Create a dev:populate task to add fake data to your dev environment

Gemfile

@@ -125,16 +125,21 @@ group :development do
   gem "better_errors"
   gem "binding_of_caller"
   gem "debug_inspector"
+  gem "faker"
   gem "listen"
+  gem "timecop"
   gem "vendorer"
 end
 
+group :development, :test do
+  gem "factory_bot_rails"
+end
+
 # Gems needed for running tests
 group :test do
   gem "brakeman"
   gem "capybara", ">= 2.15"
   gem "erb_lint", :require => false
-  gem "factory_bot_rails"
   gem "minitest", "~> 5.1"
   gem "puma", "~> 5.0"
   gem "rails-controller-testing"

Gemfile.lock

@@ -197,6 +197,8 @@ GEM
     factory_bot_rails (6.1.0)
       factory_bot (~> 6.1.0)
       railties (>= 5.0.0)
+    faker (2.16.0)
+      i18n (>= 1.6, < 2)
     faraday (1.4.1)
       faraday-excon (~> 1.1)
       faraday-net_http (~> 1.0)
@@ -448,6 +450,7 @@ GEM
     thor (1.1.0)
     thread_safe (0.3.6)
     tilt (2.0.10)
+    timecop (0.9.4)
     tzinfo (1.2.9)
       thread_safe (~> 0.1)
     uglifier (4.2.0)
@@ -496,6 +499,7 @@ DEPENDENCIES
   delayed_job_active_record
   erb_lint
   factory_bot_rails
+  faker
   faraday
   ffi-libarchive
   gd2-ffij (>= 0.4.0)
@@ -547,6 +551,7 @@ DEPENDENCIES
   simplecov
   simplecov-lcov
   strong_migrations
+  timecop
   uglifier (>= 1.3.0)
   validates_email_format_of (>= 1.5.1)
   vendorer

config/initializers/factory_bot_strategy_find_or_create.rb

@@ -0,0 +1,33 @@
+# From https://stackoverflow.com/a/65700370/
+if Rails.env.development?
+  module FactoryBot
+    module Strategy
+      # Does not work when passing objects as associations: `FactoryBot.find_or_create(:entity, association: object)`
+      # Instead do: `FactoryBot.find_or_create(:entity, association_id: id)`
+      class FindOrCreate
+        def initialize
+          @build_strategy = FactoryBot.strategy_by_name(:build).new
+        end
+
+        delegate :association, :to => :@build_strategy
+
+        def result(evaluation)
+          attributes = attributes_shared_with_build_result(evaluation)
+          evaluation.object.class.where(attributes).first || FactoryBot.strategy_by_name(:create).new.result(evaluation)
+        end
+
+        private
+
+        # Here we handle possible mismatches between initially provided attributes and actual model attrbiutes
+        # For example, devise's User model is given a `password` and generates an `encrypted_password`
+        # In this case, we shouldn't use `password` in the `where` clause
+        def attributes_shared_with_build_result(evaluation)
+          object_attributes = evaluation.object.attributes
+          evaluation.hash.filter { |k, _v| object_attributes.key?(k.to_s) }
+        end
+      end
+    end
+
+    register_strategy(:find_or_create, Strategy::FindOrCreate)
+  end
+end

lib/tasks/development.rake

@@ -0,0 +1,28 @@
+# Create some fake data to help developers get started with the app
+
+# This rake task will add some fake data, which is particularly helpful when
+# developing the user interface, since it avoids time-consuming manual work
+
+# The data should be created in a idempotent fashion, so that the script can be
+# run again without causing errors or duplication.
+
+if Rails.env.development?
+  desc "Populate the development database with some fake data"
+  namespace "dev" do
+    task "populate" => :environment do
+      include FactoryBot::Syntax::Methods
+
+      # Ensure we generate the same data each time this is run
+      Faker::Config.random = Random.new(42)
+
+      # Ensure that all dates (e.g. terms_agreed) are consistent
+      Timecop.freeze(Time.utc(2015, 10, 21, 12, 0, 0)) do
+        user = find_or_create(:user, :display_name => Faker::Name.name)
+
+        find_or_create(:diary_entry, :title => Faker::Lorem.sentence,
+                                     :body => Array.new(3) { Faker::Lorem.paragraph(:sentence_count => 12) }.join("\n\n"),
+                                     :user_id => user.id)
+      end
+    end
+  end
+end