Add error handler for HTTP::Status and improve method definitions in DSL and Router

Author: sdogruyol

src/kemal/dsl.cr

@@ -12,7 +12,8 @@ HTTP_METHODS   = %w[get post put patch delete options]
 FILTER_METHODS = %w[get post put patch delete options all]
 
 # Defines a route for the given HTTP method.
-# The path must start with a `/`.
+#
+# NOTE: The path must start with a `/`.
 #
 # ```
 # get "/hello" do |env|
@@ -31,7 +32,8 @@ FILTER_METHODS = %w[get post put patch delete options all]
 {% end %}
 
 # Defines a WebSocket route.
-# The path must start with a `/`.
+#
+# NOTE: The path must start with a `/`.
 #
 # ```
 # ws "/chat" do |socket, env|
@@ -56,6 +58,17 @@ def error(status_code : Int32, &block : HTTP::Server::Context, Exception -> _)
   Kemal.config.add_error_handler status_code, &block
 end
 
+# Defines an error handler for the given `HTTP::Status`.
+#
+# ```
+# error :not_found do |env|
+#   "Page not found"
+# end
+# ```
+def error(status : HTTP::Status, &block : HTTP::Server::Context, Exception -> _)
+  Kemal.config.add_error_handler status.code, &block
+end
+
 # Defines an error handler for the given exception type.
 #
 # ```
@@ -93,7 +106,7 @@ end
      Kemal::FilterHandler::INSTANCE.{{ type.id }}({{ method }}.upcase, path, &block)
     end
 
-    def {{ type.id }}_{{ method.id }}(paths : Array(String), &block : HTTP::Server::Context -> _)
+    def {{ type.id }}_{{ method.id }}(paths : Enumerable(String), &block : HTTP::Server::Context -> _)
       paths.each do |path|
         Kemal::FilterHandler::INSTANCE.{{ type.id }}({{ method }}.upcase, path, &block)
       end
@@ -159,10 +172,13 @@ end
 # # Result: GET /users
 # ```
 def mount(router : Kemal::Router)
-  router.register_routes("")
+  router.register_routes
 end
 
-# Mounts a router at the given path prefix.
+# Mounts a router at the given *path* prefix.
+#
+# NOTE: The path must start with a `/`.
+#
 # All routes defined in the router will be prefixed with the given path.
 #
 # ```

src/kemal/router.cr

@@ -2,7 +2,7 @@ module Kemal
   # Router provides modular routing capabilities for Kemal applications.
   #
   # It allows grouping routes under a common prefix and applying filters
-  # to specific route groups. Routers can be nested using `namespace` or `group`.
+  # to specific route groups. Routers can be nested using `namespace`.
   #
   # ## Example
   #
@@ -68,7 +68,7 @@ module Kemal
     end
 
     # HTTP method helpers
-    {% for method in %w[get post put patch delete options] %}
+    {% for method in HTTP_METHODS %}
       # Defines a {{ method.id.upcase }} route.
       #
       # ```
@@ -117,7 +117,7 @@ module Kemal
     end
 
     # Method-specific before/after filters
-    {% for method in %w[get post put patch delete options all] %}
+    {% for method in FILTER_METHODS %}
       # Defines a before filter for {{ method.id.upcase }} requests.
       def before_{{ method.id }}(path : String = "*", &block : HTTP::Server::Context -> _)
         add_filter(:before, {{ method.upcase }}, path, &block)
@@ -129,7 +129,10 @@ module Kemal
       end
     {% end %}
 
-    # Creates a nested namespace/group with the given path prefix.
+    # Creates a nested namespace/group with the given *path* prefix.
+    #
+    # NOTE: The path must start with a `/`.
+    #
     # All routes defined inside the block will be prefixed with the given path.
     #
     # ```
@@ -149,7 +152,9 @@ module Kemal
       @sub_routers << SubRouter.new(path: path, router: sub_router)
     end
 
-    # Mounts another router at the given path prefix.
+    # Mounts another router at the given *path* prefix.
+    #
+    # NOTE: The path must start with a `/`.
     #
     # ```
     # users_router = Kemal::Router.new
@@ -207,7 +212,6 @@ module Kemal
     end
 
     # Collect all route paths including sub-routers
-    # :nodoc:
     protected def collect_all_route_paths(full_prefix : String) : Array(Tuple(String, String))
       paths = [] of Tuple(String, String)
 
@@ -248,7 +252,7 @@ module Kemal
 
         applicable_paths.each do |route_method, route_path|
           # Check if filter method matches route method
-          next unless filter.method == "ALL" || filter.method == route_method
+          next unless filter.method.in?("ALL", route_method)
 
           # Use filter's method (ALL or specific) when registering
           register_method = filter.method
@@ -284,8 +288,8 @@ module Kemal
     end
 
     private def join_paths(a : String, b : String) : String
-      a = a.chomp("/")
-      b = b.lchop("/") if b.starts_with?("/")
+      a = a.chomp('/')
+      b = b.lchop('/') if b.starts_with?('/')
       return "/#{b}" if a.empty?
       return a if b.empty?
       "#{a}/#{b}"