Move opening of kube-tmuxp config file responsibility in to kubetmuxp

Author: arunvelsriram

cmd/generate.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"bufio"
 	"fmt"
 	"os"
 
@@ -17,20 +16,15 @@ var generateCmd = &cobra.Command{
 	Aliases: []string{"gen"},
 	Short:   "Generates tmuxp configs for various Kubernetes contexts",
 	Run: func(cmd *cobra.Command, args []string) {
-		reader, err := os.Open(cfgFile)
+		fs := &filesystem.Default{}
+		cmdr := &commander.Default{}
+		kubeCfg, err := kubeconfig.New(fs, cmdr)
 		if err != nil {
 			fmt.Println(err)
 			os.Exit(1)
 		}
-		bufioReader := bufio.NewReader(reader)
 
-		kubeCfg, err := kubeconfig.New(&filesystem.Default{}, &commander.Default{})
-		if err != nil {
-			fmt.Println(err)
-			os.Exit(1)
-		}
-
-		kubetmuxpCfg, err := kubetmuxp.NewConfig(bufioReader, kubeCfg)
+		kubetmuxpCfg, err := kubetmuxp.NewConfig(cfgFile, fs, kubeCfg)
 		if err != nil {
 			fmt.Println(err)
 			os.Exit(1)

pkg/filesystem/filesystem.go

@@ -1,6 +1,8 @@
 package filesystem
 
 import (
+	"bufio"
+	"io"
 	"os"
 
 	homedir "github.com/mitchellh/go-homedir"
@@ -10,6 +12,7 @@ import (
 type FileSystem interface {
 	Remove(file string) error
 	HomeDir() (string, error)
+	Open(file string) (io.Reader, error)
 }
 
 // Default represents the Operating System's filesystem
@@ -33,3 +36,12 @@ func (d *Default) HomeDir() (string, error) {
 
 	return home, nil
 }
+
+// Open opens a file for reading
+func (d *Default) Open(file string) (io.Reader, error) {
+	reader, err := os.Open(file)
+	if err != nil {
+		return reader, err
+	}
+	return bufio.NewReader(reader), err
+}

pkg/internal/mock/filesystem.go

@@ -2,10 +2,10 @@ package kubetmuxp
 
 import (
 	"fmt"
-	"io"
 	"io/ioutil"
 	"path"
 
+	"github.com/arunvelsriram/kube-tmuxp/pkg/filesystem"
 	"github.com/arunvelsriram/kube-tmuxp/pkg/kubeconfig"
 	yaml "gopkg.in/yaml.v2"
 )
@@ -60,11 +60,17 @@ type Projects []Project
 
 // Config represents kube-tmuxp config
 type Config struct {
-	Projects `yaml:"projects"`
-	kubeCfg  kubeconfig.KubeConfig
+	Projects   `yaml:"projects"`
+	filesystem filesystem.FileSystem
+	kubeCfg    kubeconfig.KubeConfig
 }
 
-func (c *Config) read(reader io.Reader) error {
+func (c *Config) load(cfgFile string) error {
+	reader, err := c.filesystem.Open(cfgFile)
+	if err != nil {
+		return err
+	}
+
 	data, err := ioutil.ReadAll(reader)
 	if err != nil {
 		return err
@@ -115,10 +121,13 @@ func (c *Config) Process() error {
 }
 
 // NewConfig creates a new kube-tmuxp Config
-func NewConfig(reader io.Reader, kubeCfg kubeconfig.KubeConfig) (Config, error) {
-	cfg := Config{kubeCfg: kubeCfg}
+func NewConfig(cfgFile string, fs filesystem.FileSystem, kubeCfg kubeconfig.KubeConfig) (Config, error) {
+	cfg := Config{
+		filesystem: fs,
+		kubeCfg:    kubeCfg,
+	}
 
-	if err := cfg.read(reader); err != nil {
+	if err := cfg.load(cfgFile); err != nil {
 		return cfg, err
 	}
 

pkg/kubetmuxp/kubetmuxp.go

@@ -1,6 +1,7 @@
 package kubetmuxp_test
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
@@ -20,22 +21,37 @@ func getKubeCfg(ctrl *gomock.Controller) kubeconfig.KubeConfig {
 }
 
 func TestNewConfig(t *testing.T) {
-	t.Run("should create a new kube-tmuxp config", func(t *testing.T) {
+	t.Run("should create a new kube-tmuxp config from file", func(t *testing.T) {
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 
+		mockFS := mock.NewFileSystem(ctrl)
 		reader := strings.NewReader("")
-		kubeCfg := getKubeCfg(ctrl)
-		kubetmuxpCfg, err := kubetmuxp.NewConfig(reader, kubeCfg)
+		mockFS.EXPECT().Open("kube-tmuxp-config.yaml").Return(reader, nil)
+
+		kubetmuxpCfg, err := kubetmuxp.NewConfig("kube-tmuxp-config.yaml", mockFS, kubeconfig.KubeConfig{})
 
 		assert.Nil(t, err)
 		assert.NotNil(t, kubetmuxpCfg)
 	})
 
+	t.Run("should return error if file cannot be opened", func(t *testing.T) {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+
+		mockFS := mock.NewFileSystem(ctrl)
+		mockFS.EXPECT().Open("kube-tmuxp-config.yaml").Return(nil, fmt.Errorf("some error"))
+
+		_, err := kubetmuxp.NewConfig("kube-tmuxp-config.yaml", mockFS, kubeconfig.KubeConfig{})
+
+		assert.EqualError(t, err, "some error")
+	})
+
 	t.Run("should read the kube-tmuxp configs", func(t *testing.T) {
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 
+		mockFS := mock.NewFileSystem(ctrl)
 		content := `
 projects:
 - name: test-project
@@ -47,10 +63,8 @@ projects:
     envs:
       TEST_ENV: test-value`
 		reader := strings.NewReader(content)
-		kubeCfg := getKubeCfg(ctrl)
-		kubetmuxpCfg, _ := kubetmuxp.NewConfig(reader, kubeCfg)
-
-		assert.NotNil(t, kubetmuxpCfg)
+		mockFS.EXPECT().Open("kube-tmuxp-config.yaml").Return(reader, nil)
+		kubetmuxpCfg, _ := kubetmuxp.NewConfig("kube-tmuxp-config.yaml", mockFS, kubeconfig.KubeConfig{})
 
 		expectedProjects := kubetmuxp.Projects{
 			{
@@ -68,16 +82,18 @@ projects:
 				},
 			},
 		}
+		assert.NotNil(t, kubetmuxpCfg)
 		assert.Equal(t, expectedProjects, kubetmuxpCfg.Projects)
 	})
 
 	t.Run("should return error if config cannot be read", func(t *testing.T) {
 		ctrl := gomock.NewController(t)
 		defer ctrl.Finish()
 
+		mockFS := mock.NewFileSystem(ctrl)
 		reader := strings.NewReader("invalid yaml")
-		kubeCfg := getKubeCfg(ctrl)
-		_, err := kubetmuxp.NewConfig(reader, kubeCfg)
+		mockFS.EXPECT().Open("kube-tmuxp-config.yaml").Return(reader, nil)
+		_, err := kubetmuxp.NewConfig("kube-tmuxp-config.yaml", mockFS, kubeconfig.KubeConfig{})
 
 		assert.NotNil(t, err)
 	})