GeezerVison

FYI the PR description claims "Fixes #47807", but this PR has number 47807

This feels really wrong 😕

The proposal explicitly says that import assertions must not affect how a module is evaluated or resolved:

[...]
The implementation of HostResolveImportedModule must conform to the following requirements:

• [...]
• moduleRequest.[[Assertions]] must not influence the interpretation of the module or the module specifier; instead, it may be used to determine whether the algorithm completes normally or with an abrupt completion.

In other words, if both these two imports succeed they must resolve/evaluate the same file:

import { A } from "pkg" assert { "resolution-mode": "require" };
import { A } from "pkg" assert { "resolution-mode": "import" };

The imports assertions proposal even mentions a possible follow-up proposal that would allow what you need, but it would be a separate proposal (with likely different syntax).

I know that this PR is only about import type so it's technically "just TS" and not JS, but actively going against the JS semantics should be discouraged.

https://github.com/tc39/proposal-import-reflection is probably what you need, even if it's not clear yet if it's also meant to affect resolution.

These don't affect runtime and are type-only (your example above doesn't work - you have to say import type); it's fine - it's much better than introducing full on new syntax.

it's fine - it's much better than introducing full on new syntax.

Wesley Wigham (@weswigham) This is wrong, we're using the assert keyword for something that isn't an assertion. Why? You're correct that this is a type-only statement, all the more reason to do literally anything else and not misuse a JS syntax.

There are plenty of other options that make sense without completely new and ts-only syntax e.g.

// comment directive, nothing new

// @ts-resolution=require
import type { RequireInterface } from "pkg";

// https://github.com/tc39/proposal-import-reflection

import type { RequireInterface } from "pkg" as "resolution=require";

// dangles off the already ts-only part

import type(resolution=require) { RequireInterface } from "pkg";

Please consider reverting this change.

I've already seen a lot of people confused by import assertions and what they could be used for in runtimes, specifically conflating them with what's proposed in https://github.com/tc39/proposal-import-reflection. It would be a shame to see TS fostering that misconception, or perhaps falling victim to it.

Why is it:

assert {"resolution-mode": "import"};

(requiring quotes), and not:

assert {resolutionMode: "import"};

?

Consistency with the triple-slash reference form and a bit of extra syntax encumbrance to make you pause and think if you really need to use it. :)

Would this also hypothetically help solve the issue found at #46213 ? If so, how soon do you think this feature will graduate from nightly?