From a40e6cd8586944c4e3801f46972784a79407abbe Mon Sep 17 00:00:00 2001
From: achingbrain <alex@achingbrain.net>
Date: Thu, 11 Aug 2022 08:19:14 +0100
Subject: [PATCH] feat: define default types

Proto3 language guide [states](https://developers.google.com/protocol-buffers/docs/proto3#default):

> When a message is parsed, if the encoded message does not contain a particular singular element, the corresponding field in the parsed object is set to the default value for
that field.

When decoding objects, create an object with all non-optional fields set to the default values, then overwrite them during decoding.

Refs #43
---
 .../protons-benchmark/src/protons/bench.ts    |  21 +--
 packages/protons-runtime/src/index.ts         |   6 +-
 packages/protons/src/index.ts                 |  88 +++++++++-
 packages/protons/test/fixtures/basic.proto    |   2 +-
 packages/protons/test/fixtures/basic.ts       |   4 +-
 packages/protons/test/fixtures/circuit.ts     |  14 +-
 packages/protons/test/fixtures/daemon.ts      | 158 +++++++-----------
 packages/protons/test/fixtures/dht.ts         |  31 +---
 packages/protons/test/fixtures/noise.ts       |   6 +-
 packages/protons/test/fixtures/peer.ts        |  34 ++--
 packages/protons/test/fixtures/test.ts        |  15 +-
 packages/protons/test/index.spec.ts           |  12 ++
 12 files changed, 212 insertions(+), 179 deletions(-)

diff --git a/packages/protons-benchmark/src/protons/bench.ts b/packages/protons-benchmark/src/protons/bench.ts
index efcdf84..e5f8110 100644
--- a/packages/protons-benchmark/src/protons/bench.ts
+++ b/packages/protons-benchmark/src/protons/bench.ts
@@ -28,7 +28,7 @@ export namespace Foo {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Foo = {}
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -84,7 +84,7 @@ export namespace Bar {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Bar = {}
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -159,7 +159,9 @@ export namespace Yo {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Yo = {
+          lol: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -168,7 +170,6 @@ export namespace Yo {
 
           switch (tag >>> 3) {
             case 1:
-              obj.lol = obj.lol ?? []
               obj.lol.push(FOO.codec().decode(reader))
               break
             default:
@@ -177,12 +178,6 @@ export namespace Yo {
           }
         }
 
-        obj.lol = obj.lol ?? []
-
-        if (obj.lol == null) {
-          throw new Error('Protocol error: value for required field "lol" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -230,7 +225,9 @@ export namespace Lol {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Lol = {
+          b: null
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -311,7 +308,7 @@ export namespace Test {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Test = {}
 
         const end = length == null ? reader.len : reader.pos + length
 
diff --git a/packages/protons-runtime/src/index.ts b/packages/protons-runtime/src/index.ts
index 095bf20..54ac86b 100644
--- a/packages/protons-runtime/src/index.ts
+++ b/packages/protons-runtime/src/index.ts
@@ -180,12 +180,12 @@ export interface Reader {
   double: () => number
 
   /**
-   * Reads a sequence of bytes preceeded by its length as a varint
+   * Reads a sequence of bytes preceded by its length as a varint
    */
-  bytes: () => number
+  bytes: () => Uint8Array
 
   /**
-   * Reads a string preceeded by its byte length as a varint
+   * Reads a string preceded by its byte length as a varint
    */
   string: () => string
 
diff --git a/packages/protons/src/index.ts b/packages/protons/src/index.ts
index 2b03b25..4a5c8a3 100644
--- a/packages/protons/src/index.ts
+++ b/packages/protons/src/index.ts
@@ -73,6 +73,25 @@ const decoderGenerators: Record<string, () => string> = {
   uint64: () => 'reader.uint64()'
 }
 
+const defaultValueGenerators: Record<string, () => string> = {
+  bool: () => 'false',
+  bytes: () => 'new Uint8Array(0)',
+  double: () => '0',
+  // enumeration: () => `writer.double(${val})`,
+  fixed32: () => '0',
+  fixed64: () => '0n',
+  float: () => '0',
+  int32: () => '0',
+  int64: () => '0n',
+  sfixed32: () => '0',
+  sfixed64: () => '0n',
+  sint32: () => '0',
+  sint64: () => '0n',
+  string: () => "''",
+  uint32: () => '0',
+  uint64: () => '0n'
+}
+
 function findTypeName (typeName: string, classDef: MessageDef, moduleDef: ModuleDef): string {
   if (types[typeName] != null) {
     return types[typeName]
@@ -117,6 +136,65 @@ function findDef (typeName: string, classDef: MessageDef, moduleDef: ModuleDef):
   throw new Error(`Could not resolve type name "${typeName}"`)
 }
 
