ESLint and thus eslint-plugin-vue only has access to the current file while linting, so checking what might be returned from some other file is difficult.

Maybe if typescript-eslint's parser is used, we have access to the types and can report those cases then? Feel free to try that and submit a PR.

I have a similar problem. Based on the comment above, for the test I made a composable in one file

My example of playback:

import { defineComponent, ref } from 'vue'

const useMyRef = () => ref(true)

export const TestComponent = defineComponent({
	name: 'TestComponent',
	setup() {
		const test2 = ref(true)
		const ctx = useMyRef()

		// Not valid - true
		if (test2) {
			console.log('')
		}

		// Valid - wtf?
		if (ctx) {
			console.log('')
		}

		return () => null
	},
})

Same error here. This is an important feature for me, but I haven’t been able to resolve it. Happy to offer $10-30 in crypto to support whoever fixes it