In/NotIn and const rules show enum values for enum type

rule_comparison.md

@@ -55,6 +55,7 @@
 | const                  |✅|✅|✅|✅|✅|
 | defined_only           |✅|✅|✅|✅|✅|
 | in/not_in              |✅|✅|✅|✅|✅|
+| in/not_in/const <br> enum value in error |✅|✅|✅|✅|❌|
 
 ## Messages
 | Constraint Rule | Go | GoGo | C++ | Java | Python |

templates/cc/const.go

@@ -1,9 +1,13 @@
 package cc
 
-const constTpl = `{{ $r := .Rules }}
+const constTpl = `{{ $f := .Field }}{{ $r := .Rules }}
 	{{ if $r.Const }}
 		if ({{ accessor . }} != {{ lit $r.GetConst }}) {
+			{{- if isEnum $f }}
+			{{ err . "value must equal " (enumVal $f $r.GetConst) }}
+			{{- else }}
 			{{ err . "value must equal " (lit $r.GetConst) }}
+			{{- end }}
 		}
 	{{ end }}
 `

templates/cc/in.go

@@ -3,11 +3,19 @@ package cc
 const inTpl = `{{ $f := .Field -}}{{ $r := .Rules -}}
 	{{- if $r.In }}
 		if ({{ lookup $f "InLookup" }}.find(static_cast<decltype({{ lookup $f "InLookup" }})::key_type>({{ accessor . }})) == {{ lookup $f "InLookup" }}.end()) {
+			{{- if isEnum $f }}
+			{{ err . "value must be in list " (enumList $f $r.In) }}
+			{{- else }}
 			{{ err . "value must be in list " $r.In }}
+			{{- end }}
 		}
 	{{- else if $r.NotIn }}
 		if ({{ lookup $f "NotInLookup" }}.find(static_cast<decltype({{ lookup $f "NotInLookup" }})::key_type>({{ accessor . }})) != {{ lookup $f "NotInLookup" }}.end()) {
+			{{- if isEnum $f }}
+			{{ err . "value must not be in list " (enumList $f $r.NotIn) }}
+			{{- else }}
 			{{ err . "value must not be in list " $r.NotIn }}
+			{{- end }}
 		}
 	{{- end }}
 `

templates/goshared/const.go

@@ -1,9 +1,13 @@
 package goshared
 
-const constTpl = `{{ $r := .Rules }}
+const constTpl = `{{ $f := .Field }}{{ $r := .Rules }}
 	{{ if $r.Const }}
 		if {{ accessor . }} != {{ lit $r.GetConst }} {
+			{{- if isEnum $f }}
+			err := {{ err . "value must equal " (enumVal $f $r.GetConst) }}
+			{{- else }}
 			err := {{ err . "value must equal " $r.GetConst }}
+			{{- end }}
 			if !all { return err }
 			errors = append(errors, err)
 		}

templates/goshared/in.go

@@ -3,13 +3,21 @@ package goshared
 const inTpl = `{{ $f := .Field }}{{ $r := .Rules }}
 	{{ if $r.In }}
 		if _, ok := {{ lookup $f "InLookup" }}[{{ accessor . }}]; !ok {
+			{{- if isEnum $f }}
+			err := {{ err . "value must be in list " (enumList $f $r.In) }}
+			{{- else }}
 			err := {{ err . "value must be in list " $r.In }}
+			{{- end }}
 			if !all { return err }
 			errors = append(errors, err)
 		}
 	{{ else if $r.NotIn }}
 		if _, ok := {{ lookup $f "NotInLookup" }}[{{ accessor . }}]; ok {
+			{{- if isEnum $f }}
+			err := {{ err . "value must not be in list " (enumList $f $r.NotIn) }}
+			{{- else }}
 			err := {{ err . "value must not be in list " $r.NotIn }}
+			{{- end }}
 			if !all { return err }
 			errors = append(errors, err)
 		}

templates/shared/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "functions.go",
         "reflection.go",
         "well_known.go",
+        "enums.go"
     ],
     importpath = "github.com/envoyproxy/protoc-gen-validate/templates/shared",
     visibility = ["//visibility:public"],

templates/shared/enums.go

@@ -0,0 +1,35 @@
+package shared
+
+import (
+	"fmt"
+	"strings"
+
+	pgs "github.com/lyft/protoc-gen-star"
+)
+
+func isEnum(f pgs.Field) bool {
+	return f.Type().IsEnum()
+}
+
+// enumList - if type is ENUM, enum values are returned
+func enumList(f pgs.Field, list []int32) string {
+	stringList := make([]string, 0, len(list))
+	if enum := f.Type().Enum(); enum != nil {
+		for _, n := range list {
+			stringList = append(stringList, enum.Values()[n].Name().String())
+		}
+	} else {
+		for _, n := range list {
+			stringList = append(stringList, fmt.Sprint(n))
+		}
+	}
+	return "[" + strings.Join(stringList, " ") + "]"
+}
+
+// enumVal - if type is ENUM, enum value is returned
+func enumVal(f pgs.Field, val int32) string {
+	if enum := f.Type().Enum(); enum != nil {
+		return enum.Values()[val].Name().String()
+	}
+	return fmt.Sprint(val)
+}

templates/shared/functions.go

@@ -3,7 +3,7 @@ package shared
 import (
 	"text/template"
 
-	"github.com/lyft/protoc-gen-star"
+	pgs "github.com/lyft/protoc-gen-star"
 )
 
 func RegisterFunctions(tpl *template.Template, params pgs.Parameters) {
@@ -16,5 +16,8 @@ func RegisterFunctions(tpl *template.Template, params pgs.Parameters) {
 		"has":       Has,
 		"needs":     Needs,
 		"fileneeds": FileNeeds,
+		"isEnum":    isEnum,
+		"enumList":  enumList,
+		"enumVal":   enumVal,
 	})
 }