From c790c574155265121c12d79d1b63c116a652be85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Guitaut?= <loic@discourse.org>
Date: Thu, 13 Jun 2024 11:55:57 +0200
Subject: [PATCH] DEV: Show parameters on a service contract failure

Now, when calling `StepsInspector#error` on a contract failure, the
output will contain the parameters provided to the contract.
---
 app/services/service/base.rb     | 6 +++++-
 lib/steps_inspector.rb           | 2 +-
 spec/lib/steps_inspector_spec.rb | 4 ++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/app/services/service/base.rb b/app/services/service/base.rb
index 6c8f608b7fe..531169f44cd 100644
--- a/app/services/service/base.rb
+++ b/app/services/service/base.rb
@@ -177,7 +177,7 @@ module Service
         context[contract_name] = contract
         context[result_key] = Context.build
         if contract.invalid?
-          context[result_key].fail(errors: contract.errors)
+          context[result_key].fail(errors: contract.errors, parameters: contract.raw_attributes)
           context.fail!
         end
       end
@@ -218,6 +218,10 @@ module Service
           include ActiveModel::Attributes
           include ActiveModel::AttributeMethods
           include ActiveModel::Validations::Callbacks
+
+          def raw_attributes
+            @attributes.values_before_type_cast
+          end
         end
     end
 
diff --git a/lib/steps_inspector.rb b/lib/steps_inspector.rb
index 80b5438563d..61f71a830d5 100644
--- a/lib/steps_inspector.rb
+++ b/lib/steps_inspector.rb
@@ -73,7 +73,7 @@ class StepsInspector
   # @!visibility private
   class Contract < Step
     def error
-      step_result.errors.inspect
+      "#{step_result.errors.inspect}\n\nProvided parameters: #{step_result.parameters.pretty_inspect}"
     end
   end
 
diff --git a/spec/lib/steps_inspector_spec.rb b/spec/lib/steps_inspector_spec.rb
index 534d0356140..38227239a7d 100644
--- a/spec/lib/steps_inspector_spec.rb
+++ b/spec/lib/steps_inspector_spec.rb
@@ -219,6 +219,10 @@ RSpec.describe StepsInspector do
       it "returns an error related to the contract" do
         expect(error).to match(/ActiveModel::Error attribute=parameter, type=blank, options={}/)
       end
+
+      it "returns the provided paramaters" do
+        expect(error).to match(/{"parameter"=>nil}/)
+      end
     end
 
     context "when the policy step is failing" do