Add kind selection

Author: dmashuda

internal/dev_server/events/filter.go

@@ -0,0 +1,16 @@
+package events
+
+type Base struct {
+	Kind string `json:"kind"`
+}
+
+type Filter struct {
+	Kind *string
+}
+
+func (f Filter) Matches(e Base) bool {
+	if f.Kind == nil {
+		return true
+	}
+	return e.Kind == *f.Kind
+}

internal/dev_server/events/filter_test.go

@@ -0,0 +1,40 @@
+package events
+
+import (
+	"github.com/samber/lo"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestFilterMatches(t *testing.T) {
+	testCases := []struct {
+		name     string
+		filter   Filter
+		event    Base
+		expected bool
+	}{
+		{
+			name:     "no filter matches",
+			filter:   Filter{},
+			event:    Base{Kind: "kind"},
+			expected: true,
+		},
+		{
+			name:     "filter kind matches",
+			filter:   Filter{Kind: lo.ToPtr("kind")},
+			event:    Base{Kind: "kind"},
+			expected: true,
+		},
+		{
+			name:     "filter kind does not match",
+			filter:   Filter{Kind: lo.ToPtr("kind")},
+			event:    Base{Kind: "other"},
+			expected: false,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, tc.filter.Matches(tc.event))
+		})
+	}
+}

internal/dev_server/sdk/sdk_events.go

@@ -6,19 +6,40 @@ import (
 	"log"
 	"net/http"
 
+	"github.com/launchdarkly/ldcli/internal/dev_server/events"
 	"github.com/launchdarkly/ldcli/internal/dev_server/model"
 	"github.com/pkg/errors"
 )
 
+func newSdkEventObserver(updateChan chan<- Message, filter events.Filter) sdkEventObserver {
+	return sdkEventObserver{
+		updateChan: updateChan,
+		filter:     filter,
+	}
+}
+
 type sdkEventObserver struct {
 	updateChan chan<- Message
+	filter     events.Filter
 }
 
 func (o sdkEventObserver) Handle(message interface{}) {
 	str, ok := message.(json.RawMessage)
 	if !ok {
 		return
 	}
+
+	event := events.Base{}
+	err := json.Unmarshal(str, &event)
+	if err != nil {
+		log.Printf("sdkEventObserver: error unmarshaling event: %v", err)
+		return
+	}
+
+	if !o.filter.Matches(event) {
+		return
+	}
+
 	o.updateChan <- Message{Event: TYPE_PUT, Data: str}
 }
 
@@ -53,8 +74,15 @@ func SdkEventsTeeHandler(writer http.ResponseWriter, request *http.Request) {
 		Message{Event: TYPE_PUT, Data: []byte{}},
 	)
 	defer close(updateChan)
+	filter := events.Filter{}
+
+	query := request.URL.Query()
+	kind := query.Get("kind")
+	if kind != "" {
+		filter.Kind = &kind
+	}
 
-	observerId := observers.RegisterObserver(sdkEventObserver{updateChan})
+	observerId := observers.RegisterObserver(newSdkEventObserver(updateChan, filter))
 	defer func() {
 		ok := observers.DeregisterObserver(observerId)
 		if !ok {