From 44108e58911d7265e24db64758640f6b63eaed2d Mon Sep 17 00:00:00 2001
From: Abhinav Gupta <abg@uber.com>
Date: Mon, 30 Aug 2021 12:17:18 -0700
Subject: [PATCH 1/3] Back to development

---
 CHANGELOG.md                                                  | 4 ++++
 gen/internal/tests/collision/collision.go                     | 2 +-
 gen/internal/tests/constants/constants.go                     | 2 +-
 gen/internal/tests/containers/containers.go                   | 2 +-
 .../enum-text-marshal-strict/enum-text-marshal-strict.go      | 2 +-
 gen/internal/tests/enum_conflict/enum_conflict.go             | 2 +-
 gen/internal/tests/enums/enums.go                             | 2 +-
 gen/internal/tests/exceptions/exceptions.go                   | 2 +-
 gen/internal/tests/hyphenated-file/hyphenated-file.go         | 2 +-
 gen/internal/tests/hyphenated_file/hyphenated_file.go         | 2 +-
 gen/internal/tests/non_hyphenated/non_hyphenated.go           | 2 +-
 gen/internal/tests/nozap/nozap.go                             | 2 +-
 gen/internal/tests/other_constants/other_constants.go         | 2 +-
 gen/internal/tests/services/services.go                       | 2 +-
 gen/internal/tests/set_to_slice/set_to_slice.go               | 2 +-
 gen/internal/tests/structs/structs.go                         | 2 +-
 gen/internal/tests/typedefs/typedefs.go                       | 2 +-
 gen/internal/tests/unions/unions.go                           | 2 +-
 gen/internal/tests/uuid_conflict/uuid_conflict.go             | 2 +-
 internal/envelope/exception/exception.go                      | 2 +-
 plugin/api/api.go                                             | 2 +-
 version/version.go                                            | 2 +-
 22 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c184192..a45a4cf5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+- No changes yet.
+
 ## [1.29.0] - 2021-08-30
 This release includes support for (de)serializing Thrift structs directly
 to/from IO streams without converting them to the intermediate `wire.Value`
@@ -418,6 +421,7 @@ this release.
 ### Added
 - Initial release.
 
+[Unreleased]: https://github.com/thriftrw/thriftrw-go/compare/v1.29.0...HEAD
 [1.29.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.28.0...v1.29.0
 [1.28.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.27.0...v1.28.0
 [1.27.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.26.0...v1.27.0
diff --git a/gen/internal/tests/collision/collision.go b/gen/internal/tests/collision/collision.go
index 54a23120..3a43a248 100644
--- a/gen/internal/tests/collision/collision.go
+++ b/gen/internal/tests/collision/collision.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package collision
diff --git a/gen/internal/tests/constants/constants.go b/gen/internal/tests/constants/constants.go
index 9d4a634f..2b7cd480 100644
--- a/gen/internal/tests/constants/constants.go
+++ b/gen/internal/tests/constants/constants.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package constants
diff --git a/gen/internal/tests/containers/containers.go b/gen/internal/tests/containers/containers.go
index bdb8e2a0..fd0a59c1 100644
--- a/gen/internal/tests/containers/containers.go
+++ b/gen/internal/tests/containers/containers.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package containers
diff --git a/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go b/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
index cbcc1fe1..dd74b4e8 100644
--- a/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
+++ b/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package enum_text_marshal_strict
diff --git a/gen/internal/tests/enum_conflict/enum_conflict.go b/gen/internal/tests/enum_conflict/enum_conflict.go
index 8e82e4b6..6893f7e3 100644
--- a/gen/internal/tests/enum_conflict/enum_conflict.go
+++ b/gen/internal/tests/enum_conflict/enum_conflict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package enum_conflict
diff --git a/gen/internal/tests/enums/enums.go b/gen/internal/tests/enums/enums.go
index 140934f5..ad430e5c 100644
--- a/gen/internal/tests/enums/enums.go
+++ b/gen/internal/tests/enums/enums.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package enums
diff --git a/gen/internal/tests/exceptions/exceptions.go b/gen/internal/tests/exceptions/exceptions.go
index 9708bb50..c24fe897 100644
--- a/gen/internal/tests/exceptions/exceptions.go
+++ b/gen/internal/tests/exceptions/exceptions.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package exceptions
diff --git a/gen/internal/tests/hyphenated-file/hyphenated-file.go b/gen/internal/tests/hyphenated-file/hyphenated-file.go
index 8990b73f..f17d00ae 100644
--- a/gen/internal/tests/hyphenated-file/hyphenated-file.go
+++ b/gen/internal/tests/hyphenated-file/hyphenated-file.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package hyphenated_file
diff --git a/gen/internal/tests/hyphenated_file/hyphenated_file.go b/gen/internal/tests/hyphenated_file/hyphenated_file.go
index 3796dbc6..d9f2c8ae 100644
--- a/gen/internal/tests/hyphenated_file/hyphenated_file.go
+++ b/gen/internal/tests/hyphenated_file/hyphenated_file.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package hyphenated_file
diff --git a/gen/internal/tests/non_hyphenated/non_hyphenated.go b/gen/internal/tests/non_hyphenated/non_hyphenated.go
index 357d8944..26fcb921 100644
--- a/gen/internal/tests/non_hyphenated/non_hyphenated.go
+++ b/gen/internal/tests/non_hyphenated/non_hyphenated.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package non_hyphenated
diff --git a/gen/internal/tests/nozap/nozap.go b/gen/internal/tests/nozap/nozap.go
index 1a83c063..69ddbe3e 100644
--- a/gen/internal/tests/nozap/nozap.go
+++ b/gen/internal/tests/nozap/nozap.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package nozap
diff --git a/gen/internal/tests/other_constants/other_constants.go b/gen/internal/tests/other_constants/other_constants.go
index 896f4381..5d682a65 100644
--- a/gen/internal/tests/other_constants/other_constants.go
+++ b/gen/internal/tests/other_constants/other_constants.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package other_constants
diff --git a/gen/internal/tests/services/services.go b/gen/internal/tests/services/services.go
index 47acbf84..2bfa5e4b 100644
--- a/gen/internal/tests/services/services.go
+++ b/gen/internal/tests/services/services.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package services
diff --git a/gen/internal/tests/set_to_slice/set_to_slice.go b/gen/internal/tests/set_to_slice/set_to_slice.go
index 62a3b72e..d2faf01a 100644
--- a/gen/internal/tests/set_to_slice/set_to_slice.go
+++ b/gen/internal/tests/set_to_slice/set_to_slice.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package set_to_slice
diff --git a/gen/internal/tests/structs/structs.go b/gen/internal/tests/structs/structs.go
index 56beee27..6bb8d868 100644
--- a/gen/internal/tests/structs/structs.go
+++ b/gen/internal/tests/structs/structs.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package structs
diff --git a/gen/internal/tests/typedefs/typedefs.go b/gen/internal/tests/typedefs/typedefs.go
index a3891307..7977f904 100644
--- a/gen/internal/tests/typedefs/typedefs.go
+++ b/gen/internal/tests/typedefs/typedefs.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package typedefs
diff --git a/gen/internal/tests/unions/unions.go b/gen/internal/tests/unions/unions.go
index 6a3cba64..7c96efce 100644
--- a/gen/internal/tests/unions/unions.go
+++ b/gen/internal/tests/unions/unions.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package unions
diff --git a/gen/internal/tests/uuid_conflict/uuid_conflict.go b/gen/internal/tests/uuid_conflict/uuid_conflict.go
index 58165a1e..df3e2e0e 100644
--- a/gen/internal/tests/uuid_conflict/uuid_conflict.go
+++ b/gen/internal/tests/uuid_conflict/uuid_conflict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 package uuid_conflict
diff --git a/internal/envelope/exception/exception.go b/internal/envelope/exception/exception.go
index fb1cf44c..f67e31c3 100644
--- a/internal/envelope/exception/exception.go
+++ b/internal/envelope/exception/exception.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 // Copyright (c) 2021 Uber Technologies, Inc.
diff --git a/plugin/api/api.go b/plugin/api/api.go
index 9f748bc4..623727a7 100644
--- a/plugin/api/api.go
+++ b/plugin/api/api.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.29.0. DO NOT EDIT.
+// Code generated by thriftrw v1.30.0. DO NOT EDIT.
 // @generated
 
