Fix rule with environment (#698)

ffuser/user.go

@@ -39,3 +39,10 @@ func (u *User) IsAnonymous() bool {
 func (u *User) GetCustom() map[string]interface{} {
 	return u.custom
 }
+
+// AddCustomAttribute allows to add a custom attribute into the user.
+func (u *User) AddCustomAttribute(name string, value interface{}) {
+	if name != "" {
+		u.custom[name] = value
+	}
+}

ffuser/user_test.go

@@ -0,0 +1,44 @@
+package ffuser_test
+
+import (
+	"github.com/stretchr/testify/assert"
+	"github.com/thomaspoignant/go-feature-flag/ffuser"
+	"testing"
+)
+
+func TestUser_AddCustomAttribute(t *testing.T) {
+	type args struct {
+		name  string
+		value interface{}
+	}
+	tests := []struct {
+		name string
+		user ffuser.User
+		args args
+		want map[string]interface{}
+	}{
+		{
+			name: "trying to add nil value",
+			user: ffuser.NewUser("123"),
+			args: args{},
+			want: map[string]interface{}{},
+		},
+		{
+			name: "add valid element",
+			user: ffuser.NewUser("123"),
+			args: args{
+				name:  "test",
+				value: "test",
+			},
+			want: map[string]interface{}{
+				"test": "test",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tt.user.AddCustomAttribute(tt.args.name, tt.args.value)
+			assert.Equal(t, tt.want, tt.user.GetCustom())
+		})
+	}
+}

internal/flag/internal_flag.go

@@ -60,6 +60,10 @@ func (f *InternalFlag) Value(
 ) (interface{}, ResolutionDetails) {
 	f.applyScheduledRolloutSteps()
 
+	if evaluationCtx.Environment != "" {
+		user.AddCustomAttribute("env", evaluationCtx.Environment)
+	}
+
 	if f.IsDisable() || f.isExperimentationOver() {
 		return evaluationCtx.DefaultSdkValue, ResolutionDetails{
 			Variant:   VariationSDKDefault,

internal/flag/internal_flag_test.go

@@ -1159,6 +1159,44 @@ func TestInternalFlag_Value(t *testing.T) {
 				Cacheable: true,
 			},
 		},
+		{
+			name: "Should use the environment as a rule criteria",
+			flag: flag.InternalFlag{
+				Variations: &map[string]*interface{}{
+					"A": testconvert.Interface(false),
+					"B": testconvert.Interface(true),
+				},
+				Rules: &[]flag.Rule{
+					{
+						Query:           testconvert.String("env == \"development\""),
+						VariationResult: testconvert.String("A"),
+					},
+					{
+						Query: testconvert.String("(env == \"production\") " +
+							"or (env == \"staging\") or (env == \"qa\")"),
+						VariationResult: testconvert.String("B"),
+					},
+				},
+				DefaultRule: &flag.Rule{
+					VariationResult: testconvert.String("B"),
+				},
+			},
+			args: args{
+				flagName: "feature",
+				user:     ffuser.NewUserBuilder("1").Build(),
+				evaluationCtx: flag.EvaluationContext{
+					DefaultSdkValue: true,
+					Environment:     "development",
+				},
+			},
+			want: false,
+			want1: flag.ResolutionDetails{
+				Variant:   "A",
+				Reason:    flag.ReasonTargetingMatch,
+				Cacheable: true,
+				RuleIndex: testconvert.Int(0),
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {