Better error messages for parsing bad input path, reference path, and…

… payload templates

lib/floe/workflow/catcher.rb

@@ -14,7 +14,7 @@ def initialize(_workflow, name, payload)
 
         @error_equals = payload["ErrorEquals"]
         @next         = payload["Next"]
-        @result_path  = ReferencePath.new(payload.fetch("ResultPath", "$"))
+        @result_path  = wrap_parser_error("ResultPath", payload.fetch("ResultPath", nil)) { ReferencePath.new(payload.fetch("ResultPath", "$")) }
 
         missing_field_error!("ErrorEquals") if !@error_equals.kind_of?(Array) || @error_equals.empty?
       end

lib/floe/workflow/choice_rule.rb

@@ -3,6 +3,8 @@
 module Floe
   class Workflow
     class ChoiceRule
+      include ValidationMixin
+
       class << self
         def build(workflow, name, payload)
           if (sub_payloads = payload["Not"])
@@ -33,7 +35,7 @@ def initialize(_workflow, name, payload, children = nil)
         @children  = children
 
         @next     = payload["Next"]
-        @variable = payload["Variable"]
+        @variable = wrap_parser_error("Variable", payload["Variable"]) { Path.new(payload["Variable"]) } if payload["Variable"]
       end
 
       def true?(*)
@@ -43,7 +45,7 @@ def true?(*)
       private
 
       def variable_value(context, input)
-        Path.value(variable, context, input)
+        variable.value(context, input)
       end
     end
   end

lib/floe/workflow/path.rb

@@ -36,6 +36,10 @@ def value(context, input = {})
         results = JsonPath.on(obj, path)
         results.count < 2 ? results.first : results
       end
+
+      def to_s
+        payload
+      end
     end
   end
 end

lib/floe/workflow/states/choice.rb

@@ -14,8 +14,8 @@ def initialize(workflow, name, payload)
           @choices = payload["Choices"].map.with_index { |choice, i| ChoiceRule.build(workflow, name + ["Choices", i.to_s], choice) }
           @default = payload["Default"]
 
-          @input_path  = Path.new(payload.fetch("InputPath", "$"))
-          @output_path = Path.new(payload.fetch("OutputPath", "$"))
+          @input_path  = wrap_parser_error("InputPath", payload.fetch("InputPath", nil)) { Path.new(payload.fetch("InputPath", "$")) }
+          @output_path = wrap_parser_error("OutputPath", payload.fetch("OutputPath", nil)) { Path.new(payload.fetch("OutputPath", "$")) }
         end
 
         def finish(context)

lib/floe/workflow/states/fail.rb

@@ -11,8 +11,8 @@ def initialize(workflow, name, payload)
 
           @cause      = payload["Cause"]
           @error      = payload["Error"]
-          @cause_path = Path.new(payload["CausePath"]) if payload["CausePath"]
-          @error_path = Path.new(payload["ErrorPath"]) if payload["ErrorPath"]
+          @cause_path = wrap_parser_error("CausePath", payload["CausePath"]) { Path.new(payload["CausePath"]) } if payload["CausePath"]
+          @error_path = wrap_parser_error("ErrorPath", payload["ErrorPath"]) { Path.new(payload["ErrorPath"]) } if payload["ErrorPath"]
         end
 
         def finish(context)

lib/floe/workflow/states/pass.rb

@@ -16,10 +16,10 @@ def initialize(workflow, name, payload)
           @end         = !!payload["End"]
           @result      = payload["Result"]
 
-          @parameters  = PayloadTemplate.new(payload["Parameters"]) if payload["Parameters"]
-          @input_path  = Path.new(payload.fetch("InputPath", "$"))
-          @output_path = Path.new(payload.fetch("OutputPath", "$"))
-          @result_path = ReferencePath.new(payload.fetch("ResultPath", "$"))
+          @parameters  = wrap_parser_error("Parameters", payload["Parameters"]) { PayloadTemplate.new(payload["Parameters"]) } if payload["Parameters"]
+          @input_path  = wrap_parser_error("InputPath", payload.fetch("InputPath", nil)) { Path.new(payload.fetch("InputPath", "$")) }
+          @output_path = wrap_parser_error("OutputPath", payload.fetch("OutputPath", nil)) { Path.new(payload.fetch("OutputPath", "$")) }
+          @result_path = wrap_parser_error("ResultPath", payload.fetch("ResultPath", nil)) { ReferencePath.new(payload.fetch("ResultPath", "$")) }
 
           validate_state!(workflow)
         end

lib/floe/workflow/states/succeed.rb

@@ -9,8 +9,8 @@ class Succeed < Floe::Workflow::State
         def initialize(workflow, name, payload)
           super
 
