Show full route constraints in error message

When an optimized helper fails to generate, show the full route constraints
in the error message. Previously it would only show the contraints that were
required as part of the path.

Fixes #13592

actionpack/CHANGELOG.md

@@ -1,3 +1,13 @@
+*   Show full route constraints in error message
+
+    When an optimized helper fails to generate, show the full route constraints
+    in the error message. Previously it would only show the contraints that were
+    required as part of the path.
+
+    Fixes #13592
+
+    *Andrew White*
+
 *   Use a custom route visitor for optimized url generation. Fixes #13349.
 
     *Andrew White*

actionpack/lib/action_dispatch/journey/formatter.rb

@@ -33,8 +33,8 @@ def generate(type, name, options, recall = {}, parameterize = nil)
           return [route.format(parameterized_parts), params]
         end
 
-        message = "No route matches #{constraints.inspect}"
-        message << " missing required keys: #{missing_keys.inspect}" if name
+        message = "No route matches #{Hash[constraints.sort].inspect}"
+        message << " missing required keys: #{missing_keys.sort.inspect}" if name
 
         raise ActionController::UrlGenerationError, message
       end

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -210,8 +210,9 @@ def missing_keys(args)
             end
 
             def raise_generation_error(args, missing_keys)
-              message = "No route matches #{args.inspect}"
-              message << " missing required keys: #{missing_keys.inspect}"
+              constraints = Hash[@route.requirements.merge(args).sort]
+              message = "No route matches #{constraints.inspect}"
+              message << " missing required keys: #{missing_keys.sort.inspect}"
 
               raise ActionController::UrlGenerationError, message
             end

actionpack/test/dispatch/routing_test.rb

@@ -3708,3 +3708,28 @@ def test_redirect_doesnt_match_unnamed_route
     end
   end
 end
+
+class TestUrlGenerationErrors < ActionDispatch::IntegrationTest
+  Routes = ActionDispatch::Routing::RouteSet.new.tap do |app|
+    app.draw do
+      get "/products/:id" => 'products#show', :as => :product
+    end
+  end
+
+  def app; Routes end
+
+  include Routes.url_helpers
+
+  test "url helpers raise a helpful error message whem generation fails" do
+    url, missing = { action: 'show', controller: 'products', id: nil }, [:id]
+    message = "No route matches #{url.inspect} missing required keys: #{missing.inspect}"
+
+    # Optimized url helper
+    error = assert_raises(ActionController::UrlGenerationError){ product_path(nil) }
+    assert_equal message, error.message
+
+    # Non-optimized url helper
+    error = assert_raises(ActionController::UrlGenerationError, message){ product_path(id: nil) }
+    assert_equal message, error.message
+  end
+end