 // Copyright (c) 2021 Uber Technologies, Inc.
diff --git a/version/version.go b/version/version.go
index 7d2c8306..4a223c5b 100644
--- a/version/version.go
+++ b/version/version.go
@@ -21,4 +21,4 @@
 package version
 
 // Version is the current ThriftRW version.
-const Version = "1.29.0"
+const Version = "1.30.0"

From 4cb2e58ed04a4f5171ba3acbb0d81fc7a6363e3c Mon Sep 17 00:00:00 2001
From: Wit Riewrangboonya <wit@uber.com>
Date: Tue, 31 Aug 2021 16:28:46 -0700
Subject: [PATCH 2/3] streaming: Handle nil items in containers (#541)

`nil` items should be handled gracefully similar to the Wire-based
representation.

Ref #183

Co-authored-by: Abhinav Gupta <abg@uber.com>
---
 CHANGELOG.md                                  |  3 +-
 gen/container_test.go                         | 29 ++++--
 gen/internal/tests/containers/containers.go   | 97 ++++++++++++++-----
 gen/internal/tests/services/services.go       |  7 +-
 .../tests/set_to_slice/set_to_slice.go        | 10 +-
 gen/internal/tests/structs/structs.go         | 12 ++-
 gen/internal/tests/typedefs/typedefs.go       | 43 ++++++--
 gen/internal/tests/unions/unions.go           | 12 ++-
 gen/list.go                                   | 13 ++-
 gen/map.go                                    | 33 ++++++-
 gen/set.go                                    | 10 +-
 plugin/api/api.go                             | 29 ++++--
 12 files changed, 231 insertions(+), 67 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a45a4cf5..6ecd4506 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-- No changes yet.
+### Fixed
+- Streaming encodes now handle `nil` items properly in containers.
 
 ## [1.29.0] - 2021-08-30
 This release includes support for (de)serializing Thrift structs directly
diff --git a/gen/container_test.go b/gen/container_test.go
index 2bbff729..c065c893 100644
--- a/gen/container_test.go
+++ b/gen/container_test.go
@@ -21,12 +21,14 @@
 package gen
 
 import (
+	"bytes"
 	"encoding/json"
 	"testing"
 
 	tc "go.uber.org/thriftrw/gen/internal/tests/containers"
 	te "go.uber.org/thriftrw/gen/internal/tests/enums"
 	ts "go.uber.org/thriftrw/gen/internal/tests/structs"
+	"go.uber.org/thriftrw/protocol/binary"
 	"go.uber.org/thriftrw/wire"
 
 	"github.com/stretchr/testify/assert"
@@ -1278,7 +1280,7 @@ func TestContainerValidate(t *testing.T) {
 					{4, 5, 6},
 				},
 			},
-			wantError: "invalid [2]: value is nil",
+			wantError: "invalid list '[][]byte', index [2]: value is nil",
 		},
 		{
 			desc: "nil second element of array",
@@ -1289,14 +1291,14 @@ func TestContainerValidate(t *testing.T) {
 					{StartPoint: &ts.Point{X: 5, Y: 6}, EndPoint: &ts.Point{X: 7, Y: 8}},
 				},
 			},
-			wantError: "invalid [1]: value is nil",
+			wantError: "invalid list '[]*Edge', index [1]: value is nil",
 		},
 		{
 			desc: "nil set item",
 			value: &tc.ContainersOfContainers{
 				SetOfLists: [][]string{{}, nil},
 			},
-			wantError: "invalid set item: value is nil",
+			wantError: "invalid set '[]string': contains nil value",
 		},
 		{
 			desc: "nil map key",
@@ -1309,7 +1311,7 @@ func TestContainerValidate(t *testing.T) {
 					{Key: nil, Value: "foo"},
 				},
 			},
-			wantError: "invalid map key: value is nil",
+			wantError: "invalid map '[]struct{Key []byte; Value string}': key is nil",
 		},
 		{
 			desc: "nil map value",
@@ -1319,12 +1321,12 @@ func TestContainerValidate(t *testing.T) {
 					"foo":   nil,
 				},
 			},
-			wantError: "invalid [foo]: value is nil",
+			wantError: "invalid map 'map[string][]byte', key [foo]: value is nil",
 		},
 	}
 