+function createDefaultObject (fields: Record<string, FieldDef>, messageDef: MessageDef, moduleDef: ModuleDef): string {
+  const output = Object.entries(fields)
+    .map(([name, fieldDef]) => {
+      if (fieldDef.repeated) {
+        return `${name}: []`
+      }
+
+      if (fieldDef.optional) {
+        return ''
+      }
+
+      const type: string = fieldDef.type
+      let defaultValue
+
+      if (defaultValueGenerators[type] != null) {
+        defaultValue = defaultValueGenerators[type]()
+      } else {
+        const def = findDef(fieldDef.type, messageDef, moduleDef)
+
+        if (isEnumDef(def)) {
+          // select lowest-value enum - should be 0 but it's not guaranteed
+          const val = Object.entries(def.values)
+            .sort((a, b) => {
+              if (a[1] < b[1]) {
+                return 1
+              }
+
+              if (a[1] > b[1]) {
+                return -1
+              }
+
+              return 0
+            })
+            .pop()
+
+          if (val == null) {
+            throw new Error(`Could not find default enum value for ${def.fullName}`)
+          }
+
+          defaultValue = `${def.name}.${val[0]}`
+        } else {
+          defaultValue = 'null'
+        }
+      }
+
+      return `${name}: ${defaultValue}`
+    })
+    .filter(Boolean)
+    .join(',\n          ')
+
+  if (output !== '') {
+    return `
+          ${output}
+        `
+  }
+
+  return ''
+}
+
 const encoders: Record<string, string> = {
   bool: 'bool',
   bytes: 'bytes',
@@ -259,7 +337,7 @@ export interface ${messageDef.name} {
     const ensureArrayProps = Object.entries(fields)
       .map(([name, fieldDef]) => {
         // make sure repeated fields have an array if not set
-        if (fieldDef.rule === 'repeated') {
+        if (fieldDef.optional && fieldDef.rule === 'repeated') {
           return `        obj.${name} = obj.${name} ?? []`
         }
 
@@ -269,7 +347,7 @@ export interface ${messageDef.name} {
     const ensureRequiredFields = Object.entries(fields)
       .map(([name, fieldDef]) => {
         // make sure required fields are set
-        if (!fieldDef.optional) {
+        if (!fieldDef.optional && !fieldDef.repeated) {
           return `
         if (obj.${name} == null) {
           throw new Error('Protocol error: value for required field "${name}" was not found in protobuf')
@@ -331,7 +409,7 @@ ${Object.entries(fields)
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: ${messageDef.name} = {${createDefaultObject(fields, messageDef, moduleDef)}}
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -360,8 +438,10 @@ ${Object.entries(fields)
                 }
 
                 return `case ${fieldDef.id}:${fieldDef.rule === 'repeated'
+? `${fieldDef.optional
 ? `
-              obj.${name} = obj.${name} ?? []
+              obj.${name} = obj.${name} ?? []`
+: ''}
               obj.${name}.push(${decoderGenerators[type] == null ? `${codec}.decode(reader${type === 'message' ? ', reader.uint32()' : ''})` : decoderGenerators[type]()})`
 : `
               obj.${name} = ${decoderGenerators[type] == null ? `${codec}.decode(reader${type === 'message' ? ', reader.uint32()' : ''})` : decoderGenerators[type]()}`}
diff --git a/packages/protons/test/fixtures/basic.proto b/packages/protons/test/fixtures/basic.proto
index 55882d4..83fbc41 100644
--- a/packages/protons/test/fixtures/basic.proto
+++ b/packages/protons/test/fixtures/basic.proto
@@ -2,5 +2,5 @@ syntax = "proto3";
 
