Added cleaner error messages to help migration (#82)

* Added cleaner error messages to help migration

Author: thexa4

README.md

@@ -64,7 +64,7 @@ class Venue
     'mydomain'
   end
 
-  media_type 'venue'
+  use_name 'venue'
 
   validations do
     version 2 do

lib/media_types/dsl.rb

@@ -47,7 +47,9 @@ def validate_unsafe!(output, media_type = to_constructable, **opts)
       def validatable?(media_type = to_constructable)
         return false unless validations
 
-        validations.find(media_type, -> { nil })
+        resolved = validations.find(media_type, -> { nil })
+
+        !resolved.nil?
       end
 
       def register
@@ -112,7 +114,10 @@ def use_name(name)
       end
 
       def validations(&block)
-        return media_type_validations unless block_given?
+        unless block_given?
+          raise 'No validations defined' if media_type_validations.nil?
+          return media_type_validations
+        end
         self.media_type_validations = Validations.new(to_constructable, &block)
 
         self

lib/media_types/scheme.rb

@@ -101,6 +101,7 @@ def valid?(output, **opts)
     #
     def validate(output, options = nil, **opts)
       options ||= ValidationOptions.new(**opts)
+      options.context = output
 
       catch(:end) do
         validate!(output, options, context: nil)

lib/media_types/scheme/missing_validation.rb

@@ -9,18 +9,21 @@ class MissingValidation
       def validate!(_output, options, context:, **_opts)
         # Check that no unknown keys are present
         return true unless options.strict
-        raise_strict!(key: context.key, strict_keys: context.rules, backtrace: options.backtrace)
+        raise_strict!(key: context.key, strict_keys: context.rules, backtrace: options.backtrace, found: options.scoped_output)
       end
 
-      def raise_strict!(key:, backtrace:, strict_keys:)
+      def raise_strict!(key:, backtrace:, strict_keys:, found:)
         raise StrictValidationError, format(
           "Unknown key %<key>s in data.\n" \
           "\tFound at: %<backtrace>s\n" \
           "\tExpected:\n\n" \
-          '%<strict_keys>s',
+          "%<strict_keys>s\n\n" \
+          "\tBut I Found:\n\n" \
+          '%<found>s',
           key: key.inspect,
           backtrace: backtrace.join('->'),
-          strict_keys: strict_keys.inspect(1)
+          strict_keys: strict_keys.keys,
+          found: (found.is_a? Hash) ? found.keys : found.class.name
         )
       end
 

lib/media_types/scheme/output_empty_guard.rb

@@ -21,7 +21,7 @@ def initialize(output, options, rules:)
       def call
         return unless MediaTypes::Object.new(output).empty?
         throw(:end, true) if allow_empty?
-        raise_empty!(backtrace: options.backtrace)
+        raise_empty!(backtrace: options.backtrace, found: options.scoped_output)
       end
 
       private
@@ -32,11 +32,12 @@ def allow_empty?
         rules.allow_empty? || rules.required.empty?
       end
 
-      def raise_empty!(backtrace:)
+      def raise_empty!(backtrace:, found:)
         raise EmptyOutputError, format(
-          'Expected output, got empty at %<backtrace>s. Required are: %<required>s.',
+          'Expected output, got empty at %<backtrace>s. Required are: %<required>s. Found: %<found>s',
           backtrace: backtrace.join('->'),
-          required: rules.required.keys
+          required: rules.required.keys,
+          found: (found.is_a? Hash) ? found.keys : found.class.name,
         )
       end
     end

lib/media_types/scheme/rules_exhausted_guard.rb

@@ -31,7 +31,7 @@ def call
         result = iterate(->(key) { required_rules.remove(key) })
         return result if required_rules.empty?
 
-        raise_exhausted!(missing_keys: required_rules.keys, backtrace: options.backtrace)
+        raise_exhausted!(missing_keys: required_rules.keys, backtrace: options.backtrace, found: output)
       end
 
       def iterate(mark)
@@ -50,11 +50,12 @@ def iterate(mark)
 
       attr_accessor :rules, :options, :output
 
-      def raise_exhausted!(missing_keys:, backtrace:)
+      def raise_exhausted!(missing_keys:, backtrace:, found:)
         raise ExhaustedOutputError, format(
-          'Missing keys in output: %<missing_keys>s at [%<backtrace>s]',
+          'Missing keys in output: %<missing_keys>s at [%<backtrace>s]. I did find: %<found>s',
           missing_keys: missing_keys,
-          backtrace: backtrace.join('->')
+          backtrace: backtrace.join('->'),
+          found: (found.is_a? Hash) ? found.keys : found.class.name,
         )
       end
     end

lib/media_types/scheme/validation_options.rb

@@ -3,28 +3,39 @@
 module MediaTypes
   class Scheme
     class ValidationOptions
-      attr_accessor :exhaustive, :strict, :backtrace
+      attr_accessor :exhaustive, :strict, :backtrace, :context
 
-      def initialize(exhaustive: true, strict: true, backtrace: [])
+      def initialize(context = {}, exhaustive: true, strict: true, backtrace: [])
         self.exhaustive = exhaustive
         self.strict = strict
         self.backtrace = backtrace
+        self.context = context
       end
 
       def inspect
-        "backtrack: #{backtrace.inspect}, strict: #{strict.inspect}, exhaustive: #{exhaustive}"
+        "backtrack: #{backtrace.inspect}, strict: #{strict.inspect}, exhaustive: #{exhaustive}, current_obj: #{scoped_output.to_json}"
+      end
+
+      def scoped_output
+        current = context
+
+        backtrace.drop(1).first([0, backtrace.size - 2].max).each do |e|
+          current = current[e] unless current.nil?
+        end
+
+        current
       end
 
       def with_backtrace(backtrace)
-        ValidationOptions.new(exhaustive: exhaustive, strict: strict, backtrace: backtrace)
+        ValidationOptions.new(context, exhaustive: exhaustive, strict: strict, backtrace: backtrace)
       end
 
       def trace(*traces)
         with_backtrace(backtrace.dup.concat(traces))
       end
 
       def exhaustive!
-        ValidationOptions.new(exhaustive: true, strict: strict, backtrace: backtrace)
+        ValidationOptions.new(context, exhaustive: true, strict: strict, backtrace: backtrace)
       end
     end
   end

lib/media_types/validations.rb

@@ -46,6 +46,7 @@ def find(media_type, default = -> { Scheme.new(allow_empty: true) { not_strict }
 
     def method_missing(method_name, *arguments, &block)
       if scheme.respond_to?(method_name)
+        media_type.__getobj__.media_type_combinations ||= Set.new
         media_type.__getobj__.media_type_combinations.add(media_type.as_key)
 
         return scheme.send(method_name, *arguments, &block)

test/media_types/validations_test.rb

@@ -18,7 +18,9 @@ def self.organisation
     end
 
     def test_it_is_not_validatable
-      refute TestSchemeType.validatable?
+      assert_raises RuntimeError do
+        TestSchemeType.validatable?
+      end
     end
   end
 end