no-ignored-replay-buffer not working when rxjs is imported as another alias

Trying to turn on the rxjs-no-ignored-replay-buffer and the rule fails for expressions like new Rx.ReplaySubject<number>(1); when rxjs is imported like such import * as Rx from 'rxjs';

After playing around with the two cases in the TSQuery playground and checking out the rxjsNoIgnoredReplayBufferRule.ts it seems that the rule does not work for this case.

Currently the rules’ logic gets the the direct parent of the Identifier i.e

const newExpression = identifier.parent as ts.NewExpression;

This works for cases where you’re just using the ReplaySubject directly const b = new ReplaySubject<string>(); , which has AST

But when rxjs is imported as an alias like import * as Rx from 'rxjs';, then the AST looks like this:

Which is a case that the current logic misses because it gets the direct parent of the Identifier node, and in this case, it is the PropertyAccessExpression node. Then it is trying to access the arguments property of the PropertyAccessExpression node, but we actually wanted the NewExpression node, another level up. But because we only get the direct parent of the Identifier, it cannot find that there is a buffer for this replay subject declaration.

Not sure what the best way to fix this is but I was thinking to have the tsquery be NewExpression:has(Identifier[name="ReplaySubject"]) to just get the actual NewExpression, so we wouldn’t lose its arguments, and then get the identifier text and location later?

Let me know what you think

[cartant]

You’re welcome to open a PR with the fix, if you have to time to do it.

[cartant]

Not sure what the best way to fix this is but I was thinking to have the tsquery be NewExpression:has(Identifier[name="ReplaySubject"]) to just get the actual NewExpression, so we wouldn’t lose its arguments, and then get the identifier text and location later?

The problem with that selector is that the ReplaySubject can be anywhere within the NewExpression. For example, that selector will find the outermost new in this expression:

new Thing(new Rx.ReplaySubject<number>(1));

I would go with a selector something like this:

NewExpression Identifier[name="ReplaySubject"], NewExpression PropertyAccessExpression Identifier[name="ReplaySubject"]

which should find the ReplaySubject in all of these use cases:

const a = new Thing(new Rx.ReplaySubject<number>(1));
const b = new Rx.ReplaySubject<number>(1);
const c = new ReplaySubject<number>(1);