Unit test for coordination windows watch function

pkg/tbtc/coordination_test.go

@@ -1,8 +1,11 @@
 package tbtc
 
 import (
-	"github.com/keep-network/keep-core/internal/testutils"
+	"context"
 	"testing"
+	"time"
+
+	"github.com/keep-network/keep-core/internal/testutils"
 )
 
 func TestCoordinationWindow_ActivePhaseEndBlock(t *testing.T) {
@@ -58,4 +61,58 @@ func TestCoordinationWindow_IsAfterActivePhase(t *testing.T) {
 		false,
 		window.isAfter(nextWindow),
 	)
-}
+}
+
+func TestWatchCoordinationWindows(t *testing.T) {
+	watchBlocksFn := func(ctx context.Context) <-chan uint64 {
+		blocksChan := make(chan uint64)
+
+		go func() {
+			ticker := time.NewTicker(1 * time.Millisecond)
+			defer ticker.Stop()
+
+			block := uint64(0)
+
+			for {
+				select {
+				case <-ticker.C:
+					block++
+					blocksChan <- block
+				case <-ctx.Done():
+					return
+				}
+			}
+		}()
+
+		return blocksChan
+	}
+
+	receivedWindows := make([]*coordinationWindow, 0)
+	onWindowFn := func(window *coordinationWindow) {
+		receivedWindows = append(receivedWindows, window)
+	}
+
+	ctx, cancelCtx := context.WithTimeout(
+		context.Background(),
+		2000*time.Millisecond,
+	)
+	defer cancelCtx()
+
+	go watchCoordinationWindows(ctx, watchBlocksFn, onWindowFn)
+
+	<-ctx.Done()
+
+	testutils.AssertIntsEqual(t, "received windows", 2, len(receivedWindows))
+	testutils.AssertIntsEqual(
+		t,
+		"first window",
+		900,
+		int(receivedWindows[0].coordinationBlock),
+	)
+	testutils.AssertIntsEqual(
+		t,
+		"second window",
+		1800,
+		int(receivedWindows[1].coordinationBlock),
+	)
+}