Merge pull request swiftlang#181 from dabelknap/associatedtype

Support associated types

Author: allevato

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -1232,6 +1232,15 @@ private final class TokenStreamCreator: SyntaxVisitor {
   }
 
   override func visit(_ node: AssociatedtypeDeclSyntax) {
+    if let attributes = node.attributes {
+      before(node.firstToken, tokens: .space(size: 0), .open(.consistent, 0))
+      after(attributes.lastToken, tokens: .open)
+    } else {
+      before(node.firstToken, tokens: .space(size: 0), .open(.consistent, 0), .open)
+    }
+    after(node.lastToken, tokens: .close, .close)
+    after(node.associatedtypeKeyword, tokens: .break)
+    before(node.genericWhereClause?.firstToken, tokens: .break)
     super.visit(node)
   }
 

Tests/SwiftFormatPrettyPrintTests/ProtocolDeclTests.swift

@@ -189,4 +189,41 @@ public class ProtocolDeclTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 30)
   }
+
+  public func testProtocolWithAssociatedtype() {
+    let input =
+      """
+      protocol MyProtocol {
+        var A: Int
+
+        associatedtype TypeOne
+
+        associatedtype TypeTwo: AnotherType
+
+        associatedtype TypeThree: SomeType where TypeThree.Item == Item
+
+        @available(swift 4.0)
+        associatedtype TypeFour
+      }
+      """
+
+    let expected =
+      """
+      protocol MyProtocol {
+        var A: Int
+
+        associatedtype TypeOne
+
+        associatedtype TypeTwo: AnotherType
+
+        associatedtype TypeThree: SomeType where TypeThree.Item == Item
+
+        @available(swift 4.0)
+        associatedtype TypeFour
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 65)
+  }
 }