feat: add codecs for ilp fulfillment packets

packages/ilp-packet/index.ts

@@ -13,7 +13,8 @@ enum Type {
   TYPE_ILQP_BY_SOURCE_RESPONSE = 5,
   TYPE_ILQP_BY_DESTINATION_REQUEST = 6,
   TYPE_ILQP_BY_DESTINATION_RESPONSE = 7,
-  TYPE_ILP_ERROR = 8
+  TYPE_ILP_ERROR = 8,
+  TYPE_ILP_FULFILLMENT = 9
 }
 
 const serializeEnvelope = (type: number, contents: Buffer) => {
@@ -456,6 +457,40 @@ const deserializeIlpError = (binary: Buffer): IlpError => {
   }
 }
 
+interface IlpFulfillment {
+  data: string
+}
+
+const serializeIlpFulfillment = (json: IlpFulfillment) => {
+  const writer = new Writer()
+
+  // data
+  writer.writeVarOctetString(Buffer.from(json.data || '', 'base64'))
+
+  // extensibility
+  writer.writeUInt8(0)
+
+  return serializeEnvelope(Type.TYPE_ILP_FULFILLMENT, writer.getBuffer())
+}
+
+const deserializeIlpFulfillment = (binary: Buffer): IlpFulfillment => {
+  const { type, contents } = deserializeEnvelope(binary)
+
+  if (type !== Type.TYPE_ILP_FULFILLMENT) {
+    throw new Error('Packet has incorrect type')
+  }
+
+  const reader = Reader.from(contents)
+
+  const data = base64url(reader.readVarOctetString())
+
+  // Ignore remaining bytes for extensibility
+
+  return {
+    data
+  }
+}
+
 const serializeIlpPacket = (obj: IlpPacket) => {
   switch (obj.type) {
     case Type.TYPE_ILP_PAYMENT: return serializeIlpPayment(obj.data)
@@ -466,12 +501,14 @@ const serializeIlpPacket = (obj: IlpPacket) => {
     case Type.TYPE_ILQP_BY_DESTINATION_REQUEST: return serializeIlqpByDestinationRequest(obj.data)
     case Type.TYPE_ILQP_BY_DESTINATION_RESPONSE: return serializeIlqpByDestinationResponse(obj.data)
     case Type.TYPE_ILP_ERROR: return serializeIlpError(obj.data)
+    case Type.TYPE_ILP_FULFILLMENT: return serializeIlpFulfillment(obj.data)
     default: throw new Error('Object has invalid type')
   }
 }
 
 const deserializeIlpPacket = (binary: Buffer) => {
-  let packet, typeString
+  let packet
+  let typeString
   switch (binary[0]) {
     case Type.TYPE_ILP_PAYMENT:
       packet = deserializeIlpPayment(binary)
@@ -505,6 +542,10 @@ const deserializeIlpPacket = (binary: Buffer) => {
       packet = deserializeIlpError(binary)
       typeString = 'ilp_error'
       break
+    case Type.TYPE_ILP_FULFILLMENT:
+      packet = deserializeIlpFulfillment(binary)
+      typeString = 'ilp_fulfillment'
+      break
     default:
       throw new Error('Packet has invalid type')
   }
@@ -533,6 +574,8 @@ module.exports = {
   deserializeIlqpByDestinationResponse,
   serializeIlpError,
   deserializeIlpError,
+  serializeIlpFulfillment,
+  deserializeIlpFulfillment,
   serializeIlpPacket,
   deserializeIlpPacket
 }

packages/ilp-packet/test/data/ilp_fulfillment/valid/example01.json

@@ -0,0 +1,7 @@
+{
+  "name": "example 1",
+  "binary": "09020000",
+  "json": {
+    "data": ""
+  }
+}

packages/ilp-packet/test/data/ilp_fulfillment/valid/example02.json

@@ -0,0 +1,7 @@
+{
+  "name": "example 2",
+  "binary": "09050365965900",
+  "json": {
+    "data": "ZZZZ"
+  }
+}

packages/ilp-packet/test/parser.spec.ts

@@ -236,7 +236,7 @@ describe('Parser', function () {
   })
 
   describe('serializeIlpError', function () {
-    describe('correctly serializes valid ilqp by destination responses', function () {
+    describe('correctly serializes valid ilp errors', function () {
       const validTests = loadTests({ type: 'ilp_error' })
 
       for (let test of validTests) {
@@ -254,7 +254,7 @@ describe('Parser', function () {
   })
 
   describe('deserializeIlpError', function () {
-    describe('correctly parses valid ilqp by destination responses', function () {
+    describe('correctly parses valid ilp errors', function () {
       const validTests = loadTests({ type: 'ilp_error' })
 
       for (let test of validTests) {
@@ -271,6 +271,38 @@ describe('Parser', function () {
     })
   })
 
+  describe('serializeIlpFulfillment', function () {
+    describe('correctly serializes valid ilp fulfillments', function () {
+      const validTests = loadTests({ type: 'ilp_fulfillment' })
+
+      for (let test of validTests) {
+        it(test.name, function () {
+          const json = test.json
+
+          const serialized = Parser.serializeIlpFulfillment(json)
+
+          assert.deepEqual(serialized.toString('hex'), test.binary)
+        })
+      }
+    })
+  })
+
+  describe('deserializeIlpFulfillment', function () {
+    describe('correctly parses valid ilp fulfillments', function () {
+      const validTests = loadTests({ type: 'ilp_fulfillment' })
+
+      for (let test of validTests) {
+        it(test.name, function () {
+          const binary = new Buffer(test.binary, 'hex')
+
+          const parsed = Parser.deserializeIlpFulfillment(binary)
+
+          assert.deepEqual(parsed, test.json)
+        })
+      }
+    })
+  })
+
   describe('deserializeIlpPacket', function () {
     describe('correctly parses valid ilp packets', function () {
       testPackets('ilp_payment', Parser.Type.TYPE_ILP_PAYMENT)