cmd: Factor optional appname extraction from args

Author: Matthieu Nottale

cmd/helm.go

@@ -28,11 +28,7 @@ var helmCmd = &cobra.Command{
 			}
 			d[kv[0]] = kv[1]
 		}
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return renderer.Helm(app, helmComposeFiles, helmSettingsFile, d)
+		return renderer.Helm(firstOrEmpty(args), helmComposeFiles, helmSettingsFile, d)
 	},
 }
 

cmd/inspect.go

@@ -11,11 +11,7 @@ var inspectCmd = &cobra.Command{
 	Short: "Retrieve metadata for a given app package",
 	Args:  cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Inspect(app)
+		return packager.Inspect(firstOrEmpty(args))
 	},
 }
 

cmd/load.go

@@ -11,11 +11,7 @@ var loadCmd = &cobra.Command{
 	Short: "Load an app from docker",
 	Args:  cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Load(app)
+		return packager.Load(firstOrEmpty(args))
 	},
 }
 

cmd/pack.go

@@ -11,11 +11,7 @@ var packCmd = &cobra.Command{
 	Short: "Pack this app as a single file",
 	Args:  cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Pack(app, packOutputFile)
+		return packager.Pack(firstOrEmpty(args), packOutputFile)
 	},
 }
 

cmd/push.go

@@ -14,11 +14,7 @@ var pushCmd = &cobra.Command{
 		if pushTag == "" {
 			pushTag = "latest"
 		}
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Push(app, pushPrefix, pushTag)
+		return packager.Push(firstOrEmpty(args), pushPrefix, pushTag)
 	},
 }
 

cmd/render.go

@@ -36,11 +36,7 @@ Override is provided in different ways:
 			}
 			d[kv[0]] = kv[1]
 		}
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		rendered, err := renderer.Render(app, renderComposeFiles, renderSettingsFile, d)
+		rendered, err := renderer.Render(firstOrEmpty(args), renderComposeFiles, renderSettingsFile, d)
 		if err != nil {
 			return err
 		}

cmd/root.go

@@ -14,6 +14,13 @@ var rootCmd = &cobra.Command{
 	Long:  "",
 }
 
+func firstOrEmpty(list []string) string {
+	if len(list) != 0 {
+		return list[0]
+	}
+	return ""
+}
+
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {

cmd/save.go

@@ -14,11 +14,7 @@ var saveCmd = &cobra.Command{
 		if saveTag == "" {
 			saveTag = "latest"
 		}
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Save(app, savePrefix, saveTag)
+		return packager.Save(firstOrEmpty(args), savePrefix, saveTag)
 	},
 }
 

cmd/unpack.go

@@ -11,11 +11,7 @@ var unpackCmd = &cobra.Command{
 	Short: "Unpack the app to expose the content",
 	Args:  cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
-		app := ""
-		if len(args) > 0 {
-			app = args[0]
-		}
-		return packager.Unpack(app, unpackOutputDir)
+		return packager.Unpack(firstOrEmpty(args), unpackOutputDir)
 	},
 }