Convert lit-based syntax classification tests to XCTests

Author: StevenWong12

Sources/SwiftIDEUtils/SyntaxClassification.swift

@@ -66,7 +66,7 @@ extension SyntaxClassification {
   internal static func classify(_ keyPath: AnyKeyPath) -> (SyntaxClassification, Bool)? {
     switch keyPath {
     case \AttributeSyntax.attributeName:
-      return (.attribute, false)
+      return (.attribute, true)
     case \PlatformVersionItemSyntax.availabilityVersionRestriction:
       return (.keyword, false)
     case \AvailabilityVersionRestrictionSyntax.platform:

Sources/SwiftIDEUtils/SyntaxClassifier.swift

@@ -196,12 +196,37 @@ private struct ClassificationVisitor {
 
     for case (let index, let child?) in children.enumerated() {
 
-      let classification: (SyntaxClassification, Bool)?
+      let classification: (classification: SyntaxClassification, force: Bool)?
       if case .layout(let layout) = descriptor.node.kind.syntaxNodeType.structure {
         classification = SyntaxClassification.classify(layout[index])
       } else {
         classification = nil
       }
+
+      if let classification, classification.force {
+        // Leading trivia.
+        report(range: SyntaxClassifiedRange(kind: .none, range: ByteSourceRange(offset: byteOffset, length: child.leadingTriviaByteLength)))
+        // Layout node text.
+        let range = SyntaxClassifiedRange(
+          kind: classification.classification,
+          range: ByteSourceRange(
+            offset: byteOffset + child.leadingTriviaByteLength,
+            length: child.byteLength - child.leadingTriviaByteLength - child.trailingTriviaByteLength
+          )
+        )
+        report(range: range)
+        // Trailing trivia.
+        report(
+          range: SyntaxClassifiedRange(
+            kind: .none,
+            range: ByteSourceRange(offset: byteOffset + child.byteLength - child.trailingTriviaByteLength, length: child.trailingTriviaByteLength)
+          )
+        )
+
+        byteOffset += child.byteLength
+        continue
+      }
+
       let result = visit(
         .init(
           node: child,

Tests/SwiftIDEUtilsTest/Assertions.swift

@@ -71,7 +71,7 @@ func assertClassification(
       line: spec.line
     )
 
-    lastRangeUpperBound = source.index(source.startIndex, offsetBy: range.endOffset)
+    lastRangeUpperBound = source.utf8.index(source.utf8.startIndex, offsetBy: range.endOffset)
   }
 }