func (d *Downloader) getDesiredImageFile() (string, error) {
file, err := d.fs.Open(config.DesiredImageLocatorFile())
if err != nil {
return "", err
}
defer file.Close()
reader := bufio.NewReader(file)
desiredImageString, err := reader.ReadString('\n')
if err != nil {
return "", err
}
desiredImageFile := strings.TrimSpace(config.CacheDirectory() + "/" + d.fs.Base(desiredImageString))
return desiredImageFile, nil
}
func TestLoadDesiredAgentFailReadDesired(t *testing.T) {
mockCtrl := gomock.NewController(t)
defer mockCtrl.Finish()
mockFS := NewMockfileSystem(mockCtrl)
mockFS.EXPECT().Open(config.DesiredImageLocatorFile()).Return(ioutil.NopCloser(&bytes.Buffer{}), nil)
d := &Downloader{
fs: mockFS,
}
_, err := d.LoadDesiredAgent()
if err == nil {
t.Error("Expected error to be returned but got nil")
}
}
func TestLoadDesiredAgent(t *testing.T) {
mockCtrl := gomock.NewController(t)
defer mockCtrl.Finish()
desiredImage := "my-new-agent-image"
mockFS := NewMockfileSystem(mockCtrl)
mockFS.EXPECT().Open(config.DesiredImageLocatorFile()).Return(ioutil.NopCloser(bytes.NewBufferString(desiredImage+"\n")), nil)
mockFS.EXPECT().Base(gomock.Any()).Return(desiredImage + "\n")
mockFS.EXPECT().Open(config.CacheDirectory() + "/" + desiredImage)
d := &Downloader{
fs: mockFS,
}
d.LoadDesiredAgent()
}