Add header record using Fixy and DryRB Validation gems

.rubocop.yml

@@ -3,15 +3,26 @@ require:
 
 AllCops:
   NewCops: enable
-  TargetRubyVersion: 2.6  
+  TargetRubyVersion: 2.7
+
+Layout/LineLength:
+  Max: 120
+
+Lint/MissingSuper:
+  Enabled: false
+
+Metrics/BlockLength:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
 
 Style/StringLiterals:
   Enabled: true
   EnforcedStyle: double_quotes
 
-Style/StringLiteralsInInterpolation:
-  Enabled: true
-  EnforcedStyle: double_quotes
+RSpec/ExampleLength:
+  Enabled: false
 
-Layout/LineLength:
-  Max: 120
+RSpec/MultipleExpectations:
+  Enabled: false

lib/mt9.rb

@@ -1,8 +1,23 @@
 # frozen_string_literal: true
 
-require_relative "mt9/version"
+require "dry-validation"
+require "fixy"
+
+require "mt9/values"
+require "mt9/validators/base_contract"
+require "mt9/validators/header_record_contract"
+require "mt9/base_record"
+require "mt9/header_record"
+require "mt9/version"
 
 module MT9
-  class Error < StandardError; end
-  # Your code goes here...
+  class ValidationError < StandardError
+    attr_reader :result
+
+    def initialize(result)
+      @result = result
+      errors = result.errors(full: true).messages
+      super("Validation failed: #{errors.join(', ')}")
+    end
+  end
 end

lib/mt9/base_record.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module MT9
+  class BaseRecord < Fixy::Record
+    include Fixy::Formatter::Alphanumeric
+
+    SPACE = " "
+
+    set_record_length 160
+  end
+end

lib/mt9/header_record.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module MT9
+  class HeaderRecord < BaseRecord
+    set_line_ending Fixy::Record::LINE_ENDING_CRLF
+
+    attr_reader :file_type, :account_number, :due_date, :client_short_name
+
+    field :file_type, 2, "1-2", :alphanumeric
+    field :account_number, 16, "3-18", :alphanumeric
+    field :due_date, 8, "19-26", :alphanumeric
+    field :filler5, 5, "27-31", :alphanumeric
+    field :client_short_name, 20, "32-51", :alphanumeric
+    field :filler109, 109, "52-160", :alphanumeric
+
+    field_value :filler5, SPACE * 5
+    field_value :filler109, SPACE * 109
+
+    def initialize(...)
+      validator = Validators::HeaderRecordContract.new
+      result = validator.call(...)
+      raise MT9::ValidationError, result unless result.success?
+
+      result.to_h.each do |key, value|
+        instance_variable_set("@#{key}", value)
+      end
+    end
+  end
+end

lib/mt9/validators/base_contract.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module MT9
+  module Validators
+    class BaseContract < Dry::Validation::Contract
+      register_macro(:is_account_number?) do
+        key.failure("must be 15 or 16 numeric characters") unless /^(\d{15}|\d{16})$/.match(value)
+        key.failure("must not start with a reserved bank code") if value.start_with?(*MT9::Values::RESERVED_BANK_CODES)
+      end
+    end
+  end
+end

lib/mt9/validators/header_record_contract.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module MT9
+  module Validators
+    class HeaderRecordContract < BaseContract
+      schema do
+        required(:file_type).filled(:string, included_in?: MT9::Values::FILE_TYPES)
+        required(:account_number).filled(:string)
+        required(:due_date).filled(:string)
+        optional(:client_short_name).value(:string, size?: 0..20)
+      end
+
+      rule(:account_number).validate(:is_account_number?)
+
+      rule(:due_date) do
+        key.failure("must be 6 or 8 numeric characters") unless /^(\d{6}|\d{8})$/.match(value)
+      end
+    end
+  end
+end

lib/mt9/values.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module MT9
+  module Values
+    RESERVED_BANK_CODES = %w[99].freeze
+
+    DIRECT_CREDIT = "12"
+    DIRECT_DEBIT = "20"
+    FILE_TYPES = [DIRECT_CREDIT, DIRECT_DEBIT].freeze
+  end
+end

mt9.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
     "MT9 is a data standard used within the NZ banking industry for the creation of Bulk Payments and Receipts."
   spec.homepage = "https://github.com/zeptofs/mt9"
   spec.license = "MIT"
-  spec.required_ruby_version = ">= 2.6.0"
+  spec.required_ruby_version = ">= 2.7.0"
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
@@ -25,9 +25,10 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  # Uncomment to register a new dependency of your gem
-  # spec.add_dependency "example-gem", "~> 1.0"
+  spec.add_dependency "dry-validation", "~> 1.8.0"
+  spec.add_dependency "fixy", "~> 0.0.9"
 
