Reworked error handling and pipeline functionality

examples/errorpages.ru

@@ -8,19 +8,58 @@ app = Landline::Server.new do
     header "content-type", "text/plain"
     "Hello World!"
   end
-  get "/error" do
+
+  get "/error" do # This error will be caught by the default server handler
     raise StandardError, "I raised an error! (and that's very sad)"
   end
-  handle do |status, backtrace: nil|
+
-    page = ([Landline::Util::HTTP_STATUS[status]] +
+  path "/handled" do
-            (backtrace || [""])).join("\n")
+    get "/error" do # This error will be caught by the handler defined for this path
-    [
+      raise StandardError, "I raised an error! (and that's very sad)"
-      {
+    end
-        "content-length": page.bytesize,
+
-        "content-type": "text/plain"
+    handle do |status, backtrace: nil, error: nil|
-      },
+      ([Landline::Util::HTTP_STATUS[status]] +
-      page
+      (backtrace || [""])).join("\n")
-    ]
+    end
+  end
+
+  path "/pipelined" do
+    # The pipeline executes inside the function which catches errors,
+    # so it can catch errors before the handler for the current path.
+    # This may be useful in order to override the way things are output.
+    pipeline do |request, &output|
+      output.call(request)
+    rescue StandardError
+      throw :finish, "Internal error caught in pipeline!"
+    end
+
+    path "/inner" do
+      get "/error" do # This error will be caught by the pipeline
+        raise StandardError, "I raised an error! (and that's very sad)"
+      end
+    end
+
+    path "/inner_override" do
+      get "/error" do # This error will be caught by the innermost handler
+        raise StandardError, "I raised an error! (and that's very sad)"
+      end
+
+      handle do |status, backtrace: nil, error: nil|
+        ([Landline::Util::HTTP_STATUS[status]] +
+        (backtrace || [""])).join("\n")
+      end
+    end
+
+    get "/error" do # This error will be caught by the pipeline
+      raise StandardError, "I raised an error! (and that's very sad)"
+    end
+
+    # This handler is preceded by the pipeline, but it may handle 404 codes.
+    handle do |status, backtrace: nil, error: nil|
+      ([Landline::Util::HTTP_STATUS[status]] +
+      (backtrace || [""])).join("\n")
+    end
   end
 end
 

examples/rack_app.ru

@@ -27,6 +27,7 @@ class HelloServer < Landline::App
     page = ([Landline::Util::HTTP_STATUS[status]] +
             (backtrace || [""])).join("\n")
     [
+      status,
       {
         "content-length": page.bytesize,
         "content-type": "text/plain",

lib/landline/dsl/methods_common.rb

@@ -9,14 +9,17 @@ module Landline
       # @param errorcode [Integer]
       # @param backtrace [Array(String), nil]
       # @raise [UncaughtThrowError] throws :finish to return back to Server
-      def die(errorcode, backtrace: nil)
+      def die(errorcode, backtrace: nil, error: nil)
-        throw :finish, [errorcode].append(
+        response = Landline::Response.convert(
-          *(@origin.properties["handle.#{errorcode}"] or
+          (@origin.properties["handle.#{errorcode}"] or
-            @origin.properties["handle.default"]).call(
+           @origin.properties["handle.default"]).call(
-              errorcode,
+             errorcode,
-              backtrace: backtrace
+             backtrace: backtrace,
-            )
+             error: error
+           )
         )
+        response.status = errorcode if response.status == 200
+        throw :finish, response
       end
 
       # (in Landline::Probe context)

lib/landline/path.rb

@@ -37,6 +37,24 @@ module Landline
       context.instance_exec(&setup)
     end
 
+    # (see ::Landline::Node#go)
+    def go(request)
+      # This is done to allow pipeline to interject handlers
+      # I'm more than willing to admit that this is stupid,
+      # but it is well worth the logical flexibility.
+      if ['handle.default', 'handle.505'].any? do |x|
+           @properties.storage.include? x
+         end
+        begin
+          super(request)
+        rescue StandardError => e
+          _die(request, 500, backtrace: [e.to_s] + e.backtrace, error: e)
+        end
+      else
+        super(request)
+      end
+    end
+
     # Method callback on successful request navigation.
     # Finds the next appropriate path to go to.
     # @return [Boolean] true if further navigation will be done
@@ -138,8 +156,6 @@ module Landline
       return exit_stack(request, value) if value
 
       notfound(request)
-    rescue StandardError => e
-      _die(request, 500, backtrace: [e.to_s] + e.backtrace)
     end
 
     # Run enqueued postprocessors on navigation failure
@@ -175,16 +191,19 @@ module Landline
     # @param errorcode [Integer]
     # @param backtrace [Array(String), nil]
     # @raise [UncaughtThrowError] throws :finish to stop processing
-    def _die(request, errorcode, backtrace: nil)
+    def _die(request, errorcode, backtrace: nil, error: nil)
       proccontext = get_context(request)
-      throw :finish, [errorcode].append(
+      response = Landline::Response.convert(
-        *proccontext.instance_exec(
+        proccontext.instance_exec(
           errorcode,
           backtrace: backtrace,
+          error: error,
           &(@properties["handle.#{errorcode}"] or
             @properties["handle.default"])
         )
       )
+      response.status = errorcode if response.status == 200
+      throw :finish, response
     end
   end
 end

lib/landline/pattern_matching.rb

@@ -35,7 +35,7 @@ module Landline
     def match(input)
       if @pattern.is_a? String
         input = Landline::PatternMatching.canonicalize(input)
-        if input.start_with?(@pattern)
+        if _match?(input)
           [input.delete_prefix(@pattern), [], {}]
         else
           false
@@ -51,7 +51,8 @@ module Landline
     # @return [Boolean]
     def match?(input)
       if @pattern.is_a? String
-        Landline::PatternMatching.canonicalize(input).start_with? @pattern
+        input = Landline::PatternMatching.canonicalize(input)
+        _match?(input)
       else
         @pattern.match?(input)
       end
@@ -59,6 +60,13 @@ module Landline
 
     private
 
+    def _match?(input)
+      parts = input.split("/")
+      @pattern.split("/").map.with_index do |part, index|
+        parts[index] == part
+      end.all?(true)
+    end
+
     def patternify(pattern)
       classdomain = Landline::PatternMatching
       classdomain.constants

lib/landline/server.rb

@@ -58,14 +58,14 @@ module Landline
     def setup_properties(*_args, **_opts)
       {
         "index" => [],
-        "handle.default" => proc do |code, backtrace: nil|
+        "handle.default" => proc do |code, backtrace: nil, **_extra|
           page = Landline::Util.default_error_page(code, backtrace)
           headers = {
             "content-length": page.bytesize,
             "content-type": "text/html",
             "x-cascade": true
           }
-          [headers, page]
+          [code, headers, page]
         end,
         "path" => "/"
       }.each { |k, v| @properties[k] = v unless @properties[k] }

lib/landline/util/lookup.rb

@@ -31,7 +31,7 @@ module Landline
         @storage[key] = value
       end
 
-      attr_accessor :parent
+      attr_accessor :parent, :storage
     end
 
     # Read-only lookup proxy