Add Align to align HTTP headers

IMHO this makes stuff rather more readable/scannable. Some people may
not like it, so I added it as an option.

Will automatically align to the longest header; I modified the
sortHeaderKeys() so we don't need to do an extra loop for it.

Also pass the Host header to printHeaders() so it's aligned too. Do some
special-fu to make sure it still prints as the first.

Before;

	* Request at 2024-09-19 15:19:15.459694244 +0100 IST m=+1.001660288
	* Request to http://localhost:8081/api/3/ping
	> GET /api/3/ping HTTP/1.1
	> Host: localhost:8081
	> Accept: application/json; charset=utf-8
	> Authorization: ApiKey ████████████████████
	> Content-Type: application/json; charset=utf-8
	> User-Agent: alfred/

	< HTTP/1.1 200 OK
	< Cache-Control: no-store,no-cache
	< Content-Length: 88
	< Content-Security-Policy: default-src 'self'; img-src 'self' blob: data:;
	< Content-Type: application/json; charset=utf-8
	< Date: Thu, 19 Sep 2024 14:19:15 GMT
	< Referrer-Policy: same-origin
	< X-Content-Type-Options: nosniff
	< X-Frame-Options: SAMEORIGIN
	< X-Powered-By: Alfred
	< X-Xss-Protection: 1; mode=block

	{
		"ftm_version": "3.7.0",
		"role": 4,
		"title": "Alfred",
		"version": "d67f396b"
	}

	* Request took 9.251101ms

After:

	* Request at 2024-09-19 15:18:45.255328802 +0100 IST m=+1.001249794
	* Request to http://localhost:8081/api/3/ping
	> GET /api/3/ping HTTP/1.1
	> Host:          localhost:8081
	> Accept:        application/json; charset=utf-8
	> Authorization: ApiKey ████████████████████
	> Content-Type:  application/json; charset=utf-8
	> User-Agent:    alfred/

	< HTTP/1.1 200 OK
	< Cache-Control:           no-store,no-cache
	< Content-Length:          88
	< Content-Security-Policy: default-src 'self'; img-src 'self' blob: data:;
	< Content-Type:            application/json; charset=utf-8
	< Date:                    Thu, 19 Sep 2024 14:18:45 GMT
	< Referrer-Policy:         same-origin
	< X-Content-Type-Options:  nosniff
	< X-Frame-Options:         SAMEORIGIN
	< X-Powered-By:            Alfred
	< X-Xss-Protection:        1; mode=block

	{
		"ftm_version": "3.7.0",
		"role": 4,
		"title": "Alfred",
		"version": "d67f396b"
	}

	* Request took 9.251101ms

httpretty.go

@@ -117,6 +117,9 @@ type Logger struct {
 	// Colors set ANSI escape codes that terminals use to print text in different colors.
 	Colors bool
 
+	// Align HTTP headers.
+	Align bool
+
 	// Formatters for the request and response bodies.
 	// No standard formatters are used. You need to add what you want to use explicitly.
 	// We provide a JSONFormatter for convenience (add it manually).

httpretty_test.go

@@ -51,6 +51,38 @@ func TestPrintRequest(t *testing.T) {
 	}
 }
 
+func TestPrintRequestWithAlign(t *testing.T) {
+	t.Parallel()
+	var req, err = http.NewRequest(http.MethodPost, "http://wxww.example.com/", nil)
+	if err != nil {
+		panic(err)
+	}
+	req.Header.Set("Header", "foo")
+	req.Header.Set("Other-Header", "bar")
+
+	logger := &Logger{
+		TLS:            true,
+		RequestHeader:  true,
+		RequestBody:    true,
+		ResponseHeader: true,
+		ResponseBody:   true,
+		Align:          true,
+	}
+	var buf bytes.Buffer
+	logger.SetOutput(&buf)
+	logger.PrintRequest(req)
+
+	want := `> POST / HTTP/1.1
+> Host:         wxww.example.com
+> Header:       foo
+> Other-Header: bar
+
+`
+	if got := buf.String(); got != want {
+		t.Errorf("PrintRequest(req) = %v, wanted %v", got, want)
+	}
+}
+
 func TestPrintRequestWithColors(t *testing.T) {
 	t.Parallel()
 	var req, err = http.NewRequest(http.MethodPost, "http://wxww.example.com/", nil)

