Rewrite SyntacticSugarRule with SwiftSyntax

CHANGELOG.md

@@ -104,6 +104,9 @@
 #### Experimental
 
 * None.
+* Fix incorrect autocorrection in `syntactic_sugar` rule 
+  [Paul Taykalo](https://github.com/PaulTaykalo)
+  [#3866](https://github.com/realm/SwiftLint/issues/3866)
 
 #### Enhancements
 

CONTRIBUTING.md

@@ -55,7 +55,6 @@ $ xcodebuild -scheme swiftlint test
 $ swift test
 $ make docker_test
 ```
-
 ## Rules
 
 New rules should be added in the `Source/SwiftLintFramework/Rules` directory.
@@ -72,6 +71,19 @@ over time. This way adding a unit test for your new Rule is just a matter of
 adding a test case in `RulesTests.swift` which simply calls
 `verifyRule(YourNewRule.description)`.
 
+For debugging purposes examples can be marked as `focused`. If there are any
+focused examples found, then only those will be run when running tests.
+```
+nonTriggeringExamples: [
+    Example("let x: [Int]"),
+    Example("let x: [Int: String]").focused()   // only this one will be run in tests
+],
+triggeringExamples: [
+    Example("let x: ↓Array<String>"),
+    Example("let x: ↓Dictionary<Int, String>")
+]
+```
+
 ### `ConfigurationProviderRule`
 
 If your rule supports user-configurable options via `.swiftlint.yml`, you can

Source/SwiftLintFramework/Extensions/StringView+SwiftSyntax.swift

@@ -0,0 +1,25 @@
+import Foundation
+import SourceKittenFramework
+import SwiftSyntax
+
+extension StringView {
+    /// Converts two absolute positions from SwiftSyntax  to valid NSRange if possible
+    /// - Parameters:
+    ///   - start: starting poisiition
+    ///   - end: end position
+    /// - Returns: NSRange or nil in case of empty string
+    func NSRange(start: AbsolutePosition, end: AbsolutePosition) -> NSRange? {
+        precondition(end.utf8Offset >= start.utf8Offset, "End position should be beigger than start position")
+        return NSRange(start: start, length: end.utf8Offset - start.utf8Offset)
+    }
+
+    /// Converts absolute position with length from SwiftSyntax  to valid NSRange if possible
+    /// - Parameters:
+    ///   - start: starting position
+    ///   - length: length in bytes
+    /// - Returns: NSRange or nil in case of empty string
+    private func NSRange(start: AbsolutePosition, length: Int) -> NSRange? {
+        let byteRange = ByteRange(location: ByteCount(start.utf8Offset), length: ByteCount(length))
+        return byteRangeToNSRange(byteRange)
+    }
+}