 	for _, tt := range tests {
-		t.Run(tt.desc, func(t *testing.T) {
+		t.Run(tt.desc+"/wire", func(t *testing.T) {
 			value, err := tt.value.ToWire()
 			if err == nil {
 				err = wire.EvaluateValue(value) // lazy error
@@ -1334,6 +1336,21 @@ func TestContainerValidate(t *testing.T) {
 				assert.Equal(t, tt.wantError, err.Error())
 			}
 		})
+
+		t.Run(tt.desc+"/streaming", func(t *testing.T) {
+			stt, ok := tt.value.(streamingThriftType)
+			require.True(t, ok)
+
+			var buf bytes.Buffer
+			sw := binary.Default.Writer(&buf)
+			defer func() {
+				assert.NoError(t, sw.Close())
+			}()
+
+			err := stt.Encode(sw)
+			require.Error(t, err)
+			assert.Equal(t, tt.wantError, err.Error())
+		})
 	}
 }
 
diff --git a/gen/internal/tests/containers/containers.go b/gen/internal/tests/containers/containers.go
index fd0a59c1..e08d5441 100644
--- a/gen/internal/tests/containers/containers.go
+++ b/gen/internal/tests/containers/containers.go
@@ -72,7 +72,7 @@ type _List_List_I32_ValueList [][]int32
 func (v _List_List_I32_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[][]int32', index [%v]: value is nil", i)
 		}
 		w, err := wire.NewValueList(_List_I32_ValueList(x)), error(nil)
 		if err != nil {
@@ -127,7 +127,7 @@ type _List_Set_I32_mapType_ValueList []map[int32]struct{}
 func (v _List_Set_I32_mapType_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]map[int32]struct{}', index [%v]: value is nil", i)
 		}
 		w, err := wire.NewValueSet(_Set_I32_mapType_ValueList(x)), error(nil)
 		if err != nil {
@@ -191,7 +191,7 @@ type _List_Map_I32_I32_ValueList []map[int32]int32
 func (v _List_Map_I32_I32_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]map[int32]int32', index [%v]: value is nil", i)
 		}
 		w, err := wire.NewValueMap(_Map_I32_I32_MapItemList(x)), error(nil)
 		if err != nil {
@@ -246,7 +246,7 @@ type _Set_Set_String_mapType_sliceType_ValueList []map[string]struct{}
 func (v _Set_Set_String_mapType_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set 'map[string]struct{}': contains nil value")
 		}
 		w, err := wire.NewValueSet(_Set_String_mapType_ValueList(x)), error(nil)
 		if err != nil {
@@ -301,7 +301,7 @@ type _Set_List_String_sliceType_ValueList [][]string
 func (v _Set_List_String_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set '[]string': contains nil value")
 		}
 		w, err := wire.NewValueList(_List_String_ValueList(x)), error(nil)
 		if err != nil {
@@ -365,7 +365,7 @@ type _Set_Map_String_String_sliceType_ValueList []map[string]string
 func (v _Set_Map_String_String_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set 'map[string]string': contains nil value")
 		}
 		w, err := wire.NewValueMap(_Map_String_String_MapItemList(x)), error(nil)
 		if err != nil {
@@ -434,7 +434,7 @@ func (m _Map_Map_String_I32_I64_MapItemList) ForEach(f func(wire.MapItem) error)
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key map[string]int32; Value int64}': key is nil")
 		}
 		kw, err := wire.NewValueMap(_Map_String_I32_MapItemList(k)), error(nil)
 		if err != nil {
@@ -503,10 +503,10 @@ func (m _Map_List_I32_Set_I64_mapType_MapItemList) ForEach(f func(wire.MapItem)
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key []int32; Value map[int64]struct{}}': key is nil")
 		}
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map '[]struct{Key []int32; Value map[int64]struct{}}', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueList(_List_I32_ValueList(k)), error(nil)
 		if err != nil {
@@ -575,10 +575,10 @@ func (m _Map_Set_I32_mapType_List_Double_MapItemList) ForEach(f func(wire.MapIte
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key map[int32]struct{}; Value []float64}': key is nil")
 		}
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map '[]struct{Key map[int32]struct{}; Value []float64}', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueSet(_Set_I32_mapType_ValueList(k)), error(nil)
 		if err != nil {
@@ -1255,7 +1255,10 @@ func _List_List_I32_Encode(val [][]int32, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[][]int32', index [%v]: value is nil", i)
+		}
 		if err := _List_I32_Encode(v, sw); err != nil {
 			return err
 		}
@@ -1293,7 +1296,10 @@ func _List_Set_I32_mapType_Encode(val []map[int32]struct{}, sw stream.Writer) er
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]map[int32]struct{}', index [%v]: value is nil", i)
+		}
 		if err := _Set_I32_mapType_Encode(v, sw); err != nil {
 			return err
 		}
@@ -1334,7 +1340,10 @@ func _List_Map_I32_I32_Encode(val []map[int32]int32, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]map[int32]int32', index [%v]: value is nil", i)
+		}
 		if err := _Map_I32_I32_Encode(v, sw); err != nil {
 			return err
 		}
@@ -1374,6 +1383,9 @@ func _Set_Set_String_mapType_sliceType_Encode(val []map[string]struct{}, sw stre
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set 'map[string]struct{}': contains nil value")
+		}
 
 		if err := _Set_String_mapType_Encode(v, sw); err != nil {
 			return err
@@ -1412,6 +1424,9 @@ func _Set_List_String_sliceType_Encode(val [][]string, sw stream.Writer) error {
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set '[]string': contains nil value")
+		}
 
