Fix compile error caused by wildcard argument usage (#130)

* Fix compile error caused by wildcard argument usage

* Apply suggestions from code review

---------

Co-authored-by: hanjun-yu <[email protected]>
Co-authored-by: Stephen Celis <[email protected]>

Author: 3 people

Sources/CasePathsMacros/CasePathableMacro.swift

@@ -257,6 +257,11 @@ extension EnumCaseElementListSyntax.Element {
         for index in associatedValue.parameters.indices {
           associatedValue.parameters[index].type.trailingTrivia = ""
           associatedValue.parameters[index].defaultValue = nil
+          if associatedValue.parameters[index].firstName?.tokenKind == .wildcard {
+            associatedValue.parameters[index].colon = nil
+            associatedValue.parameters[index].firstName = nil
+            associatedValue.parameters[index].secondName = nil
+          }
         }
         return "(\(associatedValue.parameters.trimmed))"
       }

Tests/CasePathsMacrosTests/CasePathableMacroTests.swift

@@ -299,6 +299,40 @@ final class CasePathableMacroTests: XCTestCase {
       """
     }
   }
+  
+  func testWildcard() {
+    assertMacro {
+      """
+      @CasePathable enum Foo {
+        case bar(_ int: Int, _ bool: Bool)
+      }
+      """
+    } expansion: {
+      """
+      enum Foo {
+        case bar(_ int: Int, _ bool: Bool)
+
+        struct AllCasePaths {
+          var bar: CasePaths.AnyCasePath<Foo, (Int, Bool)> {
+            CasePaths.AnyCasePath<Foo, (Int, Bool)>(
+              embed: Foo.bar,
+              extract: {
+                guard case let .bar(v0, v1) = $0 else {
+                  return nil
+                }
+                return (v0, v1)
+              }
+            )
+          }
+        }
+        static var allCasePaths: AllCasePaths { AllCasePaths() }
+      }
+
+      extension Foo: CasePaths.CasePathable {
+      }
+      """
+    }
+  }
 
   func testSelf() {
     assertMacro {