 message Basic {
   optional string foo = 1;
-  required int32 num = 2;
+  int32 num = 2;
 }
diff --git a/packages/protons/test/fixtures/basic.ts b/packages/protons/test/fixtures/basic.ts
index 0950495..d13e6ce 100644
--- a/packages/protons/test/fixtures/basic.ts
+++ b/packages/protons/test/fixtures/basic.ts
@@ -36,7 +36,9 @@ export namespace Basic {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Basic = {
+          num: 0
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
diff --git a/packages/protons/test/fixtures/circuit.ts b/packages/protons/test/fixtures/circuit.ts
index 44b0127..f3a651e 100644
--- a/packages/protons/test/fixtures/circuit.ts
+++ b/packages/protons/test/fixtures/circuit.ts
@@ -112,7 +112,10 @@ export namespace CircuitRelay {
             writer.ldelim()
           }
         }, (reader, length) => {
-          const obj: any = {}
+          const obj: Peer = {
+            id: new Uint8Array(0),
+            addrs: []
+          }
 
           const end = length == null ? reader.len : reader.pos + length
 
@@ -124,7 +127,6 @@ export namespace CircuitRelay {
                 obj.id = reader.bytes()
                 break
               case 2:
-                obj.addrs = obj.addrs ?? []
                 obj.addrs.push(reader.bytes())
                 break
               default:
@@ -133,16 +135,10 @@ export namespace CircuitRelay {
             }
           }
 
-          obj.addrs = obj.addrs ?? []
-
           if (obj.id == null) {
             throw new Error('Protocol error: value for required field "id" was not found in protobuf')
           }
 
-          if (obj.addrs == null) {
-            throw new Error('Protocol error: value for required field "addrs" was not found in protobuf')
-          }
-
           return obj
         })
       }
@@ -192,7 +188,7 @@ export namespace CircuitRelay {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: CircuitRelay = {}
 
         const end = length == null ? reader.len : reader.pos + length
 
diff --git a/packages/protons/test/fixtures/daemon.ts b/packages/protons/test/fixtures/daemon.ts
index e2f0627..c66a93d 100644
--- a/packages/protons/test/fixtures/daemon.ts
+++ b/packages/protons/test/fixtures/daemon.ts
@@ -110,7 +110,9 @@ export namespace Request {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Request = {
+          type: Type.IDENTIFY
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -258,7 +260,10 @@ export namespace Response {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Response = {
+          type: Type.OK,
+          peers: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -282,7 +287,6 @@ export namespace Response {
               obj.dht = DHTResponse.codec().decode(reader, reader.uint32())
               break
             case 6:
-              obj.peers = obj.peers ?? []
               obj.peers.push(PeerInfo.codec().decode(reader, reader.uint32()))
               break
             case 7:
@@ -297,16 +301,10 @@ export namespace Response {
           }
         }
 
-        obj.peers = obj.peers ?? []
-
         if (obj.type == null) {
           throw new Error('Protocol error: value for required field "type" was not found in protobuf')
         }
 
-        if (obj.peers == null) {
-          throw new Error('Protocol error: value for required field "peers" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -358,7 +356,10 @@ export namespace IdentifyResponse {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: IdentifyResponse = {
+          id: new Uint8Array(0),
+          addrs: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -370,7 +371,6 @@ export namespace IdentifyResponse {
               obj.id = reader.bytes()
               break
             case 2:
-              obj.addrs = obj.addrs ?? []
               obj.addrs.push(reader.bytes())
               break
             default:
@@ -379,16 +379,10 @@ export namespace IdentifyResponse {
           }
         }
 
-        obj.addrs = obj.addrs ?? []
-
         if (obj.id == null) {
           throw new Error('Protocol error: value for required field "id" was not found in protobuf')
         }
 
-        if (obj.addrs == null) {
-          throw new Error('Protocol error: value for required field "addrs" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -446,7 +440,10 @@ export namespace ConnectRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: ConnectRequest = {
+          peer: new Uint8Array(0),
+          addrs: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -458,7 +455,6 @@ export namespace ConnectRequest {
               obj.peer = reader.bytes()
               break
             case 2:
-              obj.addrs = obj.addrs ?? []
               obj.addrs.push(reader.bytes())
               break
             case 3:
@@ -470,16 +466,10 @@ export namespace ConnectRequest {
           }
         }
 
-        obj.addrs = obj.addrs ?? []
-
         if (obj.peer == null) {
           throw new Error('Protocol error: value for required field "peer" was not found in protobuf')
         }
 
