Merge pull request swiftlang#150 from google/ternary-operator

Wrap ternary expressions.

Author: dabelknap

Diff for: Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -765,6 +765,12 @@ private final class TokenStreamCreator: SyntaxVisitor {
   }
 
   override func visit(_ node: TernaryExprSyntax) {
+    before(node.conditionExpression.firstToken, tokens: .open(.inconsistent, 2))
+    before(node.questionMark, tokens: .break)
+    after(node.questionMark, tokens: .space)
+    before(node.colonMark, tokens: .break)
+    after(node.colonMark, tokens: .space)
+    after(node.secondChoice.lastToken, tokens: .close)
     super.visit(node)
   }
 

Diff for: Tests/SwiftFormatPrettyPrintTests/TernaryExprTests.swift

@@ -0,0 +1,34 @@
+public class TernaryExprTests: PrettyPrintTestCase {
+  public func testTernaryExprs() {
+    let input =
+      """
+      let x = a ? b : c
+      let y = a ?b:c
+      let z = a
+        ? b
+        : c
+      let reallyLongName = a ? longTruePart : longFalsePart
+      let reallyLongName = reallyLongCondition ? reallyLongTruePart : reallyLongFalsePart
+      let reallyLongName = reallyLongCondition ? reallyReallyReallyLongTruePart : reallyLongFalsePart
+      """
+
+    let expected =
+      """
+      let x = a ? b : c
+      let y = a ? b : c
+      let z = a ? b : c
+      let reallyLongName =
+        a ? longTruePart : longFalsePart
+      let reallyLongName =
+        reallyLongCondition ? reallyLongTruePart
+          : reallyLongFalsePart
+      let reallyLongName =
+        reallyLongCondition
+          ? reallyReallyReallyLongTruePart
+          : reallyLongFalsePart
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
+}