint configs were the same (this should get easier if we can make npm workspaces happen). I see there are some failures on this rule in gherkin and cucumber-expressions, shall I pick this back up and work on those? (It's not super urgent to fix this, just prevents upgrading to webpack 5.)

[aslakhellesoy]

Hi @davidjgoss yes, that would be great if you could continue the untangling of the circular deps in gherkin and cucumber-expressions.

Thanks!!

[aslakhellesoy]

Allright, that's cucumber-expressions done. I'll have a quick go at gherkin too....

[aslakhellesoy]

Gherkin circular dependency:

[aslakhellesoy]

I think Gherkin circulars are gone now - still some small things to fix in cucumber-expressions it seems...

[aslakhellesoy]

You opened a can of worms here @davidjgoss :-)

But I'm glad you did. Keeping code nicely decoupled is something I care deeply about, and this has been an eye opener for me. It's the first time (I think) that I have worked with a system that disallows circular dependencies at the compilation level.

I've not seen it in Java or C# before, or any other language (although I'm sure it exists).

In order to untangle these circular dependencies I was forced to do what I have considered good practice for 15 years - interface-implementation separation. But I don't always practice what I preach, so having a tool that enforces this is great!

I'll be using this on all my TypeScript code from now on I think.

@mpkorstanje is there anything similar in Java that you know of?

[davidjgoss]

@aslakhellesoy awesome, thanks for getting it over the line (i.e. the last, er, 99%)