-        if (obj.addrs == null) {
-          throw new Error('Protocol error: value for required field "addrs" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -537,7 +527,10 @@ export namespace StreamOpenRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: StreamOpenRequest = {
+          peer: new Uint8Array(0),
+          proto: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -549,7 +542,6 @@ export namespace StreamOpenRequest {
               obj.peer = reader.bytes()
               break
             case 2:
-              obj.proto = obj.proto ?? []
               obj.proto.push(reader.string())
               break
             case 3:
@@ -561,16 +553,10 @@ export namespace StreamOpenRequest {
           }
         }
 
-        obj.proto = obj.proto ?? []
-
         if (obj.peer == null) {
           throw new Error('Protocol error: value for required field "peer" was not found in protobuf')
         }
 
-        if (obj.proto == null) {
-          throw new Error('Protocol error: value for required field "proto" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -622,7 +608,10 @@ export namespace StreamHandlerRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: StreamHandlerRequest = {
+          addr: new Uint8Array(0),
+          proto: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -634,7 +623,6 @@ export namespace StreamHandlerRequest {
               obj.addr = reader.bytes()
               break
             case 2:
-              obj.proto = obj.proto ?? []
               obj.proto.push(reader.string())
               break
             default:
@@ -643,16 +631,10 @@ export namespace StreamHandlerRequest {
           }
         }
 
-        obj.proto = obj.proto ?? []
-
         if (obj.addr == null) {
           throw new Error('Protocol error: value for required field "addr" was not found in protobuf')
         }
 
-        if (obj.proto == null) {
-          throw new Error('Protocol error: value for required field "proto" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -694,7 +676,9 @@ export namespace ErrorResponse {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: ErrorResponse = {
+          msg: ''
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -772,7 +756,11 @@ export namespace StreamInfo {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: StreamInfo = {
+          peer: new Uint8Array(0),
+          addr: new Uint8Array(0),
+          proto: ''
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -914,7 +902,9 @@ export namespace DHTRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: DHTRequest = {
+          type: Type.FIND_PEER
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1024,7 +1014,9 @@ export namespace DHTResponse {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: DHTResponse = {
+          type: Type.BEGIN
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1102,7 +1094,10 @@ export namespace PeerInfo {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PeerInfo = {
+          id: new Uint8Array(0),
+          addrs: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1114,7 +1109,6 @@ export namespace PeerInfo {
               obj.id = reader.bytes()
               break
             case 2:
-              obj.addrs = obj.addrs ?? []
               obj.addrs.push(reader.bytes())
               break
             default:
@@ -1123,16 +1117,10 @@ export namespace PeerInfo {
           }
         }
 
-        obj.addrs = obj.addrs ?? []
-
         if (obj.id == null) {
           throw new Error('Protocol error: value for required field "id" was not found in protobuf')
         }
 
-        if (obj.addrs == null) {
-          throw new Error('Protocol error: value for required field "addrs" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -1210,7 +1198,9 @@ export namespace ConnManagerRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: ConnManagerRequest = {
+          type: Type.TAG_PEER
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1281,7 +1271,9 @@ export namespace DisconnectRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: DisconnectRequest = {
+          peer: new Uint8Array(0)
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1375,7 +1367,9 @@ export namespace PSRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PSRequest = {
+          type: Type.GET_TOPICS
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1475,7 +1469,9 @@ export namespace PSMessage {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PSMessage = {
+          topicIDs: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1493,7 +1489,6 @@ export namespace PSMessage {
               obj.seqno = reader.bytes()
               break
             case 4:
-              obj.topicIDs = obj.topicIDs ?? []
               obj.topicIDs.push(reader.string())
               break
             case 5:
@@ -1508,12 +1503,6 @@ export namespace PSMessage {
           }
         }
 
-        obj.topicIDs = obj.topicIDs ?? []
-
-        if (obj.topicIDs == null) {
-          throw new Error('Protocol error: value for required field "topicIDs" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -1567,7 +1556,10 @@ export namespace PSResponse {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PSResponse = {
+          topics: [],
+          peerIDs: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1576,11 +1568,9 @@ export namespace PSResponse {
 
           switch (tag >>> 3) {
             case 1:
-              obj.topics = obj.topics ?? []
               obj.topics.push(reader.string())
               break
             case 2:
-              obj.peerIDs = obj.peerIDs ?? []
               obj.peerIDs.push(reader.bytes())
               break
             default:
@@ -1589,17 +1579,6 @@ export namespace PSResponse {
           }
         }
 
