Any reason for adding the no-unused-variable rule?

Without no-unused-variable, the following lint warnings happen. There are no tests to validate that these can be removed so the best assumption is that they belong and the lint errors should be ignored.

web-tmpnb:

ipywidgets/examples/web-tmpnb/src/index.ts
ERROR: 46:21  no-unused-variable  'editor' is declared but never used.
ERROR: 57:21  no-unused-variable  'manager' is declared but never used.

web3:

ipywidgets/examples/web3/src/index.ts
ERROR: 33:13  no-unused-variable  'editor' is declared but never used.

ipywidgets/examples/web3/src/manager.ts
ERROR: 18:5   no-unused-variable  'requirePromise' is declared but never used.

The web-tmpnb example is currently broken (noted in the example README) - that's why it's only half-written right now.

For both examples, the editor variable doesn't need to be stored - we could just call the CodeMirror function.

We can delete the requirePromise function in web3. It now uses the HTMLManager, and should import those functions from the lib-embed.ts defined in the html manager package.

And for now, we can just not store the manager created in web-tmpnb to fix the linting error.

I'll need to update this PR soon.

Ping on this - do you want to update it?

Sure. I seem to have been very busy lately. I haven't forgotten about this.

Closing, as we have now moved to ESLint!

See #2657 and #2700 for more info.