Merge pull request swiftlang#135 from dabelknap/block-comments

Add support for block comments

Author: allevato

Sources/SwiftFormatPrettyPrint/Comment.swift

@@ -21,45 +21,53 @@ struct Comment {
     /// The length of the characters starting the comment.
     var prefixLength: Int {
       switch self {
-      // `//`, `/*`, and `/**` all will have their continued lines prefixed with 3 characters.
-      case .line, .block, .docBlock: return 2
-
-      // `/// ` is 4 characters.
-      case .docLine: return 3
+      // `//`, `/*`
+      case .line, .block: return 2
+      // `///`, `/**`
+      case .docLine, .docBlock: return 3
       }
     }
 
     var prefix: String {
       switch self {
       case .line: return "//"
-      case .block, .docBlock: return " "
+      case .block: return "/*"
+      case .docBlock: return "/**"
       case .docLine: return "///"
       }
     }
   }
+
   let kind: Kind
   var text: [String]
   public var length: Int
 
   init(kind: Kind, text: String) {
-    self.text = [text]
     self.kind = kind
-    self.length = text.count + kind.prefixLength + 1
-
-    self.text[0].removeFirst(kind.prefixLength)
-
     switch kind {
-    case .docBlock:
-      self.text.removeLast(2)
-    case .block:
-      self.text.removeLast(2)
-    default: break
+    case .line, .docLine:
+      self.text = [text]
+      self.text[0].removeFirst(kind.prefixLength)
+      self.length = self.text.reduce(0, { $0 + $1.count + kind.prefixLength + 1 })
+
+    case .block, .docBlock:
+      var fulltext: String = text
+      fulltext.removeFirst(kind.prefixLength)
+      fulltext.removeLast(2)
+      self.text = fulltext.split(separator: "\n", omittingEmptySubsequences: false).map{ String($0) }
+      self.length = self.text.reduce(0, { $0 + $1.count }) + kind.prefixLength + 3
     }
   }
 
   func print(indent: Int) -> String {
-    let separator = "\n" + String(repeating: " ", count: indent) + kind.prefix
-    return kind.prefix + self.text.joined(separator: separator)
+    switch self.kind {
+    case .line, .docLine:
+      let separator = "\n" + String(repeating: " ", count: indent) + kind.prefix
+      return kind.prefix + self.text.joined(separator: separator)
+    case .block, .docBlock:
+      let separator = "\n" + String(repeating: " ", count: indent)
+      return kind.prefix + self.text.joined(separator: separator) + "*/"
+    }
   }
 
   mutating func addText(_ text: [String]) {

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -1262,6 +1262,17 @@ private final class TokenStreamCreator: SyntaxVisitor {
           }
           return
         }
+      case .blockComment(let text):
+        if offset > 0, case .newlines? = trivia[safe: offset - 1] {
+          return
+        } else {
+          appendToken(.break(size: 2, offset: 2))
+          appendToken(.comment(Comment(kind: .block, text: text)))
+          if let parent = nextToken.parent?.parent, !(parent is CodeBlockItemSyntax) {
+            appendToken(.newline)
+          }
+          return
+        }
       default:
         break
       }
@@ -1279,6 +1290,14 @@ private final class TokenStreamCreator: SyntaxVisitor {
           appendToken(.comment(Comment(kind: .line, text: text)))
           appendToken(.newline)
         }
+      case .blockComment(let text):
+        if fileStart {
+          appendToken(.comment(Comment(kind: .block, text: text)))
+          appendToken(.newline)
+        } else if offset > 0, case .newlines? = trivia[safe: offset - 1] {
+          appendToken(.comment(Comment(kind: .block, text: text)))
+          appendToken(.newline)
+        }
       case .docLineComment(let text):
         appendToken(.comment(Comment(kind: .docLine, text: text)))
         if case .newlines? = trivia[safe: offset + 1],
@@ -1287,6 +1306,14 @@ private final class TokenStreamCreator: SyntaxVisitor {
         } else {
           appendToken(.newline)
         }
+      case .docBlockComment(let text):
+        appendToken(.comment(Comment(kind: .docBlock, text: text)))
+        if case .newlines? = trivia[safe: offset + 1],
+          case .docLineComment? = trivia[safe: offset + 2] {
+          /* do nothing */
+        } else {
+          appendToken(.newline)
+        }
       case .newlines(let n), .carriageReturns(let n), .carriageReturnLineFeeds(let n):
         if n > 1 {
           appendToken(.newlines(min(n - 1, config.maximumBlankLines), offset: 0))

