Add flag for specifying maximum number of redirects

integration/integration_test.go

@@ -387,6 +387,47 @@ func TestMain(t *testing.T) {
 		assertExitCode(t, 0, res)
 	})
 
+	t.Run("redirects", func(t *testing.T) {
+		var empty string
+		var urlStr atomic.Pointer[string]
+		urlStr.Store(&empty)
+
+		var count atomic.Int64
+		server := startServer(func(w http.ResponseWriter, r *http.Request) {
+			if count.Add(-1) < 0 {
+				w.WriteHeader(200)
+				return
+			}
+
+			w.Header().Set("Location", *urlStr.Load())
+			w.WriteHeader(301)
+		})
+		defer server.Close()
+		urlStr.Store(&server.URL)
+
+		// Success with no redirects.
+		res := runFetch(t, fetchPath, server.URL, "--redirects", "0")
+		assertExitCode(t, 0, res)
+
+		// Returns 301 with no redirects.
+		count.Store(1)
+		res = runFetch(t, fetchPath, server.URL, "--redirects", "0")
+		assertExitCode(t, 0, res)
+		assertBufContains(t, res.stderr, "301 Moved Permanently")
+
+		// Returns 200 with redirects.
+		count.Store(5)
+		res = runFetch(t, fetchPath, server.URL)
+		assertExitCode(t, 0, res)
+		assertBufContains(t, res.stderr, "200 OK")
+
+		// Returns an error when max redirects exceeded.
+		count.Store(2)
+		res = runFetch(t, fetchPath, server.URL, "--redirects", "1")
+		assertExitCode(t, 1, res)
+		assertBufContains(t, res.stderr, "exceeded maximum number of redirects")
+	})
+
 	t.Run("server sent events", func(t *testing.T) {
 		server := startServer(func(w http.ResponseWriter, r *http.Request) {
 			const data = ":comment\n\ndata:{\"key\":\"val\"}\n\nevent:ev1\ndata: this is my data\n\n"

internal/cli/app.go

@@ -44,6 +44,7 @@ type App struct {
 	Output       string
 	Proxy        *url.URL
 	QueryParams  []core.KeyVal
+	Redirects    *int
 	Silent       bool
 	Timeout      time.Duration
 	TLS          uint16
@@ -568,6 +569,25 @@ func (a *App) CLI() *CLI {
 					return nil
 				},
 			},
+			{
+				Short:       "",
+				Long:        "redirects",
+				Args:        "NUM",
+				Description: "Maximum number of redirects",
+				Default:     "",
+				IsSet: func() bool {
+					return a.Redirects != nil
+				},
+				Fn: func(value string) error {
+					n, err := strconv.Atoi(value)
+					if err != nil || n < 0 {
+						const usage = "must be a positive integer"
+						return flagValueError("redirects", value, usage)
+					}
+					a.Redirects = &n
+					return nil
+				},
+			},
 			{
 				Short:       "s",
 				Long:        "silent",

internal/client/client.go

@@ -4,6 +4,7 @@ import (
 	"compress/gzip"
 	"context"
 	"crypto/tls"
+	"fmt"
 	"io"
 	"net"
 	"net/http"
@@ -27,6 +28,7 @@ type ClientConfig struct {
 	HTTP      core.HTTPVersion
 	Insecure  bool
 	Proxy     *url.URL
+	Redirects *int
 	TLS       uint16
 }
 
@@ -80,11 +82,22 @@ func NewClient(cfg ClientConfig) *Client {
 	}
 	transport.TLSClientConfig.MinVersion = cfg.TLS
 
-	return &Client{
-		c: &http.Client{
-			Transport: transport,
-		},
+	// Optionally set the maximum number of redirects.
+	client := &http.Client{Transport: transport}
+	if cfg.Redirects != nil {
+		redirects := *cfg.Redirects
+		client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+			if redirects == 0 {
+				return http.ErrUseLastResponse
+			}
+			if len(via) > redirects {
+				return fmt.Errorf("exceeded maximum number of redirects: %d", redirects)
+			}
+			return nil
+		}
 	}
+
+	return &Client{c: client}
 }
 
 // RequestConfig represents the configuration for creating an HTTP request.

internal/fetch/fetch.go

@@ -45,6 +45,7 @@ type Request struct {
 	NoPager       bool
 	Output        string
 	PrinterHandle *printer.Handle
+	Redirects     *int
 	TLS           uint16
 	Verbosity     core.Verbosity
 
@@ -91,6 +92,7 @@ func fetch(ctx context.Context, r *Request) (int, error) {
 		HTTP:      r.HTTP,
 		Insecure:  r.Insecure,
 		Proxy:     r.Proxy,
+		Redirects: r.Redirects,
 		TLS:       r.TLS,
 	})
 	req, err := c.NewRequest(ctx, client.RequestConfig{

main.go

@@ -90,6 +90,7 @@ func main() {
 		NoPager:       app.NoPager,
 		Output:        app.Output,
 		PrinterHandle: printerHandle,
+		Redirects:     app.Redirects,
 		TLS:           app.TLS,
 		Verbosity:     verbosity,