Add DeleteQueue method to Inspector

- Added ErrQueueNotFound and ErrQueueNotEmpty type to indicate the kind
  of an error returned from the method.

inspector.go

@@ -124,6 +124,45 @@ func (i *Inspector) History(qname string, n int) ([]*DailyStats, error) {
 	return res, nil
 }
 
+// ErrQueueNotFound indicates that the specified queue does not exist.
+type ErrQueueNotFound struct {
+	qname string
+}
+
+func (e *ErrQueueNotFound) Error() string {
+	return fmt.Sprintf("queue %q does not exist", e.qname)
+}
+
+// ErrQueueNotEmpty indicates that the specified queue is not empty.
+type ErrQueueNotEmpty struct {
+	qname string
+}
+
+func (e *ErrQueueNotEmpty) Error() string {
+	return fmt.Sprintf("queue %q is not empty", e.qname)
+}
+
+// DeleteQueue removes the specified queue.
+//
+// If force is set to true, DeleteQueue will remove the queue regardless of
+// the queue size as long as no tasks are active in the queue.
+// If force is set to false, DeleteQueue will remove the queue only if
+// the queue is empty.
+//
+// If the specified queue does not exist, DeleteQueue returns ErrQueueNotFound.
+// If force is set to false and the specified queue is not empty, DeleteQueue
+// returns ErrQueueNotEmpty.
+func (i *Inspector) DeleteQueue(qname string, force bool) error {
+	err := i.rdb.RemoveQueue(qname, force)
+	if _, ok := err.(*rdb.ErrQueueNotFound); ok {
+		return &ErrQueueNotFound{qname}
+	}
+	if _, ok := err.(*rdb.ErrQueueNotEmpty); ok {
+		return &ErrQueueNotEmpty{qname}
+	}
+	return err
+}
+
 // PendingTask is a task in a queue and is ready to be processed.
 type PendingTask struct {
 	*Task

