feat(mux): add wildcard (*) for more flexible route matching (#3631)

This pull request is for add some TODOs in `p/demo/mux` :

-  Add handling for NotFoundHandler
-  Add wildcard detection in route
Basic example:
```go
router.HandleFunc("r/user/*", func(rw *ResponseWriter, req *Request)) 
// match:
// "r/user/profile"           
// "r/user/posts"       
// "r/user/home/avatar"

examples/gno.land/p/demo/mux/handler.gno

@@ -7,6 +7,8 @@ type Handler struct {
 
 type HandlerFunc func(*ResponseWriter, *Request)
 
-// TODO: type ErrHandlerFunc func(*ResponseWriter, *Request) error
-// TODO: NotFoundHandler
+type ErrHandlerFunc func(*ResponseWriter, *Request) error
+
+type NotFoundHandler func(*ResponseWriter, *Request)
+
 // TODO: AutomaticIndex

examples/gno.land/p/demo/mux/request.gno

@@ -18,24 +18,29 @@ type Request struct {
 
 // GetVar retrieves a variable from the path based on routing rules.
 func (r *Request) GetVar(key string) string {
-	var (
-		handlerParts = strings.Split(r.HandlerPath, "/")
-		reqParts     = strings.Split(r.Path, "/")
-	)
-
-	for i := 0; i < len(handlerParts); i++ {
-		handlerPart := handlerParts[i]
+	handlerParts := strings.Split(r.HandlerPath, "/")
+	reqParts := strings.Split(r.Path, "/")
+	reqIndex := 0
+	for handlerIndex := 0; handlerIndex < len(handlerParts); handlerIndex++ {
+		handlerPart := handlerParts[handlerIndex]
 		switch {
 		case handlerPart == "*":
-			// XXX: implement a/b/*/d/e
-			panic("not implemented")
+			// If a wildcard "*" is found, consume all remaining segments
+			wildcardParts := reqParts[reqIndex:]
+			reqIndex = len(reqParts)                // Consume all remaining segments
+			return strings.Join(wildcardParts, "/") // Return all remaining segments as a string
 		case strings.HasPrefix(handlerPart, "{") && strings.HasSuffix(handlerPart, "}"):
+			// If a variable of the form {param} is found we compare it with the key
 			parameter := handlerPart[1 : len(handlerPart)-1]
 			if parameter == key {
-				return reqParts[i]
+				return reqParts[reqIndex]
 			}
+			reqIndex++
 		default:
-			// continue
+			if reqIndex >= len(reqParts) || handlerPart != reqParts[reqIndex] {
+				return ""
+			}
+			reqIndex++
 		}
 	}
 

examples/gno.land/p/demo/mux/request_test.gno

@@ -1,8 +1,10 @@
 package mux
 
 import (
-	"fmt"
 	"testing"
+
+	"gno.land/p/demo/uassert"
+	"gno.land/p/demo/ufmt"
 )
 
 func TestRequest_GetVar(t *testing.T) {
@@ -12,28 +14,35 @@ func TestRequest_GetVar(t *testing.T) {
 		getVarKey      string
 		expectedOutput string
 	}{
+
 		{"users/{id}", "users/123", "id", "123"},
 		{"users/123", "users/123", "id", ""},
 		{"users/{id}", "users/123", "nonexistent", ""},
-		{"a/{b}/c/{d}", "a/42/c/1337", "b", "42"},
-		{"a/{b}/c/{d}", "a/42/c/1337", "d", "1337"},
-		{"{a}", "foo", "a", "foo"},
-		// TODO: wildcards: a/*/c
-		// TODO: multiple patterns per slashes: a/{b}-{c}/d
-	}
+		{"users/{userId}/posts/{postId}", "users/123/posts/456", "userId", "123"},
+		{"users/{userId}/posts/{postId}", "users/123/posts/456", "postId", "456"},
+
+		// Wildcards
+		{"*", "users/123", "*", "users/123"},
+		{"*", "users/123/posts/456", "*", "users/123/posts/456"},
+		{"*", "users/123/posts/456/comments/789", "*", "users/123/posts/456/comments/789"},
+		{"users/*", "users/john/posts", "*", "john/posts"},
+		{"users/*/comments", "users/jane/comments", "*", "jane/comments"},
+		{"api/*/posts/*", "api/v1/posts/123", "*", "v1/posts/123"},
 
+		// wildcards and parameters
+		{"api/{version}/*", "api/v1/user/settings", "version", "v1"},
+	}
 	for _, tt := range cases {
-		name := fmt.Sprintf("%s-%s", tt.handlerPath, tt.reqPath)
+		name := ufmt.Sprintf("%s-%s", tt.handlerPath, tt.reqPath)
 		t.Run(name, func(t *testing.T) {
 			req := &Request{
 				HandlerPath: tt.handlerPath,
 				Path:        tt.reqPath,
 			}
-
 			output := req.GetVar(tt.getVarKey)
-			if output != tt.expectedOutput {
-				t.Errorf("Expected '%q, but got %q", tt.expectedOutput, output)
-			}
+			uassert.Equal(t, tt.expectedOutput, output,
+				"handler: %q, path: %q, key: %q",
+				tt.handlerPath, tt.reqPath, tt.getVarKey)
 		})
 	}
 }

examples/gno.land/p/demo/mux/router.gno

@@ -5,7 +5,7 @@ import "strings"
 // Router handles the routing and rendering logic.