Tests/SwiftFormatPrettyPrintTests/CommentTests.swift

@@ -128,6 +128,14 @@ public class CommentTests: PrettyPrintTestCase {
       // Dictionary comment
       let b = ["abc": 456, // small comment
         "def": 789]
+
+      /* Array comment */
+      let a = [456, /* small comment */
+        789]
+
+      /* Dictionary comment */
+      let b = ["abc": 456, /* small comment */
+        "def": 789]
       """
 
     let expected =
@@ -144,8 +152,143 @@ public class CommentTests: PrettyPrintTestCase {
         "def": 789
       ]
 
+      /* Array comment */
+      let a = [
+        456,  /* small comment */
+        789
+      ]
+
+      /* Dictionary comment */
+      let b = [
+        "abc": 456,  /* small comment */
+        "def": 789
+      ]
+
       """
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 80)
   }
+
+  public func testDocumentationBlockComments() {
+    let input =
+      """
+      /** This is a documentation comment
+       *
+       * - Parameters:
+       *   - param1: Param1 comment
+       *   - param2: Param2 comment
+       * - Returns: The output
+      **/
+      func myfun(param1: Int, param2: Double) -> String {
+        let out = "123"
+        return out
+      }
+
+      /** A brief doc comment **/
+      func myfun() {
+        let a = 123
+        let b = "456"
+      }
+
+      public class MyClass {
+        /** Doc comment **/
+        var myVariable: Int
+
+        /** Method doc comment
+         *
+         * - Parameters:
+         *   - param1: Param1 comment
+         *   - param2: Param2 comment
+         * - Returns: The output
+        **/
+        func myFun(param1: Int, param2: Int) -> String {
+          let a = 123
+          let b = "456"
+          return b
+        }
+      }
+      """
+
+    let expected =
+      """
+      /** This is a documentation comment
+       *
+       * - Parameters:
+       *   - param1: Param1 comment
+       *   - param2: Param2 comment
+       * - Returns: The output
+      **/
+      func myfun(param1: Int, param2: Double) -> String {
+        let out = "123"
+        return out
+      }
+
+      /** A brief doc comment **/
+      func myfun() {
+        let a = 123
+        let b = "456"
+      }
+
+      public class MyClass {
+        /** Doc comment **/
+        var myVariable: Int
+
+        /** Method doc comment
+         *
+         * - Parameters:
+         *   - param1: Param1 comment
+         *   - param2: Param2 comment
+         * - Returns: The output
+        **/
+        func myFun(param1: Int, param2: Int) -> String {
+          let a = 123
+          let b = "456"
+          return b
+        }
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 55)
+  }
+
+  public func testBlockComments() {
+    let input =
+      """
+      /* Line Comment1 */
+      /* Line Comment2 */
+      let a = 123
+      let b = "456"  /* End of line comment */
+      let c = "More content"
+
+      /* Comment 3
+         Comment 4 */
+
+      let reallyLongVariableName = 123  /* This comment should wrap */
+
+      let d = 123
+      /* Trailing Comment */
+      """
+
+    let expected =
+      """
+      /* Line Comment1 */
+      /* Line Comment2 */
+      let a = 123
+      let b = "456"  /* End of line comment */
+      let c = "More content"
+
+      /* Comment 3
+         Comment 4 */
+
+      let reallyLongVariableName = 123
+        /* This comment should wrap */
+
+      let d = 123
+      /* Trailing Comment */
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
 }