Merge remote-tracking branch 'mbp/mutable-js' into ghfix

src/idl_gen_js.cpp

@@ -79,7 +79,7 @@ class JsGenerator : public BaseGenerator {
     for (auto it = parser_.structs_.vec.begin();
          it != parser_.structs_.vec.end(); ++it) {
       auto &struct_def = **it;
-      GenStruct(struct_def, decl_code_ptr, exports_code_ptr);
+      GenStruct(parser_, struct_def, decl_code_ptr, exports_code_ptr);
     }
   }
   void GenNamespaces(std::string *code_ptr, std::string *exports_ptr) {
@@ -361,7 +361,7 @@ static void GenStructBody(const StructDef &struct_def,
 }
 
 // Generate an accessor struct with constructor for a flatbuffers struct.
-void GenStruct(StructDef &struct_def, std::string *code_ptr, std::string *exports_ptr) {
+void GenStruct(const Parser &parser, StructDef &struct_def, std::string *code_ptr, std::string *exports_ptr) {
   if (struct_def.generated) return;
   std::string &code = *code_ptr;
   std::string &exports = *exports_ptr;
@@ -550,6 +550,22 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr, std::string *export
     }
     code += "};\n\n";
 
+    // Adds the mutable scalar value to the output
+    if (IsScalar(field.value.type.base_type) && parser.opts.mutable_buffer) {
+      std::string annotations = "@param {" + GenTypeName(field.value.type, true) + "} value\n";
+      GenDocComment(code_ptr, annotations +
+        "@returns {boolean}");
+
+      code += object_name + ".prototype.mutate_" + field.name + " = function(value) {\n";
+      code += "  var offset = this.bb.__offset(this.bb_pos, " + NumToString(field.value.offset) + ")\n\n";
+      code += "  if (offset === 0) {\n";
+      code += "    return false;\n";
+      code += "  }\n\n";
+      code += "  this.bb.write" + MakeCamel(GenType(field.value.type)) + "(this.bb_pos + offset, value);\n";
+      code += "  return true;\n";
+      code += "}\n\n";
+    }
+
     // Emit vector helpers
     if (field.value.type.base_type == BASE_TYPE_VECTOR) {
       // Emit a length helper

tests/JavaScriptTest.js

@@ -64,7 +64,10 @@ function main() {
 
   fs.writeFileSync('monsterdata_javascript_wire.mon', new Buffer(fbb.asUint8Array()));
 
-  // Test it:
+  // Tests mutation first.  This will verify that we did not trample any other
+  // part of the byte buffer.
+  testMutation(fbb.dataBuffer());
+  
   testBuffer(fbb.dataBuffer());
 
   test64bit();
@@ -74,6 +77,21 @@ function main() {
   console.log('FlatBuffers test: completed successfully');
 }
 
+function testMutation(bb) {
+  var monster = MyGame.Example.Monster.getRootAsMonster(bb);
+
+  monster.mutate_hp(120);
+  assert.strictEqual(monster.hp(), 120);
+
+  monster.mutate_hp(80);
+  assert.strictEqual(monster.hp(), 80);
+
+  var manaRes = monster.mutate_mana(10);
+  assert.strictEqual(manaRes, false);  // Field was NOT present, because default value.
+
+  // TODO: There is not the availability to mutate structs or vectors.
+}
+
 function testBuffer(bb) {
   assert.ok(MyGame.Example.Monster.bufferHasIdentifier(bb));
 

tests/namespace_test/namespace_test1_generated.js

@@ -64,6 +64,21 @@ NamespaceA.NamespaceB.TableInNestedNS.prototype.foo = function() {
   return offset ? this.bb.readInt32(this.bb_pos + offset) : 0;
 };
 
+/**
+ * @param {number} value
+ * @returns {boolean}
+ */
+NamespaceA.NamespaceB.TableInNestedNS.prototype.mutate_foo = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 4)
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeInt32(this.bb_pos + offset, value);
+  return true;
+}
+
 /**
  * @param {flatbuffers.Builder} builder
  */
@@ -121,6 +136,21 @@ NamespaceA.NamespaceB.StructInNestedNS.prototype.a = function() {
   return this.bb.readInt32(this.bb_pos);
 };
 
+/**
+ * @param {number} value
+ * @returns {boolean}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.prototype.mutate_a = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 0)
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeInt32(this.bb_pos + offset, value);
+  return true;
+}
+
 /**
  * @returns {number}
  */
@@ -128,6 +158,21 @@ NamespaceA.NamespaceB.StructInNestedNS.prototype.b = function() {
   return this.bb.readInt32(this.bb_pos + 4);
 };
 
+/**
+ * @param {number} value
+ * @returns {boolean}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.prototype.mutate_b = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 4)
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeInt32(this.bb_pos + offset, value);
+  return true;
+}
+
 /**
  * @param {flatbuffers.Builder} builder
  * @param {number} a

tests/namespace_test/namespace_test2_generated.js

@@ -70,6 +70,21 @@ NamespaceA.TableInFirstNS.prototype.fooEnum = function() {
   return offset ? /** @type {NamespaceA.NamespaceB.EnumInNestedNS} */ (this.bb.readInt8(this.bb_pos + offset)) : NamespaceA.NamespaceB.EnumInNestedNS.A;
 };
 
+/**
+ * @param {NamespaceA.NamespaceB.EnumInNestedNS} value
+ * @returns {boolean}
+ */
+NamespaceA.TableInFirstNS.prototype.mutate_foo_enum = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 6)
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeInt8(this.bb_pos + offset, value);
+  return true;
+}
+
 /**
  * @param {NamespaceA.NamespaceB.StructInNestedNS=} obj
  * @returns {NamespaceA.NamespaceB.StructInNestedNS}