[WIP] Schema validator

lib/jsonapi_parameters.rb

@@ -1,6 +1,6 @@
 require 'jsonapi_parameters/parameters'
 require 'jsonapi_parameters/handlers'
-require 'jsonapi_parameters/validator'
+require 'jsonapi_parameters/schema_validator'
 require 'jsonapi_parameters/translator'
 require 'jsonapi_parameters/core_ext'
 require 'jsonapi_parameters/stack_limit'

lib/jsonapi_parameters/schema_validator.rb

@@ -0,0 +1,51 @@
+require 'json_schemer'
+
+module JsonApi::Parameters
+  SCHEMA_PATH = Pathname.new(__dir__).join('jsonapi_schema.json').to_s.freeze
+
+  private
+
+  def should_prevalidate?
+    JsonApi::Parameters.enforce_schema_prevalidation && !JsonApi::Parameters.suppress_schema_validation_errors
+  end
+
+  class SchemaValidator
+    class ValidationError < StandardError; end
+
+    def initialize(payload)
+      @payload = payload.deep_stringify_keys
+    end
+
+    attr_reader :payload
+
+    def validate!
+      schema = JSONSchemer.schema(File.read(SCHEMA_PATH))
+
+      unless schema.valid?(payload) # rubocop:disable Style/GuardClause
+        errors = []
+
+        schema.validate(payload).each do |validation_error|
+          errors << nice_error(validation_error)
+        end
+
+        raise SchemaValidator::ValidationError.new(errors.join(', '))
+      end
+    end
+
+    private
+
+    # Based on & thanks to https://polythematik.de/2020/02/17/ruby-json-schema/
+    def nice_error(err)
+      case err['type']
+      when 'required'
+        "path '#{err['data_pointer']}' is missing keys: #{err['details']['missing_keys'].join ', '}"
+      when 'format'
+        "path '#{err['data_pointer']}' is not in required format (#{err['schema']['format']})"
+      when 'minLength'
+        "path '#{err['data_pointer']}' is not long enough (min #{err['schema']['minLength']})"
+      else
+        "path '#{err['data_pointer']}' is invalid according to the JsonApi schema"
+      end
+    end
+  end
+end

lib/jsonapi_parameters/translator.rb

@@ -18,12 +18,12 @@ def jsonapi_translate(params, naming_convention:)
 
     @jsonapi_unsafe_hash = ensure_naming(params, naming_convention)
 
-    JsonApi::Parameters::Validator.new(@jsonapi_unsafe_hash.deep_dup).validate! if should_prevalidate?
+    JsonApi::Parameters::SchemaValidator.new(@jsonapi_unsafe_hash.deep_dup).validate! if should_prevalidate?
 
     formed_parameters
   rescue StandardError => err
     # Validate the payload and raise errors...
-    JsonApi::Parameters::Validator.new(@jsonapi_unsafe_hash.deep_dup).validate! unless JsonApi::Parameters.suppress_schema_validation_errors
+    JsonApi::Parameters::SchemaValidator.new(@jsonapi_unsafe_hash.deep_dup).validate! unless JsonApi::Parameters.suppress_schema_validation_errors
 
     raise err # ... or if there were none, re-raise initial error
   end

spec/lib/jsonapi_parameters/validator_spec.rb

@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe JsonApi::Parameters::Validator do # rubocop:disable RSpec/FilePath
+describe JsonApi::Parameters::SchemaValidator do # rubocop:disable RSpec/FilePath
   describe 'initializer' do
     it 'ensures @payload has keys deeply stringified' do
       validator = described_class.new(payload: { sample: 'value' })
@@ -26,7 +26,7 @@ class Translator
         it 'raises validation errors' do
           payload = { payload: { sample: 'value' } }
 
-          expect { translator.jsonapify(payload) }.to raise_error(ActiveModel::ValidationError)
+          expect { translator.jsonapify(payload) }.to raise_error(JsonApi::Parameters::SchemaValidator::ValidationError)
         end
 
         it 'does not raise TranslatorError' do
@@ -42,7 +42,7 @@ class Translator
 
           begin
             translator.jsonapify(payload)
-          rescue ActiveModel::ValidationError => _ # rubocop:disable Lint/HandleExceptions
+          rescue JsonApi::Parameters::SchemaValidator::ValidationError => _ # rubocop:disable Lint/HandleExceptions
           end
         end
       end
@@ -55,7 +55,7 @@ class Translator
         it 'does not raise validation errors' do
           payload = { payload: { sample: 'value' } }
 
-          expect { translator.jsonapify(payload) }.not_to raise_error(ActiveModel::ValidationError)
+          expect { translator.jsonapify(payload) }.not_to raise_error(JsonApi::Parameters::SchemaValidator::ValidationError)
         end
 
         it 'still raises any other errors' do
@@ -77,7 +77,7 @@ class Translator
         it 'raises validation errors' do
           payload = { payload: { sample: 'value' } }
 
-          expect { translator.jsonapify(payload) }.to raise_error(ActiveModel::ValidationError)
+          expect { translator.jsonapify(payload) }.to raise_error(JsonApi::Parameters::SchemaValidator::ValidationError)
         end
       end
 
@@ -88,7 +88,7 @@ class Translator
         expect(File).to receive(:read).with(JsonApi::Parameters::SCHEMA_PATH).and_call_original
         expect(JSONSchemer).to receive(:schema).and_call_original
 
-        expect { validator.validate! }.to raise_error(ActiveModel::ValidationError)
+        expect { validator.validate! }.to raise_error(JsonApi::Parameters::SchemaValidator::ValidationError)
       end
     end
 
@@ -98,11 +98,11 @@ class Translator
         payload = { controller: 'examples_controller', action: 'create', commit: 'Sign up' }
         validator = described_class.new(payload)
 
-        expect { validator.validate! }.to raise_error(ActiveModel::ValidationError)
+        expect { validator.validate! }.to raise_error(JsonApi::Parameters::SchemaValidator::ValidationError)
 
         begin
           validator.validate!
-        rescue ActiveModel::ValidationError => err
+        rescue JsonApi::Parameters::SchemaValidator::ValidationError => err
           rails_specific_params.each do |param|
             expect(err.message).not_to include("Payload path '/#{param}'")
           end