Feature: add option to lowercase the parameters before sorting.

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.20.x]
+        go-version: [1.21.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps:

README.md

@@ -6,29 +6,63 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/teodorescuserban/caddy-argsort)](https://goreportcard.com/report/github.com/teodorescuserban/caddy-argsort)
 
 This is a caddy plugin. Works with caddy 2.
-Sort the request query arguments.
+Sort the request query arguments. Optionally case insensitive.
 
 ## Usage
 
-Caddyfile:
+### Set the module order
+
+You will need to specify the execution order of this module in your caddyfile. This is done in the global options block.
 
 ```caddyfile
-# Add this block in top-level settings:
 {
     ...
-    order argsort before rewrite
+    order argsort before header
     ...
 }
+```
+
+### Simple usage
+
+Once the order has been set in the global options block, use `argsort` in any server block
+
+```caddyfile
+{
+    order argsort before header
+}
 
-# use argsort keyword in any server
 :8881 {
     header Content-Type "text/html; charset=utf-8"
     respond "Hello."
     argsort
 }
+```
+
+### Optional case insensitive usage
+
+Once the order has been set in the global options block, use `argsort lowecase` in any server block
+
+```caddyfile
+{
+    order argsort before header
+}
+
+:8881 {
+    header Content-Type "text/html; charset=utf-8"
+    respond "Hello."
+    argsort lowercase
+}
+```
+
+### Forward the normalized request to an upstream
+
+Once the order has been set in the global options block, you ensure query arguments sorting for an upstream server
+
+```caddyfile
+{
+    order argsort before header
+}
 
-# or ensure query arguments sorting then passing it to another server
-# (useful when using other web server in the backend)
 :8882 {
     argsort
     reverse_proxy localhost:8883

argsort.go

@@ -2,6 +2,8 @@ package argsort
 
 import (
 	"net/http"
+	"net/url"
+	"strings"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
@@ -17,6 +19,7 @@ func init() {
 // Middleware implements an HTTP handler that
 // reorders the query arguments.
 type Middleware struct {
+	Lowercase bool `json:"lowercase,omitempty"`
 }
 
 // CaddyModule returns the Caddy module information.
@@ -39,14 +42,37 @@ func (m *Middleware) Validate() error {
 
 // ServeHTTP implements caddyhttp.MiddlewareHandler.
 func (m Middleware) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
-	// url.Values.Encode() will just do the sort for us
-	r.URL.RawQuery = r.URL.Query().Encode()
+	// url.Values.Encode() is doing the sort for us
+	if m.Lowercase {
+		values := url.Values{}
+		for k, s := range r.URL.Query() {
+			for _, v := range s {
+				values.Add(strings.ToLower(k), v)
+			}
+		}
+		r.URL.RawQuery = values.Encode()
+	} else {
+		r.URL.RawQuery = r.URL.Query().Encode()
+	}
+
 	return next.ServeHTTP(w, r)
 }
 
 // UnmarshalCaddyfile implements caddyfile.Unmarshaler.
-func (m *Middleware) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
-	d.Next() // consume directive name
+// argsort [lower]
+func (a *Middleware) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
+	// Set default value for Lower
+	a.Lowercase = false
+
+	for d.Next() {
+		if d.NextArg() {
+			if d.Val() == "lowercase" {
+				a.Lowercase = true
+			} else {
+				return d.ArgErr()
+			}
+		}
+	}
 	return nil
 }
 

test/Caddyfile.3

@@ -0,0 +1,10 @@
+{
+        debug
+        order argsort before rewrite
+}
+
+:2015 {
+        argsort
+        header Content-Type "text/html; charset=utf-8"
+        respond "{http.request.uri.query}"
+}

test/Caddyfile.4

@@ -0,0 +1,10 @@
+{
+        debug
+        order argsort before rewrite
+}
+
+:2015 {
+        argsort lowercase
+        header Content-Type "text/html; charset=utf-8"
+        respond "{http.request.uri.query}"
+}

test/run-test

@@ -31,7 +31,7 @@ echobold() {
 
 test() {
     echobold "test case ${1}"
-    $XCADDY run --config test/Caddyfile.${1}&
+    $XCADDY run --adapter caddyfile --config test/Caddyfile.${1}&
     pid="$!"
     retry $(cat test/test-${1}.req) > output${1}
     diff output${1} test/test-${1}.res
@@ -51,3 +51,7 @@ $XCADDY list-modules
 test "1"
 
 test "2"
+
+test "3"
+
+test "4"

test/test-2.req

@@ -1 +1 @@
-http://localhost:2015/baz?z=bar&a=foo
+http://localhost:2015/baz?z=bar&m=baz&a=foo

test/test-2.res

@@ -1 +1 @@
-a=foo&z=bar
+a=foo&m=baz&z=bar

test/test-3.req

@@ -0,0 +1 @@
+http://localhost:2015/baz?Z=bar&M=baz&a=foo

test/test-3.res

@@ -0,0 +1 @@
+M=baz&Z=bar&a=foo

test/test-4.req

@@ -0,0 +1 @@
+http://localhost:2015/baz?Z=bar&M=baz&a=foo

test/test-4.res

@@ -0,0 +1 @@
+a=foo&m=baz&z=bar