minor refinements

Sources/EnumeratorMacroImpl/MacroError.swift

@@ -79,7 +79,7 @@ enum MacroError: Error, CustomStringConvertible {
         case let .declaredHere(name):
             "\(name) declared here:"
         case .redundantKeyValuesFunctionCall:
-            "Redundant 'keyValues' function used. The array is already of type '\(EArray<EKeyValue>.self)'"
+            "Redundant 'keyValues' function used. The array is already of type '[KeyValue]'"
         }
     }
 }

Sources/EnumeratorMacroImpl/Visitors/ExcessiveTriviaRemover.swift

@@ -1,18 +1,21 @@
 import SwiftSyntax
 
 final class ExcessiveTriviaRemover: SyntaxRewriter {
-    /// Remove empty lines.
+    /// Removes empty lines.
     override func visitAny(_ node: Syntax) -> Syntax? {
         var node = node
         let leadingModified, trailingModified: Bool
-        (leadingModified, node) = self.handleTrivia(node, at: \.leadingTrivia)
-        (trailingModified, node) = self.handleTrivia(node, at: \.trailingTrivia)
+        (leadingModified, node) = self.removeEmptyLineTrivia(from: node, at: \.leadingTrivia)
+        (trailingModified, node) = self.removeEmptyLineTrivia(from: node, at: \.trailingTrivia)
         let modified = leadingModified || trailingModified
+        /// Recursively call `rewrite(_:)` if we are not returning `nil`.
+        /// Because `SyntaxRewriter`'s implementation will skip
+        /// calling `visitAny(_:)` on the children of the node.
         return modified ? self.rewrite(node) : nil
     }
 
-    func handleTrivia(
-        _ node: Syntax,
+    func removeEmptyLineTrivia(
+        from node: Syntax,
         at keyPath: WritableKeyPath<Syntax, Trivia>
     ) -> (modified: Bool, syntax: Syntax) {
         var node = node
@@ -29,7 +32,7 @@ final class ExcessiveTriviaRemover: SyntaxRewriter {
                 if previousWasNewLines,
                    idx + 1 < pieces.count,
                    case .newlines = pieces[idx + 1] {
-                    /// Previous and next are both `newlines`.
+                    /// Previous and next are both `newlines`, so remove this `spaces`.
                     toBeRemoved.append(idx)
                 }
                 previousWasNewLines = false

Sources/EnumeratorMacroImpl/Visitors/SwitchErrorsRewriter.swift

@@ -1,6 +1,26 @@
 import SwiftSyntax
 
 final class SwitchErrorsRewriter: SyntaxRewriter {
+    /// Rewrites and removes the trailing comma of the last case which is an error in Swift.
+    /// For example, it rewrites:
+    /// ```swift
+    /// switch self {
+    /// case
+    ///     .a,
+    ///     .b,
+    ///     :
+    ///     return x
+    /// ```
+    /// to:
+    /// ```swift
+    /// switch self {
+    /// case
+    ///     .a,
+    ///     .b
+    ///     :
+    ///     return x
+    /// ```
+    /// so it removes the `,` after `b` which is the last case.
     override func visit(_ node: SwitchCaseSyntax) -> SwitchCaseSyntax {
         guard let label = node.label.as(SwitchCaseLabelSyntax.self) else {
             return node

Tests/EnumeratorMacroTests/EnumeratorMacroTests.swift

@@ -579,7 +579,7 @@ final class EnumeratorMacroTests: XCTestCase {
                 domain: "EnumeratorMacro.MacroError",
                 id: "redundantKeyValuesFunctionCall"
             ),
-            message: "Redundant 'keyValues' function used. The array is already of type 'EArray<EKeyValue>'",
+            message: "Redundant 'keyValues' function used. The array is already of type '[KeyValue]'",
             line: 1,
             column: 13,
             severity: .error