inspector_test.go

@@ -50,6 +50,207 @@ func TestInspectorQueues(t *testing.T) {
 
 }
 
+func TestInspectorDeleteQueue(t *testing.T) {
+	r := setup(t)
+	defer r.Close()
+	inspector := NewInspector(getRedisConnOpt(t))
+	defer inspector.Close()
+	m1 := h.NewTaskMessage("task1", nil)
+	m2 := h.NewTaskMessage("task2", nil)
+	m3 := h.NewTaskMessageWithQueue("task3", nil, "custom")
+	m4 := h.NewTaskMessageWithQueue("task4", nil, "custom")
+
+	tests := []struct {
+		pending   map[string][]*base.TaskMessage
+		active    map[string][]*base.TaskMessage
+		scheduled map[string][]base.Z
+		retry     map[string][]base.Z
+		dead      map[string][]base.Z
+		qname     string // queue to remove
+		force     bool
+	}{
+		{
+			pending: map[string][]*base.TaskMessage{
+				"default": {m1, m2},
+				"custom":  {},
+			},
+			active: map[string][]*base.TaskMessage{
+				"default": {},
+				"custom":  {},
+			},
+			scheduled: map[string][]base.Z{
+				"default": {},
+				"custom":  {},
+			},
+			retry: map[string][]base.Z{
+				"default": {},
+				"custom":  {},
+			},
+			dead: map[string][]base.Z{
+				"default": {},
+				"custom":  {},
+			},
+			qname: "custom",
+			force: false,
+		},
+		{
+			pending: map[string][]*base.TaskMessage{
+				"default": {m1, m2},
+				"custom":  {m3},
+			},
+			active: map[string][]*base.TaskMessage{
+				"default": {},
+				"custom":  {},
+			},
+			scheduled: map[string][]base.Z{
+				"default": {},
+				"custom":  {{Message: m4, Score: time.Now().Unix()}},
+			},
+			retry: map[string][]base.Z{
+				"default": {},
+				"custom":  {},
+			},
+			dead: map[string][]base.Z{
+				"default": {},
+				"custom":  {},
+			},
+			qname: "custom",
+			force: true, // allow removing non-empty queue
+		},
+	}
+
+	for _, tc := range tests {
+		h.FlushDB(t, r)
+		h.SeedAllPendingQueues(t, r, tc.pending)
+		h.SeedAllActiveQueues(t, r, tc.active)
+		h.SeedAllScheduledQueues(t, r, tc.scheduled)
+		h.SeedAllRetryQueues(t, r, tc.retry)
+		h.SeedAllDeadQueues(t, r, tc.dead)
+
+		err := inspector.DeleteQueue(tc.qname, tc.force)
+		if err != nil {
+			t.Errorf("DeleteQueue(%q, %t) = %v, want nil",
+				tc.qname, tc.force, err)
+			continue
+		}
+		if r.SIsMember(base.AllQueues, tc.qname).Val() {
+			t.Errorf("%q is a member of %q", tc.qname, base.AllQueues)
+		}
+	}
+}
+
+func TestInspectorDeleteQueueErrorQueueNotEmpty(t *testing.T) {
+	r := setup(t)
+	defer r.Close()
+	inspector := NewInspector(getRedisConnOpt(t))
+	defer inspector.Close()
+	m1 := h.NewTaskMessage("task1", nil)
+	m2 := h.NewTaskMessage("task2", nil)
+	m3 := h.NewTaskMessageWithQueue("task3", nil, "custom")
+	m4 := h.NewTaskMessageWithQueue("task4", nil, "custom")
+
+	tests := []struct {
+		pending   map[string][]*base.TaskMessage
+		active    map[string][]*base.TaskMessage
+		scheduled map[string][]base.Z
+		retry     map[string][]base.Z
+		dead      map[string][]base.Z
+		qname     string // queue to remove
+		force     bool
+	}{
+		{
+			pending: map[string][]*base.TaskMessage{
+				"default": {m1, m2},
+			},
+			active: map[string][]*base.TaskMessage{
+				"default": {m3, m4},
+			},
+			scheduled: map[string][]base.Z{
+				"default": {},
+			},
+			retry: map[string][]base.Z{
+				"default": {},
+			},
+			dead: map[string][]base.Z{
+				"default": {},
+			},
+			qname: "default",
+			force: false,
+		},
+	}
+
+	for _, tc := range tests {
+		h.FlushDB(t, r)
+		h.SeedAllPendingQueues(t, r, tc.pending)
+		h.SeedAllActiveQueues(t, r, tc.active)
+		h.SeedAllScheduledQueues(t, r, tc.scheduled)
+		h.SeedAllRetryQueues(t, r, tc.retry)
+		h.SeedAllDeadQueues(t, r, tc.dead)
+
+		err := inspector.DeleteQueue(tc.qname, tc.force)
+		if _, ok := err.(*ErrQueueNotEmpty); !ok {
+			t.Errorf("DeleteQueue(%v, %t) did not return ErrQueueNotEmpty",
+				tc.qname, tc.force)
+		}
+	}
+}
+
+func TestInspectorDeleteQueueErrorQueueNotFound(t *testing.T) {
+	r := setup(t)
+	defer r.Close()
+	inspector := NewInspector(getRedisConnOpt(t))
+	defer inspector.Close()
+	m1 := h.NewTaskMessage("task1", nil)
+	m2 := h.NewTaskMessage("task2", nil)
+	m3 := h.NewTaskMessageWithQueue("task3", nil, "custom")
+	m4 := h.NewTaskMessageWithQueue("task4", nil, "custom")
+
+	tests := []struct {
+		pending   map[string][]*base.TaskMessage
+		active    map[string][]*base.TaskMessage
+		scheduled map[string][]base.Z
+		retry     map[string][]base.Z
+		dead      map[string][]base.Z
+		qname     string // queue to remove
+		force     bool
+	}{
+		{
+			pending: map[string][]*base.TaskMessage{
+				"default": {m1, m2},
+			},
+			active: map[string][]*base.TaskMessage{
+				"default": {m3, m4},
+			},
+			scheduled: map[string][]base.Z{
+				"default": {},
+			},
+			retry: map[string][]base.Z{
+				"default": {},
+			},
+			dead: map[string][]base.Z{
+				"default": {},
+			},
+			qname: "nonexistent",
+			force: false,
+		},
+	}
+
+	for _, tc := range tests {
+		h.FlushDB(t, r)
+		h.SeedAllPendingQueues(t, r, tc.pending)
+		h.SeedAllActiveQueues(t, r, tc.active)
+		h.SeedAllScheduledQueues(t, r, tc.scheduled)
+		h.SeedAllRetryQueues(t, r, tc.retry)
+		h.SeedAllDeadQueues(t, r, tc.dead)
+
+		err := inspector.DeleteQueue(tc.qname, tc.force)
+		if _, ok := err.(*ErrQueueNotFound); !ok {
+			t.Errorf("DeleteQueue(%v, %t) did not return ErrQueueNotFound",
+				tc.qname, tc.force)
+		}
+	}
+}
+
 func TestInspectorCurrentStats(t *testing.T) {
 	r := setup(t)
 	defer r.Close()
@@ -66,7 +267,7 @@ func TestInspectorCurrentStats(t *testing.T) {
 