 		if err := _List_String_Encode(v, sw); err != nil {
 			return err
@@ -1455,6 +1470,9 @@ func _Set_Map_String_String_sliceType_Encode(val []map[string]string, sw stream.
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set 'map[string]string': contains nil value")
+		}
 
 		if err := _Map_String_String_Encode(v, sw); err != nil {
 			return err
@@ -1502,10 +1520,14 @@ func _Map_Map_String_I32_I64_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key map[string]int32; Value int64}': key is nil")
+		}
 		if err := _Map_String_I32_Encode(key, sw); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := sw.WriteInt64(value); err != nil {
 			return err
 		}
@@ -1550,10 +1572,17 @@ func _Map_List_I32_Set_I64_mapType_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key []int32; Value map[int64]struct{}}': key is nil")
+		}
+		if value == nil {
+			return fmt.Errorf("invalid map '[]struct{Key []int32; Value map[int64]struct{}}', key [%v]: value is nil", key)
+		}
 		if err := _List_I32_Encode(key, sw); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := _Set_I64_mapType_Encode(value, sw); err != nil {
 			return err
 		}
@@ -1596,10 +1625,17 @@ func _Map_Set_I32_mapType_List_Double_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key map[int32]struct{}; Value []float64}': key is nil")
+		}
+		if value == nil {
+			return fmt.Errorf("invalid map '[]struct{Key map[int32]struct{}; Value []float64}', key [%v]: value is nil", key)
+		}
 		if err := _Set_I32_mapType_Encode(key, sw); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := _List_Double_Encode(value, sw); err != nil {
 			return err
 		}
@@ -4660,7 +4696,7 @@ type _List_UUID_ValueList []*typedefs.UUID
 func (v _List_UUID_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*typedefs.UUID', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -4863,7 +4899,10 @@ func _List_UUID_Encode(val []*typedefs.UUID, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*typedefs.UUID', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
@@ -5613,7 +5652,7 @@ func (m _Map_Binary_String_MapItemList) ForEach(f func(wire.MapItem) error) erro
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key []byte; Value string}': key is nil")
 		}
 		kw, err := wire.NewValueBinary(k), error(nil)
 		if err != nil {
@@ -5651,7 +5690,7 @@ type _Map_String_Binary_MapItemList map[string][]byte
 func (m _Map_String_Binary_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[string][]byte', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueString(k), error(nil)
 		if err != nil {
@@ -5852,10 +5891,14 @@ func _Map_Binary_String_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key []byte; Value string}': key is nil")
+		}
 		if err := sw.WriteBinary(key); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := sw.WriteString(value); err != nil {
 			return err
 		}
@@ -5876,6 +5919,9 @@ func _Map_String_Binary_Encode(val map[string][]byte, sw stream.Writer) error {
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[string][]byte', key [%v]: value is nil", k)
+		}
 		if err := sw.WriteString(k); err != nil {
 			return err
 		}
@@ -6257,7 +6303,7 @@ type _List_Binary_ValueList [][]byte
 func (v _List_Binary_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[][]byte', index [%v]: value is nil", i)
 		}
 		w, err := wire.NewValueBinary(x), error(nil)
 		if err != nil {
@@ -6675,7 +6721,10 @@ func _List_Binary_Encode(val [][]byte, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[][]byte', index [%v]: value is nil", i)
+		}
 		if err := sw.WriteBinary(v); err != nil {
 			return err
 		}
diff --git a/gen/internal/tests/services/services.go b/gen/internal/tests/services/services.go
index 2bfa5e4b..f9a9cbca 100644
--- a/gen/internal/tests/services/services.go
+++ b/gen/internal/tests/services/services.go
@@ -2621,7 +2621,7 @@ type _List_ArbitraryValue_ValueList []*unions.ArbitraryValue
 func (v _List_ArbitraryValue_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*unions.ArbitraryValue', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -2781,7 +2781,10 @@ func _List_ArbitraryValue_Encode(val []*unions.ArbitraryValue, sw stream.Writer)
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*unions.ArbitraryValue', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
diff --git a/gen/internal/tests/set_to_slice/set_to_slice.go b/gen/internal/tests/set_to_slice/set_to_slice.go
index d2faf01a..cbb89919 100644
--- a/gen/internal/tests/set_to_slice/set_to_slice.go
+++ b/gen/internal/tests/set_to_slice/set_to_slice.go
@@ -167,7 +167,7 @@ type _Set_Foo_sliceType_ValueList []*Foo
 func (v _Set_Foo_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set '*Foo': contains nil value")
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -196,7 +196,7 @@ type _Set_Set_String_sliceType_sliceType_ValueList [][]string
 func (v _Set_Set_String_sliceType_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set '[]string': contains nil value")
 		}
 		w, err := wire.NewValueSet(_Set_String_sliceType_ValueList(x)), error(nil)
 		if err != nil {
@@ -628,6 +628,9 @@ func _Set_Foo_sliceType_Encode(val []*Foo, sw stream.Writer) error {
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set '*Foo': contains nil value")
+		}
 
 		if err := v.Encode(sw); err != nil {
 			return err
@@ -648,6 +651,9 @@ func _Set_Set_String_sliceType_sliceType_Encode(val [][]string, sw stream.Writer
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set '[]string': contains nil value")
+		}
 
