Make DynamoDb.getSubscribersInState private

Now that ProcessSubscribersInState is in place, there's no need for
clients to bother managing the complexity of getSubscribersInState.

db/database.go

@@ -31,9 +31,6 @@ type Database interface {
 	Get(ctx context.Context, email string) (*Subscriber, error)
 	Put(ctx context.Context, subscriber *Subscriber) error
 	Delete(ctx context.Context, email string) error
-	GetSubscribersInState(
-		context.Context, SubscriberStatus, StartKey,
-	) ([]*Subscriber, StartKey, error)
 	ProcessSubscribersInState(
 		context.Context, SubscriberStatus, SubscriberProcessor,
 	) error

db/dynamodb.go

@@ -337,7 +337,7 @@ func (db *DynamoDb) ProcessSubscribersInState(
 	var next StartKey
 
 	for {
-		subs, next, err = db.GetSubscribersInState(ctx, status, next)
+		subs, next, err = db.getSubscribersInState(ctx, status, next)
 
 		if err != nil {
 			return
@@ -359,7 +359,7 @@ type dynamoDbStartKey struct {
 
 func (*dynamoDbStartKey) isDbStartKey() {}
 
-func (db *DynamoDb) GetSubscribersInState(
+func (db *DynamoDb) getSubscribersInState(
 	ctx context.Context, state SubscriberStatus, startKey StartKey,
 ) (subs []*Subscriber, nextStartKey StartKey, err error) {
 	const errFmt = "failed to get %s subscribers: %s"

db/dynamodb_contract_test.go

@@ -317,7 +317,7 @@ func TestDynamoDb(t *testing.T) {
 		})
 	})
 
-	t.Run("ProcessSubscribers", func(t *testing.T) {
+	t.Run("ProcessSubscribersInState", func(t *testing.T) {
 		emails := make(
 			[]string,
 			0,
@@ -358,20 +358,7 @@ func TestDynamoDb(t *testing.T) {
 		setup(t)
 		defer teardown()
 
-		t.Run("GetSubscribersInStateSucceeds", func(t *testing.T) {
-			subs, next, err := testDb.GetSubscribersInState(
-				ctx, SubscriberVerified, nil,
-			)
-
-			assert.NilError(t, err)
-			assert.Assert(t, is.Nil(next))
-
-			// The ordering here isn't necessarily guaranteed, but expected
-			// to be the same as insertion.
-			assert.DeepEqual(t, testVerifiedSubscribers, subs)
-		})
-
-		t.Run("ProcessSubscribersInStateSucceeds", func(t *testing.T) {
+		t.Run("Succeeds", func(t *testing.T) {
 			subs := &[]*Subscriber{}
 			f := SubscriberFunc(func(s *Subscriber) bool {
 				*subs = append(*subs, s)

db/dynamodb_test.go

@@ -427,7 +427,7 @@ func TestGetSubscribersInState(t *testing.T) {
 	t.Run("Succeeds", func(t *testing.T) {
 		dyndb, _ := setupDbWithSubscribers()
 
-		subs, next, err := dyndb.GetSubscribersInState(
+		subs, next, err := dyndb.getSubscribersInState(
 			ctx, SubscriberVerified, nil,
 		)
 
@@ -439,7 +439,7 @@ func TestGetSubscribersInState(t *testing.T) {
 	t.Run("FailsIfNewScanInputFails", func(t *testing.T) {
 		dyndb, _ := setupDbWithSubscribers()
 
-		subs, next, err := dyndb.GetSubscribersInState(
+		subs, next, err := dyndb.getSubscribersInState(
 			ctx, SubscriberVerified, &bogusDbStartKey{})
 
 		assert.Assert(t, is.Nil(subs))
@@ -453,7 +453,7 @@ func TestGetSubscribersInState(t *testing.T) {
 		dyndb, client := setupDbWithSubscribers()
 		client.scanErr = errors.New("scanning error")
 
-		subs, next, err := dyndb.GetSubscribersInState(
+		subs, next, err := dyndb.getSubscribersInState(
 			ctx, SubscriberVerified, nil,
 		)
 
@@ -472,7 +472,7 @@ func TestGetSubscribersInState(t *testing.T) {
 			string(status): toDynamoDbTimestamp(testTimestamp),
 		})
 
-		subs, _, err := dyndb.GetSubscribersInState(
+		subs, _, err := dyndb.getSubscribersInState(
 			ctx, SubscriberVerified, nil,
 		)