vweb: add an overridable .not_found() method, for making a custom 404 page + tests fixes (#17936)

vlib/vweb/README.md

@@ -378,6 +378,19 @@ pub fn (mut app App) with_auth() bool {
 }
 ```
 
+### Fallback route
+You can implement a fallback `not_found` route that is called when a request is made and no 
+matching route is found.
+
+**Example:**
+
+``` v ignore
+pub fn (mut app App) not_found() vweb.Result {
+	app.set_status(404, 'Not Found')
+	return app.html('<h1>Page not found</h1>')
+}
+```
+
 ### Controllers
 Controllers can be used to split up app logic so you are able to have one struct 
 per `"/"`.  E.g. a struct `Admin` for urls starting with `"/admin"` and a struct `Foo`

vlib/vweb/tests/controller_duplicate_server.v

@@ -14,7 +14,7 @@ struct Admin {
 }
 
 ['/admin/duplicate']
-fn (mut app App) duplicate() vweb.Result {
+pub fn (mut app App) duplicate() vweb.Result {
 	return app.text('duplicate')
 }
 

vlib/vweb/tests/controller_test.v

@@ -1,9 +1,6 @@
 import os
 import time
-import json
-import net
 import net.http
-import io
 
 const (
 	sport           = 12382
@@ -91,6 +88,21 @@ fn test_other_path() {
 	assert x.body == 'Other path'
 }
 
+fn test_different_404() {
+	res_app := http.get('http://${localserver}/zxcnbnm') or { panic(err) }
+	assert res_app.status() == .not_found
+	assert res_app.body == '404 From App'
+
+	res_admin := http.get('http://${localserver}/admin/JHKAJA') or { panic(err) }
+	assert res_admin.status() == .not_found
+	assert res_admin.body == '404 From Admin'
+
+	// Other doesn't have a custom 404 so the vweb.Context's not_found is expected
+	res_other := http.get('http://${localserver}/other/unknown') or { panic(err) }
+	assert res_other.status() == .not_found
+	assert res_other.body == '404 Not Found'
+}
+
 fn test_shutdown() {
 	// This test is guaranteed to be called last.
 	// It sends a request to the server to shutdown.

vlib/vweb/tests/controller_test_server.v

@@ -46,32 +46,42 @@ fn main() {
 }
 
 ['/']
-fn (mut app App) home() vweb.Result {
+pub fn (mut app App) home() vweb.Result {
 	return app.text('App')
 }
 
 ['/path']
-fn (mut app App) app_path() vweb.Result {
+pub fn (mut app App) app_path() vweb.Result {
 	return app.text('App path')
 }
 
+pub fn (mut app App) not_found() vweb.Result {
+	app.set_status(404, 'Not Found')
+	return app.text('404 From App')
+}
+
 ['/']
-fn (mut app Admin) admin_home() vweb.Result {
+pub fn (mut app Admin) admin_home() vweb.Result {
 	return app.text('Admin')
 }
 
 ['/path']
-fn (mut app Admin) admin_path() vweb.Result {
+pub fn (mut app Admin) admin_path() vweb.Result {
 	return app.text('Admin path')
 }
 
+pub fn (mut app Admin) not_found() vweb.Result {
+	app.set_status(404, 'Not Found')
+	return app.text('404 From Admin')
+}
+
 ['/']
-fn (mut app Other) other_home() vweb.Result {
+pub fn (mut app Other) other_home() vweb.Result {
 	return app.text('Other')
 }
 
 ['/path']
-fn (mut app Other) other_path() vweb.Result {
+pub fn (mut app Other) other_path() vweb.Result {
 	return app.text('Other path')
 }
 

vlib/vweb/tests/vweb_test.v

@@ -124,14 +124,16 @@ fn test_http_client_index() {
 }
 
 fn test_http_client_404() {
+	server := 'http://${localserver}'
 	url_404_list := [
-		'http://${localserver}/zxcnbnm',
-		'http://${localserver}/JHKAJA',
-		'http://${localserver}/unknown',
+		'/zxcnbnm',
+		'/JHKAJA',
+		'/unknown',
 	]
 	for url in url_404_list {
-		res := http.get(url) or { panic(err) }
+		res := http.get('${server}${url}') or { panic(err) }
 		assert res.status() == .not_found
+		assert res.body == '404 on "${url}"'
 	}
 }
 
@@ -234,7 +236,6 @@ fn test_http_client_shutdown_does_not_work_without_a_cookie() {
 		return
 	}
 	assert x.status() == .not_found
-	assert x.body == '404 Not Found'
 }
 
 fn testsuite_end() {

vlib/vweb/tests/vweb_test_server.v

@@ -103,6 +103,12 @@ pub fn (mut app App) json() vweb.Result {
 	return app.ok(app.req.data)
 }
 
+// Custom 404 page
+pub fn (mut app App) not_found() vweb.Result {
+	app.set_status(404, 'Not Found')
+	return app.html('404 on "${app.req.url}"')
+}
+
 pub fn (mut app App) shutdown() vweb.Result {
 	session_key := app.get_cookie('skey') or { return app.not_found() }
 	if session_key != 'superman' {

vlib/vweb/vweb.v

@@ -740,7 +740,7 @@ fn handle_route[T](mut app T, url urllib.URL, routes &map[string]Route, tid int)
 		}
 	}
 	// Route not found
-	app.conn.write(vweb.http_404.bytes()) or {}
+	app.not_found()
 }
 
 // validate_middleware validates and fires all middlewares that are defined in the global app instance