jextract: skip prefix and postfix operators by their modifier

Sources/JExtractSwiftLib/JavaExtractDecider.swift

@@ -71,15 +71,13 @@ public struct JavaExtractDecider: ExtractDecider {
       return false
     }
 
-    // Swift operators have no Java mapping
-    if let fn = decl.as(FunctionDeclSyntax.self) {
-      switch fn.name.tokenKind {
-      case .prefixOperator, .postfixOperator:
-        log.trace("Skip '\(decl.qualifiedNameForDebug)': operators are not supported on Java")
-        return false
-      default:
-        break
-      }
+    // Swift prefix and postfix operators have no Java mapping. A declaration's operator name is
+    // lexed as a binary operator, so only the `prefix` or `postfix` modifier tells them apart.
+    if let fn = decl.as(FunctionDeclSyntax.self),
+      fn.modifiers.contains(where: { $0.name.tokenKind == .keyword(.prefix) || $0.name.tokenKind == .keyword(.postfix) })
+    {
+      log.trace("Skip '\(decl.qualifiedNameForDebug)': operators are not supported on Java")
+      return false
     }
 
     guard let mod = decl.asProtocol((any WithModifiersSyntax).self) else {

Tests/JExtractSwiftTests/JNI/JNIOperatorsTests.swift

@@ -149,4 +149,60 @@ struct JNIOperatorsTests {
       ]
     )
   }
+
+  let prefixAndPostfixSource =
+    """
+    postfix operator ++
+
+    public struct Number {
+      public static prefix func - (value: Number) -> Number {
+        value
+      }
+
+      public static postfix func ++ (value: Number) -> Number {
+        value
+      }
+
+      public static func + (left: Number, right: Number) -> Number {
+        Number()
+      }
+    }
+    """
+
+  @Test
+  func prefixAndPostfixOperators_areSkipped_javaBindings() throws {
+    try assertOutput(
+      input: prefixAndPostfixSource,
+      .jni,
+      .java,
+      expectedChunks: [
+        """
+        private static native long $plus(long left, long right);
+        """
+      ],
+      notExpectedChunks: [
+        "prefix func",
+        "postfix func",
+      ]
+    )
+  }
+
+  @Test
+  func prefixAndPostfixOperators_areSkipped_swiftThunks() throws {
+    try assertOutput(
+      input: prefixAndPostfixSource,
+      .jni,
+      .swift,
+      detectChunkByInitialLines: 1,
+      expectedChunks: [
+        """
+        @_cdecl("Java_com_example_swift_Number__00024plus__JJ")
+        """
+      ],
+      notExpectedChunks: [
+        "minus",
+        "++",
+      ]
+    )
+  }
 }