printer.go

@@ -9,6 +9,7 @@ import (
 	"mime"
 	"net"
 	"net/http"
+	"slices"
 	"sort"
 	"strings"
 	"time"
@@ -486,59 +487,71 @@ func (p *printer) printHeaders(prefix rune, h http.Header) {
 	if !p.logger.SkipSanitize {
 		h = header.Sanitize(header.DefaultSanitizers, h)
 	}
-	skipped := p.logger.cloneSkipHeader()
-	for _, key := range sortHeaderKeys(h) {
+
+	longest, sorted := sortHeaderKeys(h, p.logger.cloneSkipHeader())
+	for _, key := range sorted {
 		for _, v := range h[key] {
-			if _, skip := skipped[key]; skip {
-				continue
+			var pad string
+			if p.logger.Align {
+				pad = strings.Repeat(" ", longest-len(key))
 			}
-			p.printf("%c %s%s %s\n", prefix,
+			p.printf("%c %s%s %s%s\n", prefix,
 				p.format(color.FgBlue, color.Bold, key),
 				p.format(color.FgRed, ":"),
+				pad,
 				p.format(color.FgYellow, v))
 		}
 	}
 }
 
-func sortHeaderKeys(h http.Header) []string {
-	keys := make([]string, 0, len(h))
+func sortHeaderKeys(h http.Header, skipped map[string]struct{}) (int, []string) {
+	var (
+		keys    = make([]string, 0, len(h))
+		longest int
+	)
 	for key := range h {
+		if _, skip := skipped[key]; skip {
+			continue
+		}
 		keys = append(keys, key)
+		if l := len(key); l > longest {
+			longest = l
+		}
 	}
 	sort.Strings(keys)
-	return keys
+	if i := slices.Index(keys, "Host"); i > -1 {
+		keys = append([]string{"Host"}, slices.Delete(keys, i, i+1)...)
+	}
+	return longest, keys
 }
 
 func (p *printer) printRequestHeader(req *http.Request) {
 	p.printf("> %s %s %s\n",
 		p.format(color.FgBlue, color.Bold, req.Method),
 		p.format(color.FgYellow, req.URL.RequestURI()),
 		p.format(color.FgBlue, req.Proto))
-	host := req.Host
-	if host == "" {
-		host = req.URL.Host
-	}
-	if host != "" {
-		p.printf("> %s%s %s\n",
-			p.format(color.FgBlue, color.Bold, "Host"),
-			p.format(color.FgRed, ":"),
-			p.format(color.FgYellow, host),
-		)
-	}
-	p.printHeaders('>', addHeaderContentLength(req))
+	p.printHeaders('>', addRequestHeaders(req))
 	p.println()
 }
 
-// addHeaderContentLength returns a copy of the given header with an additional header, Content-Length, if it's known.
-func addHeaderContentLength(req *http.Request) http.Header {
-	if req.ContentLength == 0 && len(req.Header.Values("Content-Length")) == 0 {
-		return req.Header
-	}
+// addRequestHeaders returns a copy of the given header with an additional headers set, if known.
+func addRequestHeaders(req *http.Request) http.Header {
 	cp := http.Header{}
 	for k, v := range req.Header {
 		cp[k] = v
 	}
-	cp.Set("Content-Length", fmt.Sprintf("%d", req.ContentLength))
+
+	if len(req.Header.Values("Content-Length")) == 0 && req.ContentLength > 0 {
+		cp.Set("Content-Length", fmt.Sprintf("%d", req.ContentLength))
+	}
+
+	host := req.Host
+	if host == "" {
+		host = req.URL.Host
+	}
+	if host != "" {
+		cp.Set("Host", host)
+	}
 	return cp
 }