-        obj.topics = obj.topics ?? []
-        obj.peerIDs = obj.peerIDs ?? []
-
-        if (obj.topics == null) {
-          throw new Error('Protocol error: value for required field "topics" was not found in protobuf')
-        }
-
-        if (obj.peerIDs == null) {
-          throw new Error('Protocol error: value for required field "peerIDs" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -1673,7 +1652,10 @@ export namespace PeerstoreRequest {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PeerstoreRequest = {
+          type: Type.GET_PROTOCOLS,
+          protos: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1688,7 +1670,6 @@ export namespace PeerstoreRequest {
               obj.id = reader.bytes()
               break
             case 3:
-              obj.protos = obj.protos ?? []
               obj.protos.push(reader.string())
               break
             default:
@@ -1697,16 +1678,10 @@ export namespace PeerstoreRequest {
           }
         }
 
-        obj.protos = obj.protos ?? []
-
         if (obj.type == null) {
           throw new Error('Protocol error: value for required field "type" was not found in protobuf')
         }
 
-        if (obj.protos == null) {
-          throw new Error('Protocol error: value for required field "protos" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -1756,7 +1731,9 @@ export namespace PeerstoreResponse {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: PeerstoreResponse = {
+          protos: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -1768,7 +1745,6 @@ export namespace PeerstoreResponse {
               obj.peer = PeerInfo.codec().decode(reader, reader.uint32())
               break
             case 2:
-              obj.protos = obj.protos ?? []
               obj.protos.push(reader.string())
               break
             default:
@@ -1777,12 +1753,6 @@ export namespace PeerstoreResponse {
           }
         }
 
-        obj.protos = obj.protos ?? []
-
-        if (obj.protos == null) {
-          throw new Error('Protocol error: value for required field "protos" was not found in protobuf')
-        }
-
         return obj
       })
     }
diff --git a/packages/protons/test/fixtures/dht.ts b/packages/protons/test/fixtures/dht.ts
index fc278a9..0ea8566 100644
--- a/packages/protons/test/fixtures/dht.ts
+++ b/packages/protons/test/fixtures/dht.ts
@@ -52,7 +52,7 @@ export namespace Record {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Record = {}
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -190,7 +190,9 @@ export namespace Message {
             writer.ldelim()
           }
         }, (reader, length) => {
-          const obj: any = {}
+          const obj: Peer = {
+            addrs: []
+          }
 
           const end = length == null ? reader.len : reader.pos + length
 
@@ -202,7 +204,6 @@ export namespace Message {
                 obj.id = reader.bytes()
                 break
               case 2:
-                obj.addrs = obj.addrs ?? []
                 obj.addrs.push(reader.bytes())
                 break
               case 3:
@@ -214,12 +215,6 @@ export namespace Message {
             }
           }
 
-          obj.addrs = obj.addrs ?? []
-
-          if (obj.addrs == null) {
-            throw new Error('Protocol error: value for required field "addrs" was not found in protobuf')
-          }
-
           return obj
         })
       }
@@ -287,7 +282,10 @@ export namespace Message {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Message = {
+          closerPeers: [],
+          providerPeers: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -308,11 +306,9 @@ export namespace Message {
               obj.record = reader.bytes()
               break
             case 8:
-              obj.closerPeers = obj.closerPeers ?? []
               obj.closerPeers.push(Message.Peer.codec().decode(reader, reader.uint32()))
               break
             case 9:
-              obj.providerPeers = obj.providerPeers ?? []
               obj.providerPeers.push(Message.Peer.codec().decode(reader, reader.uint32()))
               break
             default:
@@ -321,17 +317,6 @@ export namespace Message {
           }
         }
 
-        obj.closerPeers = obj.closerPeers ?? []
-        obj.providerPeers = obj.providerPeers ?? []
-
-        if (obj.closerPeers == null) {
-          throw new Error('Protocol error: value for required field "closerPeers" was not found in protobuf')
-        }
-
-        if (obj.providerPeers == null) {
-          throw new Error('Protocol error: value for required field "providerPeers" was not found in protobuf')
-        }
-
         return obj
       })
     }
diff --git a/packages/protons/test/fixtures/noise.ts b/packages/protons/test/fixtures/noise.ts
index 0bdada6..154febf 100644
--- a/packages/protons/test/fixtures/noise.ts
+++ b/packages/protons/test/fixtures/noise.ts
@@ -47,7 +47,11 @@ export namespace pb {
             writer.ldelim()
           }
         }, (reader, length) => {
-          const obj: any = {}
+          const obj: NoiseHandshakePayload = {
+            identityKey: new Uint8Array(0),
+            identitySig: new Uint8Array(0),
+            data: new Uint8Array(0)
+          }
 
