From 3900c1e86f533f1443e77368ad2c98ea94fc3c04 Mon Sep 17 00:00:00 2001
From: Jason Bedard <jason@aspect.dev>
Date: Wed, 9 Feb 2022 11:30:13 -0800
Subject: [PATCH] fix: interceptors Run() when list of interceptors is empty

---
 pkg/interceptors/run.go      |  8 ++++----
 pkg/interceptors/run_test.go | 26 +++++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/pkg/interceptors/run.go b/pkg/interceptors/run.go
index 7a16a6e79..3cf78bd90 100644
--- a/pkg/interceptors/run.go
+++ b/pkg/interceptors/run.go
@@ -28,13 +28,13 @@ type Interceptor func(ctx context.Context, cmd *cobra.Command, args []string, ne
 func Run(interceptors []Interceptor, fn RunEContextFn) RunEFn {
 	return func(cmd *cobra.Command, args []string) error {
 		current := fn
-		for i := len(interceptors) - 1; i > 0; i-- {
-			j := i
+		for i := len(interceptors) - 1; i >= 0; i-- {
+			interceptor := interceptors[i]
 			next := current
 			current = func(ctx context.Context, cmd *cobra.Command, args []string) error {
-				return interceptors[j](ctx, cmd, args, next)
+				return interceptor(ctx, cmd, args, next)
 			}
 		}
-		return interceptors[0](cmd.Context(), cmd, args, current)
+		return current(cmd.Context(), cmd, args)
 	}
 }
diff --git a/pkg/interceptors/run_test.go b/pkg/interceptors/run_test.go
index 630c080a4..696968ec8 100644
--- a/pkg/interceptors/run_test.go
+++ b/pkg/interceptors/run_test.go
@@ -16,7 +16,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-func ExampleRun() {
+func ExampleRun_interceptor_order() {
 	g := NewGomega(func(message string, callerSkip ...int) {
 		log.Fatal(message)
 	})
@@ -49,6 +49,30 @@ func ExampleRun() {
 	// interceptor 1
 }
 
+func ExampleRun_nointerceptors() {
+	g := NewGomega(func(message string, callerSkip ...int) {
+		log.Fatal(message)
+	})
+
+	ctx := context.Background()
+	args := []string{"foo", "bar"}
+	os.Args = append([]string{"fake"}, args...)
+	cmd := &cobra.Command{Use: "fake"}
+	cmd.RunE = Run(
+		[]Interceptor{},
+		func(_ctx context.Context, _cmd *cobra.Command, _args []string) error {
+			g.Expect(_cmd).To(Equal(cmd))
+			g.Expect(_args).To(Equal(args))
+			fmt.Printf("called %q with %v\n", _cmd.Use, _args)
+			return nil
+		},
+	)
+	cmd.ExecuteContext(ctx)
+
+	// Output:
+	// called "fake" with [foo bar]
+}
+
 func LoggingInterceptor1() Interceptor {
 	return func(ctx context.Context, cmd *cobra.Command, args []string, next RunEContextFn) error {
 		fmt.Println("interceptor 1")