 		if err := _Set_String_sliceType_Encode(v, sw); err != nil {
 			return err
diff --git a/gen/internal/tests/structs/structs.go b/gen/internal/tests/structs/structs.go
index 6bb8d868..9757c58f 100644
--- a/gen/internal/tests/structs/structs.go
+++ b/gen/internal/tests/structs/structs.go
@@ -3069,7 +3069,7 @@ type _List_Edge_ValueList []*Edge
 func (v _List_Edge_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*Edge', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -3196,7 +3196,10 @@ func _List_Edge_Encode(val []*Edge, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*Edge', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
@@ -7871,7 +7874,7 @@ type _Map_String_User_MapItemList map[string]*User
 func (m _Map_String_User_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[string]*User', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueString(k), error(nil)
 		if err != nil {
@@ -7916,6 +7919,9 @@ func _Map_String_User_Encode(val map[string]*User, sw stream.Writer) error {
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[string]*User', key [%v]: value is nil", k)
+		}
 		if err := sw.WriteString(k); err != nil {
 			return err
 		}
diff --git a/gen/internal/tests/typedefs/typedefs.go b/gen/internal/tests/typedefs/typedefs.go
index 7977f904..42faf8e0 100644
--- a/gen/internal/tests/typedefs/typedefs.go
+++ b/gen/internal/tests/typedefs/typedefs.go
@@ -23,7 +23,7 @@ type _Set_Binary_sliceType_ValueList [][]byte
 func (v _Set_Binary_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set '[]byte': contains nil value")
 		}
 		w, err := wire.NewValueBinary(x), error(nil)
 		if err != nil {
@@ -59,6 +59,9 @@ func _Set_Binary_sliceType_Encode(val [][]byte, sw stream.Writer) error {
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set '[]byte': contains nil value")
+		}
 
 		if err := sw.WriteBinary(v); err != nil {
 			return err
@@ -464,10 +467,10 @@ func (m _Map_Edge_Edge_MapItemList) ForEach(f func(wire.MapItem) error) error {
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Edge; Value *structs.Edge}': key is nil")
 		}
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Edge; Value *structs.Edge}', key [%v]: value is nil", k)
 		}
 		kw, err := k.ToWire()
 		if err != nil {
@@ -516,10 +519,17 @@ func _Map_Edge_Edge_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Edge; Value *structs.Edge}': key is nil")
+		}
+		if value == nil {
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Edge; Value *structs.Edge}', key [%v]: value is nil", key)
+		}
 		if err := key.Encode(sw); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := value.Encode(sw); err != nil {
 			return err
 		}
@@ -1074,7 +1084,7 @@ type _List_Event_ValueList []*Event
 func (v _List_Event_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*Event', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -1108,7 +1118,10 @@ func _List_Event_Encode(val []*Event, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*Event', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
@@ -1254,7 +1267,7 @@ type _Set_Frame_sliceType_ValueList []*structs.Frame
 func (v _Set_Frame_sliceType_ValueList) ForEach(f func(wire.Value) error) error {
 	for _, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid set item: value is nil")
+			return fmt.Errorf("invalid set '*structs.Frame': contains nil value")
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -1290,6 +1303,9 @@ func _Set_Frame_sliceType_Encode(val []*structs.Frame, sw stream.Writer) error {
 	}
 
 	for _, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid set '*structs.Frame': contains nil value")
+		}
 
 		if err := v.Encode(sw); err != nil {
 			return err
@@ -1599,10 +1615,10 @@ func (m _Map_Point_Point_MapItemList) ForEach(f func(wire.MapItem) error) error
 		k := i.Key
 		v := i.Value
 		if k == nil {
-			return fmt.Errorf("invalid map key: value is nil")
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Point; Value *structs.Point}': key is nil")
 		}
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Point; Value *structs.Point}', key [%v]: value is nil", k)
 		}
 		kw, err := k.ToWire()
 		if err != nil {
@@ -1651,10 +1667,17 @@ func _Map_Point_Point_Encode(val []struct {
 
 	for _, v := range val {
 		key := v.Key
+		value := v.Value
+
+		if key == nil {
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Point; Value *structs.Point}': key is nil")
+		}
+		if value == nil {
+			return fmt.Errorf("invalid map '[]struct{Key *structs.Point; Value *structs.Point}', key [%v]: value is nil", key)
+		}
 		if err := key.Encode(sw); err != nil {
 			return err
 		}
-		value := v.Value
 		if err := value.Encode(sw); err != nil {
 			return err
 		}
diff --git a/gen/internal/tests/unions/unions.go b/gen/internal/tests/unions/unions.go
index 7c96efce..f3fd9acb 100644
--- a/gen/internal/tests/unions/unions.go
+++ b/gen/internal/tests/unions/unions.go
@@ -37,7 +37,7 @@ type _List_ArbitraryValue_ValueList []*ArbitraryValue
 func (v _List_ArbitraryValue_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*ArbitraryValue', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -66,7 +66,7 @@ type _Map_String_ArbitraryValue_MapItemList map[string]*ArbitraryValue
 func (m _Map_String_ArbitraryValue_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[string]*ArbitraryValue', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueString(k), error(nil)
 		if err != nil {
@@ -326,7 +326,10 @@ func _List_ArbitraryValue_Encode(val []*ArbitraryValue, sw stream.Writer) error
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*ArbitraryValue', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
@@ -346,6 +349,9 @@ func _Map_String_ArbitraryValue_Encode(val map[string]*ArbitraryValue, sw stream
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[string]*ArbitraryValue', key [%v]: value is nil", k)
+		}
 		if err := sw.WriteString(k); err != nil {
 			return err
 		}
diff --git a/gen/list.go b/gen/list.go
index fcd07cb6..62feb4d3 100644
--- a/gen/list.go
+++ b/gen/list.go
@@ -60,7 +60,7 @@ func (l *listGenerator) ValueList(g Generator, spec *compile.ListSpec) (string,
 				<- else ->
 				for <$i>, <$x> := range <$v> {
 					if <$x> == nil {
-						return <import "fmt">.Errorf("invalid [%v]: value is nil", <$i>)
+						return <import "fmt">.Errorf("invalid list '<typeReference .Spec>', index [%v]: value is nil", <$i>)
 					}
 				<- end>
 					<$w>, err := <toWire .Spec.ValueSpec $x>
@@ -156,11 +156,12 @@ func (l *listGenerator) Encoder(g Generator, spec *compile.ListSpec) (string, er
 		<$listType := typeReference .Spec>
 		<$sw := newVar "sw">
 		<$lh := newVar "lh">
+		<$i := newVar "i">
 		<$o := newVar "o">
 		<$k := newVar "k">
 		<$v := newVar "v">
 		<$val := newVar "val">
-		func <.Name>(<$val> <$listType>, <$sw> <$stream>.Writer) error {	
+		func <.Name>(<$val> <$listType>, <$sw> <$stream>.Writer) error {
 			<$vt := typeCode .Spec.ValueSpec>
 			<$lh> := <$stream>.ListHeader{
 				Type: <$vt>,
@@ -170,7 +171,15 @@ func (l *listGenerator) Encoder(g Generator, spec *compile.ListSpec) (string, er
 				return err
 			}
 
