Happy path 😸

Author: pcreux

Gemfile

@@ -4,3 +4,5 @@ source 'https://rubygems.org'
 gemspec
 
 gem 'rspec'
+gem 'guard-rspec'
+gem 'activemodel'

csv-importer.gemspec

@@ -23,6 +23,8 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.add_dependency "virtus"
+
   spec.add_development_dependency "bundler", "~> 1.8"
   spec.add_development_dependency "rake", "~> 10.0"
 end

lib/csv_importer.rb

@@ -1,5 +1,184 @@
 require "csv_importer/version"
+require "csv"
+require "virtus"
 
 module CSVImporter
-  # Your code goes here...
+  class CSVReader
+    include Virtus.model
+
+    attribute :content, String
+
+    def csv_rows
+      @csv_rows ||= CSV.parse(content)
+    end
+
+    def header
+      @header ||= csv_rows.first
+    end
+
+    def rows
+      @rows ||= csv_rows[1..-1]
+    end
+  end
+
+  class Column
+    include Virtus.model
+
+    attribute :name, Symbol
+    attribute :to
+    attribute :required, Boolean
+
+    def attribute
+      to || name
+    end
+  end
+
+  class Header
+    include Virtus.model
+
+    attribute :columns_config, Array[Column]
+    attribute :row, Array[String]
+
+    def columns
+      row.map(&:to_sym)
+    end
+  end
+
+  class Row
+    include Virtus.model
+
+    attribute :header, Header
+    attribute :row_array, Array[String]
+    attribute :model_klass
+
+    def model
+      @model ||= begin
+        model = model_klass.new
+        set_attributes(model)
+        model
+      end
+    end
+
+    def csv_attributes
+      @csv_attributes ||= Hash[header.columns.zip(row_array)]
+    end
+
+    def set_attributes(model)
+      header.columns_config.each do |column|
+        csv_value = csv_attributes[column.name]
+        attribute = column.attribute
+        if attribute.is_a?(Proc)
+          attribute.call(csv_value, model)
+        else
+          model.public_send("#{attribute}=", csv_value)
+        end
+      end
+    end
+  end
+
+  class Report
+    include Virtus.model
+
+    attribute :created_rows, Array[Row]
+    attribute :updated_rows, Array[Row]
+    attribute :failed_to_create_rows, Array[Row]
+    attribute :failed_to_update_rows, Array[Row]
+
+    def valid_rows
+      created_rows + updated_rows
+    end
+
+    def invalid_rows
+      failed_to_create_rows + failed_to_update_rows
+    end
+  end
+
+  class Runner
+    def self.call(*args)
+      new(*args).call
+    end
+
+    include Virtus.model
+
+    attribute :rows, Array[Row]
+
+    def call
+      report = Report.new
+
+      rows.each do |row|
+        if row.model.persisted?
+          if row.model.save
+            report.updated_rows << row
+          else
+            report.failed_to_update_rows << row
+          end
+        else
+          if row.model.save
+            report.created_rows << row
+          else
+            report.failed_to_create_rows << row
+          end
+        end
+      end
+
+      report
+    end
+  end
+
+  class Config
+    include Virtus.model
+
+    attribute :model
+    attribute :columns, Array[Column], default: proc { [] }
+    attribute :identifier, Symbol
+    attribute :when_invalid, Symbol, default: proc { :skip }
+  end
+
+  module Dsl
+    def model(model_klass)
+      csv_importer_config.model = model_klass
+    end
+
+    def column(name, options={})
+      csv_importer_config.columns << Column.new(options.merge(name: name))
+    end
+
+    def identifier(identifier)
+      csv_importer_config.identifier = identifier
+    end
+
+    def when_invalid(action)
+      csv_importer_config.when_invalid = action
+    end
+  end
+
+  def self.included(klass)
+    klass.extend(Dsl)
+    klass.define_singleton_method(:csv_importer_config) do
+      @csv_importer_config ||= Config.new
+    end
+  end
+
+  def initialize(*args)
+    @csv = CSVReader.new(*args)
+  end
+
+  attr_reader :csv, :report
+
+  def header
+    @header ||= Header.new(columns_config: config.columns, row: csv.header)
+  end
+
+  def config
+    self.class.csv_importer_config
+  end
+
+  def rows
+    csv.rows.map { |row_array| Row.new(header: header, row_array: row_array, model_klass: config.model) }
+  end
+
+  def run!
+    @report = Runner.call(rows: rows)
+  end
+
 end

spec/csv_importer_spec.rb

@@ -4,4 +4,78 @@
   it 'has a version number' do
     expect(CSVImporter::VERSION).not_to be nil
   end
+
+  class User
+    include Virtus.model
+    include ActiveModel::Model
+
+    attribute :email
+    attribute :f_name
+    attribute :l_name
+    attribute :confirmed_at
+
+    validates_presence_of :email
+    validates_format_of :email, with: /[^@]+@[^@]/ # contains one @ symbol
+
+    def valid?
+      email
+    end
+
+    def persisted?
+      @persisted ||= false
+    end
+
+    def save
+      @persisted = true
+    end
+  end
+
+  class ImportUserCSV
+    include CSVImporter
+
+    model User
+
+    column :email
+    column :first_name, to: :f_name
+    column :last_name,  to: :l_name
+    column :confirmed,  to: ->(confirmed, model) { model.confirmed_at = Time.new(2012) if confirmed == "true" }
+
+    identifier :email # will find_or_update via
+
+    when_invalid :skip # or :abort
+  end
+
+  CSV_CONTENT = "email,confirmed,first_name,last_name
+[email protected],true,bob,,"
+
+
+  it 'imports' do
+    import = ImportUserCSV.new(content: CSV_CONTENT)
+    expect(import.rows.size).to eq(1)
+
+    row = import.rows.first
+
+    expect(row.csv_attributes).to eq(
+      {
+        email: "[email protected]",
+        first_name: "bob",
+        last_name: nil,
+        confirmed: "true"
+      }
+    )
+
+    import.run!
+
+    expect(import.report.valid_rows.size).to eq(1)
+    expect(import.report.created_rows.size).to eq(1)
+
+    model = import.report.valid_rows.first.model
+    expect(model).to be_persisted
+    expect(model).to have_attributes(
+      email: "[email protected]",
+      f_name: "bob",
+      l_name: nil,
+      confirmed_at: Time.new(2012)
+    )
+  end
 end

spec/spec_helper.rb

@@ -1,2 +1,4 @@
 $LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
+require 'active_model'
+
 require 'csv_importer'