 	tests := []struct {
 		pending   map[string][]*base.TaskMessage
-		inProgress map[string][]*base.TaskMessage
+		active    map[string][]*base.TaskMessage
 		scheduled map[string][]base.Z
 		retry     map[string][]base.Z
 		dead      map[string][]base.Z
@@ -81,7 +282,7 @@ func TestInspectorCurrentStats(t *testing.T) {
 				"critical": {m5},
 				"low":      {m6},
 			},
-			inProgress: map[string][]*base.TaskMessage{
+			active: map[string][]*base.TaskMessage{
 				"default":  {m2},
 				"critical": {},
 				"low":      {},
@@ -134,7 +335,7 @@ func TestInspectorCurrentStats(t *testing.T) {
 	for _, tc := range tests {
 		asynqtest.FlushDB(t, r)
 		asynqtest.SeedAllPendingQueues(t, r, tc.pending)
-		asynqtest.SeedAllActiveQueues(t, r, tc.inProgress)
+		asynqtest.SeedAllActiveQueues(t, r, tc.active)
 		asynqtest.SeedAllScheduledQueues(t, r, tc.scheduled)
 		asynqtest.SeedAllRetryQueues(t, r, tc.retry)
 		asynqtest.SeedAllDeadQueues(t, r, tc.dead)
@@ -314,13 +515,13 @@ func TestInspectorListActiveTasks(t *testing.T) {
 
 	tests := []struct {
 		desc   string
-		inProgress map[string][]*base.TaskMessage
+		active map[string][]*base.TaskMessage
 		qname  string
 		want   []*ActiveTask
 	}{
 		{
 			desc: "with a few active tasks",
-			inProgress: map[string][]*base.TaskMessage{
+			active: map[string][]*base.TaskMessage{
 				"default": {m1, m2},
 				"custom":  {m3, m4},
 			},
@@ -334,7 +535,7 @@ func TestInspectorListActiveTasks(t *testing.T) {
 
 	for _, tc := range tests {
 		asynqtest.FlushDB(t, r)
-		asynqtest.SeedAllActiveQueues(t, r, tc.inProgress)
+		asynqtest.SeedAllActiveQueues(t, r, tc.active)
 
 		got, err := inspector.ListActiveTasks(tc.qname)
 		if err != nil {

internal/rdb/inspect.go

@@ -745,7 +745,6 @@ func (r *RDB) RemoveQueue(qname string, force bool) error {
 			return err
 		}
 	}
-
 	return r.client.SRem(base.AllQueues, qname).Err()
 }
 

internal/rdb/inspect_test.go

@@ -2707,10 +2707,10 @@ func TestRemoveQueue(t *testing.T) {
 
 		err := r.RemoveQueue(tc.qname, tc.force)
 		if err != nil {
-			t.Errorf("(*RDB).RemoveQueue(%q) = %v, want nil", tc.qname, err)
+			t.Errorf("(*RDB).RemoveQueue(%q, %t) = %v, want nil",
+				tc.qname, tc.force, err)
 			continue
 		}
-
 		if r.client.SIsMember(base.AllQueues, tc.qname).Val() {
 			t.Errorf("%q is a member of %q", tc.qname, base.AllQueues)
 		}