[no-duplicates] Bad auto fix for typescript

[latin-1]

Regardless of the prefer-inline option.

Input

import type { A } from "./mod";
import { type B, C } from "./mod";

Output

import type { A, type B, C } from "./mod";

cc @snewcomer

[snewcomer]

@latin-1 Thanks for the issue! Yes, it doesn't look like it is performing correctly. Both the type and inline type specifiers for an import statement are not allowed. Looking at this and a few other issues today.

https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBDAnmApnA3nAggGgctAITgF84AzKCEOAcgDoB6ECAE1oG4g

If prefer-inline: true, I'm guessing it should look like this

import { type A, type B, C } from "./mod";

If it is false or not specified, it should stay the same.

import type { A } from "./mod";
import { type B, C } from "./mod";

source of error - https://github.com/import-js/eslint-plugin-import/pull/2475/files#r1089976521

[snewcomer]

Furthermore, I wonder if instead we should make our best effort to collapse.

prefer-inline false

import type { A, B } from "./mod";
import { C } from "./mod";

or depending on the order of the original

import { C } from "./mod";
import type { A, B } from "./mod";

• note about the code I have come to learn. The ‘first, rest imports’ doesn’t necessarily work too well when dealing with with deduping type imports.

The easier case to handle is prefer-inline true. However, if false, this isn’t terribly hard to handle as well. The above example shows that we could pull all inline types and type imports from other Type/InlineType ImportDeclarations to the first Type ImportDeclaration and leave the Value ImportDeclarations to their own import statement. The flexibility here is important esp when considering many (>2) duplicate import statements in any order - maybe the value import is first, maybe the type import is first.

[snewcomer]

@ljharb Hi Jordan. So basically I have a POC to fix this issue but also make the process of collapsing ‘type’ duplicates more flexible. The original solution I did was entirely inflexible :). I was hoping to either get alignment for the previous comment code block, whether you wanted more explanation, or if you felt it should go elsewhere.

[ljharb]

Yes, I think it would be ideal to maximally collapse, preserving order as best as can be (import/order can clean that up further).

[dylang]

Possibly related: #2792