Swiftlint: False positives when using let_var_whitespace with string interpolation

[konomae]

New Issue Checklist

• [x] Updated SwiftLint to the latest version
• [x] I searched for existing GitHub issues

Describe the bug

False positives when using let_var_whitespace with string interpolation.

swiftlint version  
0.32.0

.swiftlint.yml

whitelist_rules:
  - let_var_whitespace

main.swift
(maybe, false positive)

let a = "\(1)"
private let b = "" // Variable Declaration Whitespace Violation: Let and var should be separated from other statements by a blank line. (let_var_whitespace)

If I remove string interpolation from the code, no violation found.

let a = ""
private let b = "" // OK

Or removing private from second line is also no violation.

let a = "\(1)"
let b = "" // OK

Complete output when running SwiftLint, including the stack trace and command used

$ swiftlint lint
Loading configuration from '.swiftlint.yml'
Linting Swift files at paths 
Linting 'main.swift' (1/1)
/path/to/main.swift:2:1: warning: Variable Declaration Whitespace Violation: Let and var should be separated from other statements by a blank line. (let_var_whitespace)
Done linting! Found 1 violation, 0 serious in 1 file.

Environment

• SwiftLint version (run swiftlint version to be sure)? 0.32.0
• Installation method used (Homebrew, CocoaPods, building from source, etc)? homebrew
• Paste your configuration file:

whitelist_rules:
  - let_var_whitespace

[marcelofabri]

This is caused by a SourceKit bug: https://github.com/realm/SwiftLint/pull/2720#issuecomment-483112662

[marcelofabri]

Looks like this was fixed as part of Swift 5.1 💯