Adds a fuzz utility and test to make sure copy is complete.

agent/consul/structs/check_defintion_test.go

@@ -1,12 +1,15 @@
 package structs
 
 import (
+	"reflect"
 	"testing"
 
+	"github.com/google/gofuzz"
 	"github.com/hashicorp/consul/api"
+	"github.com/mitchellh/reflectwalk"
 )
 
-func TestAgentStructs_HealthCheck(t *testing.T) {
+func TestCheckDefinition_Defaults(t *testing.T) {
 	t.Parallel()
 	def := CheckDefinition{}
 	check := def.HealthCheck("node1")
@@ -16,3 +19,54 @@ func TestAgentStructs_HealthCheck(t *testing.T) {
 		t.Fatalf("bad: %v", check.Status)
 	}
 }
+
+type walker struct {
+	fields map[string]reflect.Value
+}
+
+func (w *walker) Struct(reflect.Value) error {
+	return nil
+}
+
+func (w *walker) StructField(f reflect.StructField, v reflect.Value) error {
+	w.fields[f.Name] = v
+	return nil
+}
+
+func mapFields(obj interface{}) map[string]reflect.Value {
+	w := &walker{make(map[string]reflect.Value)}
+	if err := reflectwalk.Walk(obj, w); err != nil {
+		panic(err)
+	}
+	return w.fields
+}
+
+func TestCheckDefinition_CheckType(t *testing.T) {
+	t.Parallel()
+
+	// Fuzz a definition to fill all its fields with data.
+	var def CheckDefinition
+	fuzz.New().Fuzz(&def)
+	orig := mapFields(def)
+
+	// Remap the ID field which changes name, and redact fields we don't
+	// expect in the copy.
+	orig["CheckID"] = orig["ID"]
+	delete(orig, "ID")
+	delete(orig, "ServiceID")
+	delete(orig, "Token")
+
+	// Now convert to a check type and ensure that all fields left match.
+	chk := def.CheckType()
+	copy := mapFields(chk)
+	for f, vo := range orig {
+		vc, ok := copy[f]
+		if !ok {
+			t.Fatalf("struct is missing field %q", f)
+		}
+
+		if !reflect.DeepEqual(vo.Interface(), vc.Interface()) {
+			t.Fatalf("copy skipped field %q", f)
+		}
+	}
+}