Unwanted whitespaces added to AccessorMacro expansion

[neothXT]

Description
I've been playing around with macros and I found myself in a situation where I got attached accessor macro with 2 parameters - url and method. Both are strings.
It looks like this

public struct MyMacroMacro: AccessorMacro {
    public static func expansion<Context, Declaration>(
        of node: AttributeSyntax,
        providingAccessorsOf declaration: Declaration,
        in context: Context
    ) throws -> [AccessorDeclSyntax] where Context : MacroExpansionContext, Declaration : DeclSyntaxProtocol {
        guard let expressions = node.argument?.as(TupleExprElementListSyntax.self) else {
            //TODO throw error
            return []
        }
    
        let segments = expressions.compactMap { $0.expression.as(StringLiteralExprSyntax.self)?.segments }
        let params = segments.compactMap { $0.trimmedDescription }
    
        guard params.count == 2 else {
            //TODO throw error
            return []
        }
    
        return [
            """
            .init(url: url + "\(raw: params[0])", method: "\(raw: params[1])")
            """
        ]
    }
}

Now, when I call it like:
struct MyStruct { let url = "https://apple.com" @MyMacro(url: "/test", method: "some") var myVar: MyCustomType

it produces something like this:
struct MyStruct { let url = "https://apple.com" var myVar: MyCustomType { .init(url: url + " /test", method: " some") }

I have even tried hardcoding the return of AccessorMacro to produce .init(url: url + "/test", method: "get") but it still added those white spaces.

Steps to reproduce
Create accessor macro that'll return something - let it be dictionary or an initializer - with some string inside.

Expected behavior
I want to have my code generated without unwanted white spaces.

Environment
Swift 5.9
Xcode 15.0

[AnthonyLatsis]

@ahoppen This is probably a swift-syntax issue.

[ahoppen]

The issue here is that the following is not a valid AccessorDeclSyntax, it has a required accessorKind child.

.init(url: url + "\(raw: params[0])", method: "\(raw: params[1])")

You will need to write

get {
  .init(url: url + "\(raw: params[0])", method: "\(raw: params[1])")
}

[neothXT]

You're right. It works! Thank you very much for such quick response <3

[ahoppen]

FWIW I’m hoping to make these kinds issues easier to discover with #1790. Do you think a log in Xcode’s console would have helped you find the issue yourself?

[ParseError] Parsing a `AccessorDeclSyntax` node from string interpolation produced the following parsing errors.
Set a brakpoint in `SyntaxParseable.logStringInterpolationParsingError()` to debug the failure.
1 │ .init(url: url + "/test", method: "some")
  │ ├─ error: expected 'get' in accessor
  │ ╰─ error: unexpected code '.init(url: url + "/test", method: "some")' before accessor

[AnthonyLatsis]

@ahoppen Since this is not a bug but was reported as an issue in swift-syntax, could we transfer it?

[ahoppen]

Transferrd