+			<if isPrimitiveType .Spec.ValueSpec ->
 			for _, <$v> := range <$val> {
+			<- else ->
+			for <$i>, <$v> := range <$val> {
+				if <$v> == nil {
+					return <import "fmt">.Errorf("invalid list '<typeReference .Spec>', index [%v]: value is nil", <$i>)
+				}
+			<end ->
+
 				if err := <encode .Spec.ValueSpec $v $sw>; err != nil {
 					return err
 				}
diff --git a/gen/map.go b/gen/map.go
index 51d7a42f..f261a341 100644
--- a/gen/map.go
+++ b/gen/map.go
@@ -70,12 +70,12 @@ func (m *mapGenerator) ItemList(g Generator, spec *compile.MapSpec) (string, err
 				<end>
 						<- if not (isPrimitiveType .Spec.KeySpec) ->
 							if <$k> == nil {
-								return <import "fmt">.Errorf("invalid map key: value is nil")
+								return <import "fmt">.Errorf("invalid map '<typeReference .Spec>': key is nil")
 							}
 						<end ->
 						<- if not (isPrimitiveType .Spec.ValueSpec) ->
 							if <$v> == nil {
-								return <import "fmt">.Errorf("invalid [%v]: value is nil", <$k>)
+								return <import "fmt">.Errorf("invalid map '<typeReference .Spec>', key [%v]: value is nil", <$k>)
 							}
 						<end ->
 
@@ -203,7 +203,7 @@ func (m *mapGenerator) Encoder(g Generator, spec *compile.MapSpec) (string, erro
 		<$value := newVar "value">
 		func <.Name>(<$val> <$mapType>, <$sw> <$stream>.Writer) error {
 			<$kt := typeCode .Spec.KeySpec>
-			<$vt := typeCode .Spec.ValueSpec>	
+			<$vt := typeCode .Spec.ValueSpec>
 			<$mh> := <$stream>.MapHeader{
 				KeyType: <$kt>,
 				ValueType: <$vt>,
@@ -215,20 +215,43 @@ func (m *mapGenerator) Encoder(g Generator, spec *compile.MapSpec) (string, erro
 
 			<if isHashable .Spec.KeySpec>
 				for <$k>, <$v> := range <$val> {
+					<- if not (isPrimitiveType .Spec.KeySpec) ->
+					if <$k> == nil {
+						return <import "fmt">.Errorf("invalid map '<typeReference .Spec>': key is nil")
+					}
+					<end ->
+					<- if not (isPrimitiveType .Spec.ValueSpec) ->
+					if <$v> == nil {
+						return <import "fmt">.Errorf("invalid map '<typeReference .Spec>', key [%v]: value is nil", <$k>)
+					}
+					<end ->
+
 					if err := <encode .Spec.KeySpec $k $sw>; err != nil {
 						return err
 					}
 					if err := <encode .Spec.ValueSpec $v $sw>; err != nil {
 						return err
 					}
-				}		
+				}
 			<else>
 				for _, <$v> := range <$val> {
 					<$key> := <printf "%s.Key" $v>
+					<$value> := <printf "%s.Value" $v>
+
+					<if not (isPrimitiveType .Spec.KeySpec) ->
+					if <$key> == nil {
+						return <import "fmt">.Errorf("invalid map '<typeReference .Spec>': key is nil")
+					}
+					<end ->
+					<- if not (isPrimitiveType .Spec.ValueSpec) ->
+					if <$value> == nil {
+						return <import "fmt">.Errorf("invalid map '<typeReference .Spec>', key [%v]: value is nil", <$key>)
+					}
+					<end ->
+
 					if err := <encode .Spec.KeySpec $key $sw>; err != nil {
 						return err
 					}
-					<$value> := <printf "%s.Value" $v>
 					if err := <encode .Spec.ValueSpec $value $sw>; err != nil {
 						return err
 					}
diff --git a/gen/set.go b/gen/set.go
index abce3c50..fc760460 100644
--- a/gen/set.go
+++ b/gen/set.go
@@ -61,7 +61,7 @@ func (s *setGenerator) ValueList(g Generator, spec *compile.SetSpec) (string, er
 				<- end ->
 						<if not (isPrimitiveType .Spec.ValueSpec)>
 							if <$x> == nil {
-								return <import "fmt">.Errorf("invalid set item: value is nil")
+								return <import "fmt">.Errorf("invalid set '<typeReference .Spec.ValueSpec>': contains nil value")
 							}
 						<end ->
 