           const end = length == null ? reader.len : reader.pos + length
 
diff --git a/packages/protons/test/fixtures/peer.ts b/packages/protons/test/fixtures/peer.ts
index 68bd477..893e1ce 100644
--- a/packages/protons/test/fixtures/peer.ts
+++ b/packages/protons/test/fixtures/peer.ts
@@ -64,7 +64,11 @@ export namespace Peer {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Peer = {
+          addresses: [],
+          protocols: [],
+          metadata: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -73,15 +77,12 @@ export namespace Peer {
 
           switch (tag >>> 3) {
             case 1:
-              obj.addresses = obj.addresses ?? []
               obj.addresses.push(Address.codec().decode(reader, reader.uint32()))
               break
             case 2:
-              obj.protocols = obj.protocols ?? []
               obj.protocols.push(reader.string())
               break
             case 3:
-              obj.metadata = obj.metadata ?? []
               obj.metadata.push(Metadata.codec().decode(reader, reader.uint32()))
               break
             case 4:
@@ -96,22 +97,6 @@ export namespace Peer {
           }
         }
 
-        obj.addresses = obj.addresses ?? []
-        obj.protocols = obj.protocols ?? []
-        obj.metadata = obj.metadata ?? []
-
-        if (obj.addresses == null) {
-          throw new Error('Protocol error: value for required field "addresses" was not found in protobuf')
-        }
-
-        if (obj.protocols == null) {
-          throw new Error('Protocol error: value for required field "protocols" was not found in protobuf')
-        }
-
-        if (obj.metadata == null) {
-          throw new Error('Protocol error: value for required field "metadata" was not found in protobuf')
-        }
-
         return obj
       })
     }
@@ -159,7 +144,9 @@ export namespace Address {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Address = {
+          multiaddr: new Uint8Array(0)
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -232,7 +219,10 @@ export namespace Metadata {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: Metadata = {
+          key: '',
+          value: new Uint8Array(0)
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
diff --git a/packages/protons/test/fixtures/test.ts b/packages/protons/test/fixtures/test.ts
index eea1650..f830ad3 100644
--- a/packages/protons/test/fixtures/test.ts
+++ b/packages/protons/test/fixtures/test.ts
@@ -45,7 +45,9 @@ export namespace SubMessage {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: SubMessage = {
+          foo: ''
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -211,7 +213,9 @@ export namespace AllTheTypes {
           writer.ldelim()
         }
       }, (reader, length) => {
-        const obj: any = {}
+        const obj: AllTheTypes = {
+          field14: []
+        }
 
         const end = length == null ? reader.len : reader.pos + length
 
@@ -259,7 +263,6 @@ export namespace AllTheTypes {
               obj.field13 = SubMessage.codec().decode(reader, reader.uint32())
               break
             case 14:
-              obj.field14 = obj.field14 ?? []
               obj.field14.push(reader.string())
               break
             case 15:
@@ -280,12 +283,6 @@ export namespace AllTheTypes {
           }
         }
 
-        obj.field14 = obj.field14 ?? []
-
-        if (obj.field14 == null) {
-          throw new Error('Protocol error: value for required field "field14" was not found in protobuf')
-        }
-
         return obj
       })
     }
diff --git a/packages/protons/test/index.spec.ts b/packages/protons/test/index.spec.ts
index 060c8d6..a97825b 100644
--- a/packages/protons/test/index.spec.ts
+++ b/packages/protons/test/index.spec.ts
@@ -180,4 +180,16 @@ describe('encode', () => {
     expect(CircuitRelay.decode(encoded)).to.deep.equal(message)
     expect(CircuitRelay.decode(pbufJsBuf)).to.deep.equal(message)
   })
+
+  it('supports optional fields', () => {
+    const obj: Basic = {
+      num: 5
+    }
+
+    const encoded = Basic.encode(obj)
+    const decoded = Basic.decode(encoded)
+
+    // foo is optional
+    expect(decoded).to.not.have.property('foo')
+  })
 })