Multi-line object being formatted into one line if max line limit isn't exceeded.

[jtodd3]

Prettier 2.3.2
Playground link

--parser typescript
--print-width 120
--single-quote
--prose-wrap always

Input:

interface MyInterface {
  foo(): string,
}

export abstract class Foo implements MyInterface {
  foo() {
    const value = {};
    const {
      property1,
      property2,
      property3,
      property4,
      property5,
    } = value;
    return '';
  }
}

Output:

interface MyInterface {
  foo(): string;
}

export abstract class Foo implements MyInterface {
  foo() {
    const value = {};
    const { property1, property2, property3, property4, property5 } = value;
    return '';
  }
}

Expected behavior:
Prior to 2.3.0 the input example would not be formatted into the output example, Prettier didn't turn the multi-line object into a single-line statement. The expected behaviour only happens when we exceed the max line width (120 in our case)

[thorn0]

Prior to 2.3.0 the input example would not be formatted into the output example

It would. Just tested it with older versions.

The expected behaviour only happens when we exceed the max line width (120 in our case)

That's how Prettier works in general. Note that object destructurings and object literals are not the same. Prettier has always formatted them differently. The current formatting looks good enough for a comma-separated list of identifiers, so it's unlikely to change. E.g., compare it to how function arguments (another comma-separated list) are formatted. If the line looks too long to you, it probably is, so try reducing printWidth (see the recommendations here).

I'm going to close this as "works as intended".

[jtodd3]

I understand how Prettier works, my issue is why did the behavior change from 2.2.1 to 2.3.0 though?

edit: also for context we're using Prettier to format our team's frontend monorepo, we decided to go with a printWidth 120 so advising to change the printWidth doesn't really help.

[brodybits]

why did the behavior change from 2.2.1 to 2.3.0

I tried your input with Prettier 2.2.1 (actually PR #9741 which came very soon before Prettier 2.2.1), seems to be no different:

Prettier pr-9741
Playground link

--parser typescript
--print-width 120
--prose-wrap always
--single-quote

Input:

interface MyInterface {
  foo(): string,
}

export abstract class Foo implements MyInterface {
  foo() {
    const value = {};
    const {
      property1,
      property2,
      property3,
      property4,
      property5,
    } = value;
    return '';
  }
}

Output:

interface MyInterface {
  foo(): string;
}

export abstract class Foo implements MyInterface {
  foo() {
    const value = {};
    const { property1, property2, property3, property4, property5 } = value;
    return '';
  }
}