fix: take care of the case where the requested height is above the head of latest da block height (#90)

* Return an err `no blob at a given height` in case there is no blob

* Fix lint

* Silly way of checking error for proxy test

* Add logic to check for the requested height

* Fix test

* Fix test

Author: yarikbratashchuk

test/dummy.go

@@ -16,8 +16,8 @@ import (
 // DefaultMaxBlobSize is the default max blob size
 const DefaultMaxBlobSize = 64 * 64 * 482
 
-// ErrNoBlobAtHeight is returned when there is no blob at given height.
-var ErrNoBlobAtHeight = errors.New("no blob at given height")
+// ErrTooHigh is returned when requested height is to high
+var ErrTooHigh = errors.New("given height is from the future")
 
 // DummyDA is a simple implementation of in-memory DA. Not production ready! Intended only for testing!
 //
@@ -85,10 +85,16 @@ func (d *DummyDA) Get(ctx context.Context, ids []da.ID, _ da.Namespace) ([]da.Bl
 func (d *DummyDA) GetIDs(ctx context.Context, height uint64, _ da.Namespace) ([]da.ID, error) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
+
+	if height > d.height {
+		return nil, ErrTooHigh
+	}
+
 	kvps, ok := d.data[height]
 	if !ok {
-		return nil, ErrNoBlobAtHeight
+		return nil, nil
 	}
+
 	ids := make([]da.ID, len(kvps))
 	for i, kv := range kvps {
 		ids[i] = kv.key

test/test_suite.go

@@ -3,7 +3,6 @@ package test
 import (
 	"bytes"
 	"context"
-	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -29,8 +28,8 @@ func RunDATestSuite(t *testing.T, d da.DA) {
 	t.Run("Concurrent read/write test", func(t *testing.T) {
 		ConcurrentReadWriteTest(t, d)
 	})
-	t.Run("No blobs at a given height", func(t *testing.T) {
-		NoBlobsAtHeightTest(t, d)
+	t.Run("Given height is from the future", func(t *testing.T) {
+		HeightFromFutureTest(t, d)
 	})
 }
 
@@ -138,28 +137,27 @@ func ConcurrentReadWriteTest(t *testing.T, d da.DA) {
 		defer wg.Done()
 		for i := uint64(1); i <= 100; i++ {
 			_, err := d.GetIDs(ctx, i, []byte{})
-			if err != nil && !strings.Contains(err.Error(), ErrNoBlobAtHeight.Error()) {
-				assert.NoError(t, err)
+			if err != nil {
+				assert.Equal(t, err.Error(), ErrTooHigh.Error())
 			}
 		}
 	}()
 
 	go func() {
 		defer wg.Done()
 		for i := uint64(1); i <= 100; i++ {
-			_, err := d.Submit(ctx, [][]byte{[]byte("test")}, 0, testNamespace)
+			_, err := d.Submit(ctx, [][]byte{[]byte("test")}, 0, []byte{})
 			assert.NoError(t, err)
 		}
 	}()
 
 	wg.Wait()
 }
 
-// NoBlobsAtHeightTest tests the case when there are no blobs at a given height in DA
-func NoBlobsAtHeightTest(t *testing.T, d da.DA) {
+// HeightFromFutureTest tests the case when the given height is from the future
+func HeightFromFutureTest(t *testing.T, d da.DA) {
 	ctx := context.TODO()
-	// GetIDs should return ErrNoBlobAtHeight when there are no blobs at a given height
-	_, err := d.GetIDs(ctx, 999999999, []byte{})
+	ids, err := d.GetIDs(ctx, 999999999, []byte{})
 	assert.Error(t, err)
-	assert.ErrorContains(t, err, ErrNoBlobAtHeight.Error())
+	assert.Nil(t, ids)
 }