communicator/ssh: Test to verify keychain impls ssh.ClientKeyring

communicator/ssh/keychain_test.go

 package ssh
 
-import "testing"
+import (
+	"code.google.com/p/go.crypto/ssh"
+	"testing"
+)
 
 const testPrivateKey = `-----BEGIN RSA PRIVATE KEY-----
 MIIBOwIBAAJBALdGZxkXDAjsYk10ihwU6Id2KeILz1TAJuoq4tOgDWxEEGeTrcld
@@ -19,3 +22,11 @@ func TestAddPEMKey(t *testing.T) {
 		t.Fatalf("error while adding key: %s", err)
 	}
 }
+
+func TestSimpleKeyChain_ImplementsClientkeyring(t *testing.T) {
+	var raw interface{}
+	raw = &SimpleKeychain{}
+	if _, ok := raw.(ssh.ClientKeyring); !ok {
+		t.Fatal("SimpleKeychain is not a valid ssh.ClientKeyring")
+	}
+}