feat: extensions (#808)

* feat: extensions

* docs: outputExtensions=true

README.markdown

@@ -461,7 +461,7 @@ Generated code will be placed in the Gradle build directory.
 
 - With `--ts_proto_opt=useJsonWireFormat=true`, the generated code will reflect the JSON representation of Protobuf messages.
 
-  Requires `onlyTypes=true`. Implies `useDate=string` and `stringEnums=true`. This option is to generate types that can be directly used with marshalling/unmarshalling Protobuf messages serialized as JSON.  
+  Requires `onlyTypes=true`. Implies `useDate=string` and `stringEnums=true`. This option is to generate types that can be directly used with marshalling/unmarshalling Protobuf messages serialized as JSON.
   You may also want to set `useOptionals=all`, as gRPC gateways are not required to send default value for scalar values.
 
 - With `--ts_proto_opt=useNumericEnumForJson=true`, the JSON converter (`toJSON`) will encode enum values as int, rather than a string literal.
@@ -502,6 +502,11 @@ Generated code will be placed in the Gradle build directory.
 
   by default this is enabled which would generate a type of `Box_Element_Image_Alignment`. By disabling this option the type that is generated would be `BoxElementImageAlignment`.
 
+- With `--ts_proto_opt=outputExtensions=true`, the generated code will include proto2 extensions
+
+  Extension encode/decode methods are compliant with the `outputEncodeMethods` option, and if `unknownFields=true`,
+  the `setExtension` and `getExtension` methods will be created for extendable messages, also compliant with `outputEncodeMethods` (setExtension = encode, getExtension = decode).
+
 ### NestJS Support
 
 We have a great way of working together with [nestjs](https://docs.nestjs.com/microservices/grpc). `ts-proto` generates `interfaces` and `decorators` for you controller, client. For more information see the [nestjs readme](NESTJS.markdown).

integration/extensions/extensions-test.ts

@@ -0,0 +1,103 @@
+import { Extendable, Nested, packed, repeated, bytes, string, long, fixed, enumField, group, Enum } from './test';
+import * as Long from 'long';
+
+describe('extensions-test', () => {
+	it('works with namespaced extensions', () => {
+		const test: Extendable = {
+			field: 'hello'
+		};
+
+		const extensionData = [
+			{
+				field: 'a'
+			},
+			{
+				field: 'b'
+			}
+		];
+
+		Extendable.setExtension(test, Nested.message, extensionData);
+
+		const encoded = Extendable.encode(test).finish();
+		const result = Extendable.decode(encoded);
+
+		expect(result).toEqual(test);
+
+		const extension = Extendable.getExtension(result, Nested.message);
+
+		expect(extension).toEqual(extensionData);
+
+		const unsetExtension = Extendable.getExtension(result, packed);
+
+		expect(unsetExtension).toEqual(undefined);
+	});
+
+	it('works with repeated fields', () => {
+		const test: Extendable = {
+			field: 'repeated',
+
+			_unknownFields: {
+				[(6 << 3) | 2]: [Buffer.from([1, 1]), Buffer.from([1, 1])],
+				[(6 << 3) | 0]: [Buffer.from([2]), Buffer.from([3]), Buffer.from([5])]
+			}
+		};
+
+		const extensionData = [1, 2, 3, 4, 5];
+
+		Extendable.setExtension(test, packed, extensionData);
+
+		const encoded = Extendable.encode(test).finish();
+		const result = Extendable.decode(encoded);
+
+		expect(result).toEqual(test);
+
+		const extension = Extendable.getExtension(result, packed);
+
+		expect(extension).toEqual(extensionData);
+
+		expect(Extendable.getExtension(result, repeated)).toEqual([1, 1, 2, 3, 5]);
+
+		const unsetExtension = Extendable.getExtension(result, Nested.message);
+
+		expect(unsetExtension).toEqual(undefined);
+	});
+
+	it('works with various field types', () => {
+		const test: Extendable = {
+			field: 'various'
+		};
+
+		const bytesExtensionData = Buffer.from([2, 3, 5, 7, 11]);
+		const stringExtensionData = "this is a string";
+		const longExtensionData = new Long(0x89ABCDEF, 0x01234567, false);
+		const fixedExtensionData = new Long(0x01234567, 0x89ABCDEF, true);
+		const enumExtensionData = Enum.ENUM_ONE;
+		const groupExtensionData = {
+			name: 'this is',
+			value: 'a group'
+		};
+
+		Extendable.setExtension(test, bytes, bytesExtensionData);
+		Extendable.setExtension(test, string, stringExtensionData);
+		Extendable.setExtension(test, long, longExtensionData);
+		Extendable.setExtension(test, fixed, fixedExtensionData);
+		Extendable.setExtension(test, enumField, enumExtensionData);
+		Extendable.setExtension(test, group, groupExtensionData);
+
+		const encoded = Extendable.encode(test).finish();
+		const result = Extendable.decode(encoded);
+
+		expect(result).toEqual(test);
+
+		expect( Extendable.getExtension(result, bytes) ).toEqual(bytesExtensionData);
+		expect( Extendable.getExtension(result, string) ).toEqual(stringExtensionData);
+		expect( Extendable.getExtension(result, long) ).toEqual(longExtensionData);
+		expect( Extendable.getExtension(result, fixed) ).toEqual(fixedExtensionData);
+		expect( Extendable.getExtension(result, enumField) ).toEqual(enumExtensionData);
+		expect( Extendable.getExtension(result, group) ).toEqual(groupExtensionData);
+
+		const unsetExtension = Extendable.getExtension(result, Nested.message);
+
+		expect(unsetExtension).toEqual(undefined);
+	});
+});

integration/extensions/parameters.txt

@@ -0,0 +1 @@
+outputExtensions=true,forceLong=long,unknownFields=true,initializeFieldsAsUndefined=false,useOptionals=all

integration/extensions/test.proto

@@ -0,0 +1,35 @@
+syntax = "proto2";
+
+message Extendable{
+  required string field = 1;
+
+  extensions 4 to max;
+}
+
+message Nested{
+  required string field = 1;
+
+  extend Extendable{
+    repeated Nested message = 4;
+  }
+}
+
+enum Enum{
+  ENUM_UNRECOGNIZED = 0;
+  ENUM_ONE = 1;
+  ENUM_TWO = 2;
+}
+
+extend Extendable{
+  repeated int32 packed = 5 [packed = true];
+  repeated int32 repeated = 6;
+  optional bytes bytes = 7;
+  optional string string = 8;
+  optional int64 long = 9;
+  optional fixed64 fixed = 10;
+  optional Enum enum_field = 11;
+  optional group Group = 12 {
+    optional string name = 1;
+    optional string value = 2;
+  }
+}