@@ -155,7 +155,7 @@ func (s *setGenerator) Encoder(g Generator, spec *compile.SetSpec) (string, erro
 		<$k := newVar "k">
 		<$v := newVar "v">
 		<$val := newVar "val">
-		func <.Name>(<$val> <$setType>, <$sw> <$stream>.Writer) error {	
+		func <.Name>(<$val> <$setType>, <$sw> <$stream>.Writer) error {
 			<$vt := typeCode .Spec.ValueSpec>
 			<$sh> := <$stream>.SetHeader{
 				Type: <$vt>,
@@ -171,6 +171,12 @@ func (s *setGenerator) Encoder(g Generator, spec *compile.SetSpec) (string, erro
 			<else>
 				for _, <$v> := range <$val> {
 			<end>
+					<- if not (isPrimitiveType .Spec.ValueSpec) ->
+					if <$v> == nil {
+						return <import "fmt">.Errorf("invalid set '<typeReference .Spec.ValueSpec>': contains nil value")
+					}
+					<- end>
+
 					if err := <encode .Spec.ValueSpec $v $sw>; err != nil {
 						return err
 					}
diff --git a/plugin/api/api.go b/plugin/api/api.go
index 623727a7..23e15550 100644
--- a/plugin/api/api.go
+++ b/plugin/api/api.go
@@ -803,7 +803,7 @@ type _List_Argument_ValueList []*Argument
 func (v _List_Argument_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*Argument', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -1042,7 +1042,10 @@ func _List_Argument_Encode(val []*Argument, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*Argument', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}
@@ -1575,7 +1578,7 @@ type _Map_ServiceID_Service_MapItemList map[ServiceID]*Service
 func (m _Map_ServiceID_Service_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[ServiceID]*Service', key [%v]: value is nil", k)
 		}
 		kw, err := k.ToWire()
 		if err != nil {
@@ -1613,7 +1616,7 @@ type _Map_ModuleID_Module_MapItemList map[ModuleID]*Module
 func (m _Map_ModuleID_Module_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[ModuleID]*Module', key [%v]: value is nil", k)
 		}
 		kw, err := k.ToWire()
 		if err != nil {
@@ -1993,6 +1996,9 @@ func _Map_ServiceID_Service_Encode(val map[ServiceID]*Service, sw stream.Writer)
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[ServiceID]*Service', key [%v]: value is nil", k)
+		}
 		if err := k.Encode(sw); err != nil {
 			return err
 		}
@@ -2016,6 +2022,9 @@ func _Map_ModuleID_Module_Encode(val map[ModuleID]*Module, sw stream.Writer) err
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[ModuleID]*Module', key [%v]: value is nil", k)
+		}
 		if err := k.Encode(sw); err != nil {
 			return err
 		}
@@ -2701,7 +2710,7 @@ type _Map_String_Binary_MapItemList map[string][]byte
 func (m _Map_String_Binary_MapItemList) ForEach(f func(wire.MapItem) error) error {
 	for k, v := range m {
 		if v == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", k)
+			return fmt.Errorf("invalid map 'map[string][]byte', key [%v]: value is nil", k)
 		}
 		kw, err := wire.NewValueString(k), error(nil)
 		if err != nil {
@@ -2845,6 +2854,9 @@ func _Map_String_Binary_Encode(val map[string][]byte, sw stream.Writer) error {
 	}
 
 	for k, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid map 'map[string][]byte', key [%v]: value is nil", k)
+		}
 		if err := sw.WriteString(k); err != nil {
 			return err
 		}
@@ -4147,7 +4159,7 @@ type _List_Function_ValueList []*Function
 func (v _List_Function_ValueList) ForEach(f func(wire.Value) error) error {
 	for i, x := range v {
 		if x == nil {
-			return fmt.Errorf("invalid [%v]: value is nil", i)
+			return fmt.Errorf("invalid list '[]*Function', index [%v]: value is nil", i)
 		}
 		w, err := x.ToWire()
 		if err != nil {
@@ -4375,7 +4387,10 @@ func _List_Function_Encode(val []*Function, sw stream.Writer) error {
 		return err
 	}
 
-	for _, v := range val {
+	for i, v := range val {
+		if v == nil {
+			return fmt.Errorf("invalid list '[]*Function', index [%v]: value is nil", i)
+		}
 		if err := v.Encode(sw); err != nil {
 			return err
 		}

From f7066fbc46d149718f60e3b128214b47acfb7413 Mon Sep 17 00:00:00 2001
From: Wit Riewrangboonya <wit@uber.com>
Date: Tue, 31 Aug 2021 16:42:55 -0700
Subject: [PATCH 3/3] Preparing release v1.29.1

---
 CHANGELOG.md                                                  | 4 ++--
 gen/internal/tests/collision/collision.go                     | 2 +-
 gen/internal/tests/constants/constants.go                     | 2 +-
 gen/internal/tests/containers/containers.go                   | 2 +-
 .../enum-text-marshal-strict/enum-text-marshal-strict.go      | 2 +-
 gen/internal/tests/enum_conflict/enum_conflict.go             | 2 +-
 gen/internal/tests/enums/enums.go                             | 2 +-
 gen/internal/tests/exceptions/exceptions.go                   | 2 +-
 gen/internal/tests/hyphenated-file/hyphenated-file.go         | 2 +-
 gen/internal/tests/hyphenated_file/hyphenated_file.go         | 2 +-
 gen/internal/tests/non_hyphenated/non_hyphenated.go           | 2 +-
 gen/internal/tests/nozap/nozap.go                             | 2 +-
 gen/internal/tests/other_constants/other_constants.go         | 2 +-
 gen/internal/tests/services/services.go                       | 2 +-
 gen/internal/tests/set_to_slice/set_to_slice.go               | 2 +-
 gen/internal/tests/structs/structs.go                         | 2 +-
 gen/internal/tests/typedefs/typedefs.go                       | 2 +-
 gen/internal/tests/unions/unions.go                           | 2 +-
 gen/internal/tests/uuid_conflict/uuid_conflict.go             | 2 +-
 internal/envelope/exception/exception.go                      | 2 +-
 plugin/api/api.go                                             | 2 +-
 version/version.go                                            | 2 +-
 22 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6ecd4506..cafeb9fd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [1.29.1] - 2021-08-31
 ### Fixed
 - Streaming encodes now handle `nil` items properly in containers.
 
@@ -422,7 +422,7 @@ this release.
 ### Added
 - Initial release.
 