 type Router struct {
 	routes          []Handler
-	NotFoundHandler HandlerFunc
+	NotFoundHandler NotFoundHandler
 }
 
 // NewRouter creates a new Router instance.
@@ -23,8 +23,14 @@ func (r *Router) Render(reqPath string) string {
 
 	for _, route := range r.routes {
 		patParts := strings.Split(route.Pattern, "/")
-
-		if len(patParts) != len(reqParts) {
+		wildcard := false
+		for _, part := range patParts {
+			if part == "*" {
+				wildcard = true
+				break
+			}
+		}
+		if !wildcard && len(patParts) != len(reqParts) {
 			continue
 		}
 
@@ -34,7 +40,7 @@ func (r *Router) Render(reqPath string) string {
 			reqPart := reqParts[i]
 
 			if patPart == "*" {
-				continue
+				break
 			}
 			if strings.HasPrefix(patPart, "{") && strings.HasSuffix(patPart, "}") {
 				continue
@@ -63,12 +69,31 @@ func (r *Router) Render(reqPath string) string {
 	return res.Output()
 }
 
-// Handle registers a route and its handler function.
+// HandleFunc registers a route and its handler function.
 func (r *Router) HandleFunc(pattern string, fn HandlerFunc) {
 	route := Handler{Pattern: pattern, Fn: fn}
 	r.routes = append(r.routes, route)
 }
 
+// HandleErrFunc registers a route and its error handler function.
+func (r *Router) HandleErrFunc(pattern string, fn ErrHandlerFunc) {
+
+	// Convert ErrHandlerFunc to regular HandlerFunc
+	handler := func(res *ResponseWriter, req *Request) {
+		if err := fn(res, req); err != nil {
+			res.Write("Error: " + err.Error())
+		}
+	}
+
+	r.HandleFunc(pattern, handler)
+}
+
+// SetNotFoundHandler sets custom message for 404 defaultNotFoundHandler.
+func (r *Router) SetNotFoundHandler(handler NotFoundHandler) {
+	r.NotFoundHandler = handler
+}
+
+// stripQueryString removes query string from the request path.
 func stripQueryString(reqPath string) string {
 	i := strings.Index(reqPath, "?")
 	if i == -1 {

examples/gno.land/p/demo/mux/router_test.gno

@@ -72,7 +72,33 @@ func TestRouter_Render(t *testing.T) {
 				})
 			},
 		},
-
+		{
+			label:          "wildcard in route",
+			path:           "hello/Alice/Bob",
+			expectedOutput: "Matched: Alice/Bob",
+			setupHandler: func(t *testing.T, r *Router) {
+				r.HandleFunc("hello/*", func(rw *ResponseWriter, req *Request) {
+					path := req.GetVar("*")
+					uassert.Equal(t, "Alice/Bob", path)
+					uassert.Equal(t, "hello/Alice/Bob", req.Path)
+					rw.Write("Matched: " + path)
+				})
+			},
+		},
+		{
+			label:          "wildcard in route with query string",
+			path:           "hello/Alice/Bob?foo=bar",
+			expectedOutput: "Matched: Alice/Bob",
+			setupHandler: func(t *testing.T, r *Router) {
+				r.HandleFunc("hello/*", func(rw *ResponseWriter, req *Request) {
+					path := req.GetVar("*")
+					uassert.Equal(t, "Alice/Bob", path)
+					uassert.Equal(t, "hello/Alice/Bob?foo=bar", req.RawPath)
+					uassert.Equal(t, "hello/Alice/Bob", req.Path)
+					rw.Write("Matched: " + path)
+				})
+			},
+		},
 		// TODO: {"hello", "Hello, world!"},
 		// TODO: hello/, /hello, hello//Alice, hello/Alice/, hello/Alice/Bob, etc
 	}