Preventing assignment to readonly properties of function.

jsdevel · jsdevel · commit a453fdc80f8b · 2015-04-27T02:31:50.000-07:00
diff --git a/lib/nodeJavaBridge.js b/lib/nodeJavaBridge.js
@@ -179,6 +179,15 @@ java.onJvmCreated = function() {
 var MODIFIER_PUBLIC = 1;
 var MODIFIER_STATIC = 8;
 
+function isWritable(obj, prop) {
+  if (!prop || !obj) {
+    return false;
+  }
+
+  // If the property has no descriptor, or wasn't explicitly marked as not writable,
+  // assume it is.
+  return (Object.getOwnPropertyDescriptor(obj, prop) || {}).writable !== false;
+}
 
 java.import = function(name) {
   var clazz = java.findClassSync(name); // TODO: change to Class.forName when classloader issue is resolved.
@@ -223,12 +232,20 @@ java.import = function(name) {
     if (((modifiers & MODIFIER_PUBLIC) === MODIFIER_PUBLIC)
       && ((modifiers & MODIFIER_STATIC) === MODIFIER_STATIC)) {
       var methodName = SyncCall(methods[i], 'getName')();
-      result[methodName + syncSuffix] = java.callStaticMethodSync.bind(java, name, methodName);
-      if (typeof asyncSuffix === 'string') {
-        result[methodName + asyncSuffix] = java.callStaticMethod.bind(java, name, methodName);
+      var syncName = methodName + syncSuffix;
+      var asyncName = methodName + asyncSuffix;
+      var promiseName = methodName + promiseSuffix;
+
+      if (isWritable(result, syncName)) {
+        result[syncName] = java.callStaticMethodSync.bind(java, name, methodName);
       }
-      if (promisify) {
-        result[methodName + promiseSuffix] = promisify(java.callStaticMethod.bind(java, name, methodName));
+
+      if (typeof asyncSuffix === 'string' && isWritable(result, asyncName)) {
+        result[asyncName] = java.callStaticMethod.bind(java, name, methodName);
+      }
+
+      if (promisify && isWritable(result, promiseName)) {
+        result[promiseName] = promisify(java.callStaticMethod.bind(java, name, methodName));
       }
     }
   }
diff --git a/test/Test.class b/test/Test.class
diff --git a/test/Test.java b/test/Test.java
@@ -171,4 +171,7 @@ public static enum StaticEnum {
   public static String varArgsSignature(Long... args) { return "Long..."; }
   public static String varArgsSignature(Number... args) { return "Number..."; }
   public static String varArgsSignature(String... args) { return "String..."; }
+  // Test readonly properties on functions that throw errors in certain versions of
+  // node.
+  public static void name() {}
 }

Original file line number	Diff line number	Diff line change
`@@ -171,4 +171,7 @@ public static enum StaticEnum {`
`171`	`171`	`public static String varArgsSignature(Long... args) { return "Long..."; }`
`172`	`172`	`public static String varArgsSignature(Number... args) { return "Number..."; }`
`173`	`173`	`public static String varArgsSignature(String... args) { return "String..."; }`
	`174`	`+ // Test readonly properties on functions that throw errors in certain versions of`
	`175`	`+ // node.`
	`176`	`+ public static void name() {}`
`174`	`177`	`}`