-[Unreleased]: https://github.com/thriftrw/thriftrw-go/compare/v1.29.0...HEAD
+[1.29.1]: https://github.com/thriftrw/thriftrw-go/compare/v1.29.0...v1.29.1
 [1.29.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.28.0...v1.29.0
 [1.28.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.27.0...v1.28.0
 [1.27.0]: https://github.com/thriftrw/thriftrw-go/compare/v1.26.0...v1.27.0
diff --git a/gen/internal/tests/collision/collision.go b/gen/internal/tests/collision/collision.go
index 3a43a248..cdf19a08 100644
--- a/gen/internal/tests/collision/collision.go
+++ b/gen/internal/tests/collision/collision.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package collision
diff --git a/gen/internal/tests/constants/constants.go b/gen/internal/tests/constants/constants.go
index 2b7cd480..4d41d3f3 100644
--- a/gen/internal/tests/constants/constants.go
+++ b/gen/internal/tests/constants/constants.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package constants
diff --git a/gen/internal/tests/containers/containers.go b/gen/internal/tests/containers/containers.go
index e08d5441..09553cf8 100644
--- a/gen/internal/tests/containers/containers.go
+++ b/gen/internal/tests/containers/containers.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package containers
diff --git a/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go b/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
index dd74b4e8..419288c0 100644
--- a/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
+++ b/gen/internal/tests/enum-text-marshal-strict/enum-text-marshal-strict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package enum_text_marshal_strict
diff --git a/gen/internal/tests/enum_conflict/enum_conflict.go b/gen/internal/tests/enum_conflict/enum_conflict.go
index 6893f7e3..e27a0127 100644
--- a/gen/internal/tests/enum_conflict/enum_conflict.go
+++ b/gen/internal/tests/enum_conflict/enum_conflict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package enum_conflict
diff --git a/gen/internal/tests/enums/enums.go b/gen/internal/tests/enums/enums.go
index ad430e5c..e4d985ed 100644
--- a/gen/internal/tests/enums/enums.go
+++ b/gen/internal/tests/enums/enums.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package enums
diff --git a/gen/internal/tests/exceptions/exceptions.go b/gen/internal/tests/exceptions/exceptions.go
index c24fe897..b88742ff 100644
--- a/gen/internal/tests/exceptions/exceptions.go
+++ b/gen/internal/tests/exceptions/exceptions.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package exceptions
diff --git a/gen/internal/tests/hyphenated-file/hyphenated-file.go b/gen/internal/tests/hyphenated-file/hyphenated-file.go
index f17d00ae..96e9825a 100644
--- a/gen/internal/tests/hyphenated-file/hyphenated-file.go
+++ b/gen/internal/tests/hyphenated-file/hyphenated-file.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package hyphenated_file
diff --git a/gen/internal/tests/hyphenated_file/hyphenated_file.go b/gen/internal/tests/hyphenated_file/hyphenated_file.go
index d9f2c8ae..47736de7 100644
--- a/gen/internal/tests/hyphenated_file/hyphenated_file.go
+++ b/gen/internal/tests/hyphenated_file/hyphenated_file.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package hyphenated_file
diff --git a/gen/internal/tests/non_hyphenated/non_hyphenated.go b/gen/internal/tests/non_hyphenated/non_hyphenated.go
index 26fcb921..36cffb7f 100644
--- a/gen/internal/tests/non_hyphenated/non_hyphenated.go
+++ b/gen/internal/tests/non_hyphenated/non_hyphenated.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package non_hyphenated
diff --git a/gen/internal/tests/nozap/nozap.go b/gen/internal/tests/nozap/nozap.go
index 69ddbe3e..5a661cdf 100644
--- a/gen/internal/tests/nozap/nozap.go
+++ b/gen/internal/tests/nozap/nozap.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package nozap
diff --git a/gen/internal/tests/other_constants/other_constants.go b/gen/internal/tests/other_constants/other_constants.go
index 5d682a65..568354b7 100644
--- a/gen/internal/tests/other_constants/other_constants.go
+++ b/gen/internal/tests/other_constants/other_constants.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package other_constants
diff --git a/gen/internal/tests/services/services.go b/gen/internal/tests/services/services.go
index f9a9cbca..5d06595e 100644
--- a/gen/internal/tests/services/services.go
+++ b/gen/internal/tests/services/services.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package services
diff --git a/gen/internal/tests/set_to_slice/set_to_slice.go b/gen/internal/tests/set_to_slice/set_to_slice.go
index cbb89919..ead828df 100644
--- a/gen/internal/tests/set_to_slice/set_to_slice.go
+++ b/gen/internal/tests/set_to_slice/set_to_slice.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package set_to_slice
diff --git a/gen/internal/tests/structs/structs.go b/gen/internal/tests/structs/structs.go
index 9757c58f..86b2c94d 100644
--- a/gen/internal/tests/structs/structs.go
+++ b/gen/internal/tests/structs/structs.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package structs
diff --git a/gen/internal/tests/typedefs/typedefs.go b/gen/internal/tests/typedefs/typedefs.go
index 42faf8e0..ef388599 100644
--- a/gen/internal/tests/typedefs/typedefs.go
+++ b/gen/internal/tests/typedefs/typedefs.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package typedefs
diff --git a/gen/internal/tests/unions/unions.go b/gen/internal/tests/unions/unions.go
index f3fd9acb..e9195d27 100644
--- a/gen/internal/tests/unions/unions.go
+++ b/gen/internal/tests/unions/unions.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package unions
diff --git a/gen/internal/tests/uuid_conflict/uuid_conflict.go b/gen/internal/tests/uuid_conflict/uuid_conflict.go
index df3e2e0e..214e4518 100644
--- a/gen/internal/tests/uuid_conflict/uuid_conflict.go
+++ b/gen/internal/tests/uuid_conflict/uuid_conflict.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 package uuid_conflict
diff --git a/internal/envelope/exception/exception.go b/internal/envelope/exception/exception.go
index f67e31c3..56c25f84 100644
--- a/internal/envelope/exception/exception.go
+++ b/internal/envelope/exception/exception.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 // Copyright (c) 2021 Uber Technologies, Inc.
diff --git a/plugin/api/api.go b/plugin/api/api.go
index 23e15550..bdc6117a 100644
--- a/plugin/api/api.go
+++ b/plugin/api/api.go
@@ -1,4 +1,4 @@
-// Code generated by thriftrw v1.30.0. DO NOT EDIT.
+// Code generated by thriftrw v1.29.1. DO NOT EDIT.
 // @generated
 
 // Copyright (c) 2021 Uber Technologies, Inc.
diff --git a/version/version.go b/version/version.go
index 4a223c5b..c21d54d6 100644
--- a/version/version.go
+++ b/version/version.go
@@ -21,4 +21,4 @@
 package version
 
 // Version is the current ThriftRW version.
-const Version = "1.30.0"
+const Version = "1.29.1"