Added commentValues on Trivia

This holds an array of comments made from the trivia's pieces, with
one line per element of the array

Author: adammcarter

Sources/SwiftSyntax/Trivia.swift

@@ -42,6 +42,21 @@ public struct Trivia: Sendable {
     pieces.isEmpty
   }
 
+  /// The string contents of all the comment pieces with any comments tokens trimmed.
+  ///
+  /// Each element in the array is the trimmed contents of a line comment, or, in the case of a multi-line comment a trimmed, concatenated single string.
+  public var commentValues: [String] {
+    pieces.compactMap {
+      switch $0 {
+      case .lineComment(let text), .docLineComment(let text):
+        sanitizingLineComment(text)
+
+      default:
+        nil
+      }
+    }
+  }
+
   /// The length of all the pieces in this ``Trivia``.
   public var sourceLength: SourceLength {
     return pieces.map({ $0.sourceLength }).reduce(.zero, +)
@@ -215,3 +230,19 @@ extension RawTriviaPiece: CustomDebugStringConvertible {
     TriviaPiece(raw: self).debugDescription
   }
 }
+
+private func sanitizingLineComment(_ text: String) -> String {
+  // TODO: adammcarter - can we import Foundation instead and use trimmingCharacters(in:)
+
+  var charactersToDrop = 0
+
+  for character in text {
+    if (character == "/" || character == " ") {
+      charactersToDrop += 1
+    } else {
+      break
+    }
+  }
+
+  return String(text.dropFirst(charactersToDrop))
+}

Tests/SwiftSyntaxTest/TriviaTests.swift

@@ -69,4 +69,86 @@ class TriviaTests: XCTestCase {
     XCTAssertNotEqual(TriviaPiece.unexpectedText("e"), .unexpectedText("f"))
     XCTAssertNotEqual(TriviaPiece.unexpectedText("e"), .lineComment("e"))
   }
+
+  func testTriviaCommentValues() {
+    XCTAssertTrue(Trivia(pieces: []).commentValues.isEmpty)
+
+    // MARK: line comment
+
+    XCTAssertEqual(
+      Trivia(pieces: [.lineComment("")]).commentValues,
+      [""]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [.lineComment("Some line comment")]).commentValues,
+      ["Some line comment"]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [.lineComment("// Some line comment")]).commentValues,
+      ["Some line comment"]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [
+        .lineComment("// Some line comment"),
+        .lineComment("// Another"),
+      ]).commentValues,
+      [
+        "Some line comment",
+        "Another",
+      ]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [
+        .lineComment("// Some line comment"),
+        .lineComment("Other"),
+      ]).commentValues,
+      [
+        "Some line comment",
+        "Other",
+      ]
+    )
+
+    // MARK: doc line comment
+
+    XCTAssertEqual(
+      Trivia(pieces: [.docLineComment("")]).commentValues,
+      [""]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [.docLineComment("Some doc line comment")]).commentValues,
+      ["Some doc line comment"]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [.docLineComment("/// Some doc line comment")]).commentValues,
+      ["Some doc line comment"]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [
+        .docLineComment("/// Some doc line comment"),
+        .docLineComment("/// Another"),
+      ]).commentValues,
+      [
+        "Some doc line comment",
+        "Another",
+      ]
+    )
+
+    XCTAssertEqual(
+      Trivia(pieces: [
+        .docLineComment("/// Some doc line comment"),
+        .docLineComment("Other"),
+      ]).commentValues,
+      [
+        "Some doc line comment",
+        "Other",
+      ]
+    )
+  }
 }