Organize imports doesn't keep imports in a vertical column

[jakebailey]

After reformatting this repo's imports as vertical sorted columns for better merge conflict handling, we noticed that running organize imports produced an odd result. Given this test:

/// <reference path="fourslash.ts" />

////import {
////    Type1,
////    Type2,
////    func4,
////    Type3,
////    Type4,
////    Type5,
////    Type7,
////    Type8,
////    Type9,
////    func1,
////    func2,
////    Type6,
////    func3,
////    func5,
////    func6,
////    func7,
////    func8,
////    func9,
////} from "foo";
////interface Use extends Type1, Type2, Type3, Type4, Type5, Type6, Type7, Type8, Type9 {}
////console.log(func1, func2, func3, func4, func5, func6, func7, func8, func9);

verify.organizeImports(
`import {
    func1,
    func2,
    func3,
    func4,
    func5,
    func6,
    func7,
    func8,
    func9,
    Type1,
    Type2,
    Type3,
    Type4,
    Type5,
    Type6,
    Type7,
    Type8,
    Type9,
} from "foo";
interface Use extends Type1, Type2, Type3, Type4, Type5, Type6, Type7, Type8, Type9 {}
console.log(func1, func2, func3, func4, func5, func6, func7, func8, func9);`
);

Organize imports gives:

import {
    func1,
    func2, func3, func4, func5,
    func6,
    func7,
    func8,
    func9, Type1,
    Type2, Type3,
    Type4,
    Type5, Type6, Type7,
    Type8,
    Type9
} from "foo";
interface Use extends Type1, Type2, Type3, Type4, Type5, Type6, Type7, Type8, Type9 {}
console.log(func1, func2, func3, func4, func5, func6, func7, func8, func9)

[fatcerberus]

That’s weird, there doesn’t seem to be any rhyme or reason for how it decides to add a line break or not.

[jakebailey]

I suspect this to be something related to #51301, but for reorderings.

[andrewbranch]

Thanks for the fourslash test!

there doesn’t seem to be any rhyme or reason for how it decides to add a line break or not.

The pattern of line breaks spells out “send help, formatting-aware code transforms are hard” in Morse code

[andrewbranch]

For the curious, it’s preserving the line break between elements that are consecutive both before and after the sorting.

[fatcerberus]

Ah, I was confused because I assumed the string passed to verify.organizeImports was the input string, not the expected output. Everything was already in the expected order there so it seemed like it just randomly deleted some line breaks. I now realize the input string is the fourslash comments and feel dumb.