A bit of niceness: more hints for first-time user.

cmd_mirror.go

@@ -15,15 +15,19 @@ func aptlyMirrorList(cmd *commander.Command, args []string) error {
 		return err
 	}
 
-	fmt.Printf("List of mirrors:\n")
-
 	repoCollection := debian.NewRemoteRepoCollection(context.database)
-	repoCollection.ForEach(func(repo *debian.RemoteRepo) error {
-		fmt.Printf(" * %s\n", repo)
-		return nil
-	})
 
-	fmt.Printf("\nTo get more information about repository, run `aptly mirror show <name>`.\n")
+	if repoCollection.Len() > 0 {
+		fmt.Printf("List of mirrors:\n")
+		repoCollection.ForEach(func(repo *debian.RemoteRepo) error {
+			fmt.Printf(" * %s\n", repo)
+			return nil
+		})
+
+		fmt.Printf("\nTo get more information about repository, run `aptly mirror show <name>`.\n")
+	} else {
+		fmt.Printf("No mirrors found, create one with `aptly mirror create ...`.\n")
+	}
 	return err
 }
 

cmd_snapshot.go

@@ -53,16 +53,21 @@ func aptlySnapshotList(cmd *commander.Command, args []string) error {
 		return err
 	}
 
-	fmt.Printf("List of snapshots:\n")
-
 	snapshotCollection := debian.NewSnapshotCollection(context.database)
-	snapshotCollection.ForEach(func(snapshot *debian.Snapshot) error {
-		fmt.Printf(" * %s\n", snapshot)
-		return nil
-	})
 
-	fmt.Printf("\nTo get more information about snapshot, run `aptly snapshot show <name>`.\n")
+	if snapshotCollection.Len() > 0 {
+		fmt.Printf("List of snapshots:\n")
+		snapshotCollection.ForEach(func(snapshot *debian.Snapshot) error {
+			fmt.Printf(" * %s\n", snapshot)
+			return nil
+		})
+
+		fmt.Printf("\nTo get more information about snapshot, run `aptly snapshot show <name>`.\n")
+	} else {
+		fmt.Printf("\nNo snapshots found, create one with `aptly snapshot create...`.\n")
+	}
 	return err
+
 }
 
 func aptlySnapshotShow(cmd *commander.Command, args []string) error {

debian/remote.go

@@ -358,3 +358,8 @@ func (collection *RemoteRepoCollection) ForEach(handler func(*RemoteRepo) error)
 	}
 	return err
 }
+
+// Len returns number of remote repos
+func (collection *RemoteRepoCollection) Len() int {
+	return len(collection.list)
+}

debian/remote_test.go

@@ -219,7 +219,7 @@ func (s *RemoteRepoCollectionSuite) TestUpdateLoadComplete(c *C) {
 	c.Assert(r.NumPackages(), Equals, 3)
 }
 
-func (s *RemoteRepoCollectionSuite) TestForEach(c *C) {
+func (s *RemoteRepoCollectionSuite) TestForEachAndLen(c *C) {
 	repo, _ := NewRemoteRepo("yandex", "http://mirror.yandex.ru/debian/", "squeeze", []string{"main"}, []string{})
 	s.collection.Add(repo)
 
@@ -231,6 +231,8 @@ func (s *RemoteRepoCollectionSuite) TestForEach(c *C) {
 	c.Assert(count, Equals, 1)
 	c.Assert(err, IsNil)
 
+	c.Check(s.collection.Len(), Equals, 1)
+
 	e := errors.New("c")
 
 	err = s.collection.ForEach(func(*RemoteRepo) error {

debian/snapshot.go

@@ -172,3 +172,9 @@ func (collection *SnapshotCollection) ForEach(handler func(*Snapshot) error) err
 	}
 	return err
 }
+
+// Len returns number of snapshots in collection
+// ForEach runs method for each snapshot
+func (collection *SnapshotCollection) Len() int {
+	return len(collection.list)
+}

debian/snapshot_test.go

@@ -112,7 +112,7 @@ func (s *SnapshotCollectionSuite) TestUpdateLoadComplete(c *C) {
 	c.Assert(snapshot.NumPackages(), Equals, 3)
 }
 
-func (s *SnapshotCollectionSuite) TestForEach(c *C) {
+func (s *SnapshotCollectionSuite) TestForEachAndLen(c *C) {
 	s.collection.Add(s.snapshot1)
 	s.collection.Add(s.snapshot2)
 
@@ -124,6 +124,8 @@ func (s *SnapshotCollectionSuite) TestForEach(c *C) {
 	c.Assert(count, Equals, 2)
 	c.Assert(err, IsNil)
 
+	c.Check(s.collection.Len(), Equals, 2)
+
 	e := errors.New("d")
 	err = s.collection.ForEach(func(*Snapshot) error {
 		return e