+  spec.add_development_dependency "pry-byebug", "~> 3.9.0"
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html
   spec.metadata["rubygems_mfa_required"] = "true"

spec/fixtures/mt9_direct_credits.txt

@@ -0,0 +1,4 @@
+12123113000631400 071020       asbd 2                                                                                                                           
+13123113000214500 0510000000102PayeeName 0         000000000000Payeecde0   PayeeRef0   PayeePrt0    PayerName           Payercde    PayerRef    PayerPrt        
+13123113000214500 0510000000201PayeeName 1         000000000000Payeecde1   PayeeRef1   PayeePrt1    PayerName           Payercde    PayerRef    PayerPrt        
+139962260004290             303                                                                                                                                 

spec/fixtures/mt9_direct_debits.txt

@@ -0,0 +1,5 @@
+20123113000214500 031121       test co                                                                                                                          
+13123009000012300 0000000000100PayerName 0         000000000000Payercde0   PayerRef0   PayerPrt0    PayeeName           Payeecde    PayeeRef    PayeePrt        
+13123009000012300 0000000000200PayerName 1         000000000000Payercde1   PayerRef1   PayerPrt1    PayeeName           Payeecde    PayeeRef    PayeePrt        
+13123009000012300 0000000000300PayerName 2         000000000000Payercde2   PayerRef2   PayerPrt2    PayeeName           Payeecde    PayeeRef    PayeePrt        
+139990270000369             600                                                                                                                                 

spec/mt9/header_record_spec.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+RSpec.describe MT9::HeaderRecord do
+  let(:header_record) do
+    {
+      file_type: "12",
+      account_number: "123456789012345",
+      due_date: "251220",
+      client_short_name: "ACME Pty Ltd"
+    }
+  end
+
+  describe "when generating header record" do
+    subject(:result) { described_class.new(**header_record).generate }
+
+    it "creates correctly formatted string" do
+      expect(result).to eq("12123456789012345 251220       ACME Pty Ltd                                                                                                                     \r\n") # rubocop:disable Layout/LineLength
+    end
+
+    it "creates correctly formatted string with a long account number and due date" do
+      header_record[:account_number] = "1234567890123456"
+      header_record[:due_date] = "25122020"
+
+      expect(result).to eq("12123456789012345625122020     ACME Pty Ltd                                                                                                                     \r\n") # rubocop:disable Layout/LineLength
+    end
+  end
+
+  it "raises ValidationError with an incorrect header record" do
+    header_record[:file_type] = "999"
+
+    expect { described_class.new(**header_record) }.to \
+      raise_error(MT9::ValidationError, "Validation failed: file_type must be one of: 12, 20")
+  end
+end

spec/mt9/validators/header_record_contract_spec.rb

@@ -0,0 +1,80 @@
+# frozen_string_literal: true
+
+RSpec.describe MT9::Validators::HeaderRecordContract do
+  subject(:result) { described_class.new.call(header_record) }
+
+  let(:header_record) do
+    {
+      file_type: "12",
+      account_number: "123456789012345",
+      due_date: "120321",
+      client_short_name: "ACME Pty Ltd"
+    }
+  end
+
+  it "validates a correct header record" do
+    expect(result).to be_success
+  end
+
+  it "validates with a 16 digit account number" do
+    header_record[:account_number] = "1234567890123456"
+    expect(result).to be_success
+  end
+
+  it "validates with a 8 digit due date" do
+    header_record[:due_date] = "12032021"
+    expect(result).to be_success
+  end
+
+  it "validates a correct header record with no client short name" do
+    header_record.delete(:client_short_name)
+    expect(result).to be_success
+  end
+
+  describe "with an incorrect header record" do
+    it "validates an invalid file type" do
+      header_record[:file_type] = "999"
+      expect(result.errors[:file_type]).to eq(["must be one of: 12, 20"])
+    end
+
+    it "validates a reserved bank code" do
+      header_record[:account_number] = "991234567890123"
+      expect(result.errors[:account_number]).to eq(["must not start with a reserved bank code"])
+    end
+
+    it "validates a short account number" do
+      header_record[:account_number] = "123456790"
+      expect(result.errors[:account_number]).to eq(["must be 15 or 16 numeric characters"])
+    end
+
+    it "validates a long account number" do
+      header_record[:account_number] = "12345678901234567"
+      expect(result.errors[:account_number]).to eq(["must be 15 or 16 numeric characters"])
+    end
+
+    it "validates a short due date" do
+      header_record[:due_date] = "213"
+      expect(result.errors[:due_date]).to eq(["must be 6 or 8 numeric characters"])
+    end
+
+    it "validates a 7 digit due date" do
+      header_record[:due_date] = "1234567"
+      expect(result.errors[:due_date]).to eq(["must be 6 or 8 numeric characters"])
+    end
+
+    it "validates a long due date" do
+      header_record[:due_date] = "202105114"
+      expect(result.errors[:due_date]).to eq(["must be 6 or 8 numeric characters"])
+    end
+
+    it "validates a long client short name" do
+      header_record[:client_short_name] = "ACME Transactions and Payments Proprietary Limited"
+      expect(result.errors[:client_short_name]).to eq(["length must be within 0 - 20"])
+    end
+
+    it "validates a nil client short name" do
+      header_record[:client_short_name] = nil
+      expect(result.errors[:client_short_name]).to eq(["must be a string"])
+    end
+  end
+end

spec/spec_helper.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "mt9"
+require "pry-byebug"
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure