Fix flux install command so it returns an error when unexpected arguments are passed

Signed-off-by: Vinícius Garcia <vingarcia00@gmail.com>

Author: VinGarcia

cmd/flux/install.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/manifoldco/promptui"
@@ -52,7 +53,7 @@ If a previous version is installed, then an in-place upgrade will be performed.`
   flux install --toleration-keys=node.kubernetes.io/dedicated-to-flux
 
   # Dry-run install
-  flux install --export | kubectl apply --dry-run=client -f- 
+  flux install --export | kubectl apply --dry-run=client -f-
 
   # Write install manifests to file
   flux install --export > flux-system.yaml`,
@@ -114,6 +115,10 @@ func NewInstallFlags() installFlags {
 }
 
 func installCmdRun(cmd *cobra.Command, args []string) error {
+	if len(args) > 0 {
+		return fmt.Errorf(`flux install received unexpected positional arguments: "%s"`, strings.Join(args, `", "`))
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), rootArgs.timeout)
 	defer cancel()
 

cmd/flux/install_test.go

@@ -37,6 +37,11 @@ func TestInstall(t *testing.T) {
 			args:   "install --namespace='@#[]'",
 			assert: assertError("namespace must be a valid DNS label: \"@#[]\""),
 		},
+		{
+			name:   "invalid namespace",
+			args:   "install unexpected pos arg --namespace=example",
+			assert: assertError("flux install received unexpected positional arguments: \"unexpected\", \"pos\", \"arg\""),
+		},
 	}
 
 	for _, tt := range tests {