-          @input_path  = Path.new(payload.fetch("InputPath", "$"))
-          @output_path = Path.new(payload.fetch("OutputPath", "$"))
+          @input_path  = wrap_parser_error("InputPath", payload.fetch("InputPath", nil)) { Path.new(payload.fetch("InputPath", "$")) }
+          @output_path = wrap_parser_error("OutputPath", payload.fetch("OutputPath", nil)) { Path.new(payload.fetch("OutputPath", "$")) }
         end
 
         def finish(context)

lib/floe/workflow/states/task.rb

@@ -25,12 +25,12 @@ def initialize(workflow, name, payload)
           @timeout_seconds   = payload["TimeoutSeconds"]
           @retry             = payload["Retry"].to_a.map.with_index { |retrier, i| Retrier.new(workflow, name + ["Retry", i.to_s], retrier) }
           @catch             = payload["Catch"].to_a.map.with_index { |catcher, i| Catcher.new(workflow, name + ["Catch", i.to_s], catcher) }
-          @input_path        = Path.new(payload.fetch("InputPath", "$"))
-          @output_path       = Path.new(payload.fetch("OutputPath", "$"))
-          @result_path       = ReferencePath.new(payload.fetch("ResultPath", "$"))
-          @parameters        = PayloadTemplate.new(payload["Parameters"])     if payload["Parameters"]
-          @result_selector   = PayloadTemplate.new(payload["ResultSelector"]) if payload["ResultSelector"]
-          @credentials       = PayloadTemplate.new(payload["Credentials"])    if payload["Credentials"]
+          @input_path        = wrap_parser_error("InputPath", payload.fetch("InputPath", nil)) { Path.new(payload.fetch("InputPath", "$")) }
+          @output_path       = wrap_parser_error("OutputPath", payload.fetch("OutputPath", nil)) { Path.new(payload.fetch("OutputPath", "$")) }
+          @result_path       = wrap_parser_error("ResultPath", payload.fetch("ResultPath", nil)) { ReferencePath.new(payload.fetch("ResultPath", "$")) }
+          @parameters        = wrap_parser_error("Parameters", payload["Parameters"]) { PayloadTemplate.new(payload["Parameters"]) }             if payload["Parameters"]
+          @result_selector   = wrap_parser_error("ResultSelector", payload["ResultSelector"]) { PayloadTemplate.new(payload["ResultSelector"]) } if payload["ResultSelector"]
+          @credentials       = wrap_parser_error("Credentials", payload["Credentials"]) { PayloadTemplate.new(payload["Credentials"]) }          if payload["Credentials"]
 
           validate_state!(workflow)
         end

lib/floe/workflow/states/wait.rb

@@ -17,11 +17,10 @@ def initialize(workflow, name, payload)
           @end            = !!payload["End"]
           @seconds        = payload["Seconds"]&.to_i
           @timestamp      = payload["Timestamp"]
-          @timestamp_path = Path.new(payload["TimestampPath"]) if payload.key?("TimestampPath")
-          @seconds_path   = Path.new(payload["SecondsPath"]) if payload.key?("SecondsPath")
-
-          @input_path  = Path.new(payload.fetch("InputPath", "$"))
-          @output_path = Path.new(payload.fetch("OutputPath", "$"))
+          @timestamp_path = wrap_parser_error("TimestampPath", payload["TimestampPath"]) { Path.new(payload["TimestampPath"]) } if payload.key?("TimestampPath")
+          @seconds_path   = wrap_parser_error("SecondsPath", payload["SecondsPath"]) { Path.new(payload["SecondsPath"]) } if payload.key?("SecondsPath")
+          @input_path     = wrap_parser_error("InputPath", payload["InputPath"]) { Path.new(payload.fetch("InputPath", "$")) }
+          @output_path    = wrap_parser_error("OutputPath", payload["OutputPath"]) { Path.new(payload.fetch("OutputPath", "$")) }
 
           validate_state!(workflow)
         end

spec/workflow/states/pass_spec.rb

@@ -86,6 +86,20 @@
 
     #   it { expect { workflow }.to raise_error(Floe::InvalidWorkflowError, "States.PassState error") }
     # end
+
+    context "With an invalid Path" do
+      let(:payload) do
+        {
+          "PassState" => {
+            "Type"      => "Pass",
+            "InputPath" => "bad",
+            "End"       => true
+          }
+        }
+      end
+
+      it { expect { workflow }.to raise_error(Floe::InvalidWorkflowError, "States.PassState field \"InputPath\" value \"bad\" Path [bad] must start with \"$\"") }
+    end
   end
 
   describe "#end?" do