ktlint_function_signature_body_expression_wrapping=always behavior question

[andrewparmet]

Expected Behavior

I'd like to format my multiline expression functions like so:

fun foo() =
    "bar"

fun foo(
    bar: BarBarBarBarBarBarBarBarBarBarBarBar,
    baz: BarBarBarBarBarBarBarBarBarBarBarBar,
    baf: BarBarBarBarBarBarBarBarBarBarBarBar,
    bag: BarBarBarBarBarBarBarBarBarBarBarBar,
) =
    Foo(
        bar = bar,
        baz = baz
    )

Observed Behavior

Instead the second declaration is formatted as:

fun foo(
    bar: BarBarBarBarBarBarBarBarBarBarBarBar,
    baz: BarBarBarBarBarBarBarBarBarBarBarBar,
    baf: BarBarBarBarBarBarBarBarBarBarBarBar,
    bag: BarBarBarBarBarBarBarBarBarBarBarBar,
) = Foo(
    bar = bar,
    baz = baz
)

Steps to Reproduce

My editorconfig has ktlint_function_signature_body_expression_wrapping = always and a max line length to force this parameter list to wrap. The expression wrapping works when the function declaration is a single line (the first function declaration) but not when the function declaration spans lines (the second). Is it possible to achieve what I'm looking for? Thanks!

Your Environment

• Version of ktlint used: 1.4.1
• Relevant parts of the .editorconfig settings:

        "max_line_length" to 120,
        "ktlint_class_signature_rule_force_multiline_when_parameter_count_greater_or_equal_than" to 1,
        "ktlint_function_signature_body_expression_wrapping" to "always",

• Name and version (or code for custom task) of integration used (Gradle plugin, Maven plugin, command line, custom Gradle task): Spotless v7 beta 3
• Version of Gradle used (if applicable): 8.10
• Operating System and version: Mac

[paul-dingemans]

If I recall correctly it is a deliberate exception to not wrap in case the closing parenthesis starts on a newline and has no return type. Reasoning was that the body expression looks a bit "lost" as its indentation is equal to the start position when lines are merged (of course given the widely accepted standard of 4 spaces for indentation):

) =
    Foo(

vs

) = Foo(

I do understand that this exception feels weird when .editorconfig property ktlint_function_signature_body_expression_wrapping is set to always. Let me double check this.

[andrewparmet]

Thanks - all of our code is consistently formatted with wrapped expression function bodies and this forces us to be inconsistent in the majority of cases (where we omit the return type).