use shared eslint-config-streamr-ts

[harbu]

Use shared eslint-config-stream-ts in line with streamr-dev/network#555. Had to add in a few additional rules to accommodate ongoing transition into TypeScript. Particularly rules:

• @typescript-eslint/ban-ts-comment many instances of @ts-expect-error without description. Not worth adding in descriptions imo since they will be most likely replaced with types later on.
• no-underscore-dangle again a lot of private fields leftover from javascript days, prolly worth changing when working on said code to prevent unexpected changes in behavior.
• There were a few require statements left. They were tactically placed, so I assumed they are most likely there on purpose. Annotated such with the following // eslint-disable-next-line import/no-unresolved.

[timoxley]

Previously this let + late declaration was required because it'd complain that onDisconnected was being used before it was defined, probably supposed to detect temporal deadzone e.g. in connection.off('disconnected', onDisconnected). I guess something just got smarter about this rather than the use-before-define detection or whatever being disabled?

[harbu]

To be honest I was a bit uneasy changing these, but assumed they should work. The previous version complained about using let:

/home/harbu/work/streamr-client-javascript/src/stream/utils.ts
  113:13  error  'onDisconnected' is never reassigned. Use 'const' instead  prefer-const

However it does feel a bit off referencing a symbol that only gets defined later on...

[timoxley]

same thing here

[harbu]

Well I checked and seems like TypeScript doesn't work any magic around this, the compiled output is

function waitFor(emitter, event) {
    return new Promise((resolve, reject) => {
        const onEvent = (value) => {
            emitter.off('error', onError);
            resolve(value);
        };
        const onError = (error) => {
            emitter.off(event, onEvent);
            reject(error);
        };
        emitter.once(event, onEvent);
        emitter.once('error', onError);
    });
}

[harbu]

Ah, we might wanna re-enable rule https://eslint.org/docs/rules/no-use-before-define @timoxley and revert these changes , agree?

[timoxley]

This // @ts-expect-error will probably go away with a resolve(undefined)

[timoxley]

These can actually probably be regular import calls.