Generate Test Data for Rails Projects

This script allows you to generate test data to populate an ActiveRecord supported project such as a Rails application for example. The data is designed to look real so that it can be used for test or demo purposes.

Requirements

• Ruby 2.3.3 or higher
• ActiveRecord gem

Installation

1. Download the repository

Usage

1. Identify the location of your Rails application to the script

$ ruby bin/gendata.rb --rails-app-path /projects/demo

2. Generate a list of tables from the database. This assumes that you have already run all pending database creation and migration scripts first. You will also need to specify which RAILS_ENV database you are targetting. This will typically be one of the following: development, test, production.

$ ruby bin/gendata.rb --list-tables --rails-env development

This will create the file tables.yml in the config folder of this script. It will look similar to the one from the demo project where each table will have three lines associated with it.

---
schema_migrations:
  :records_to_load: 0
  :truncate_before_load: false
people:
  :records_to_load: 0
  :truncate_before_load: false

3. Edit the tables.yml file to identify which tables you want to generate data for. You can do this by setting records_to_load to a value greater than 0. If you also want to delete all data in the table as well before loading it then also set truncate_before_load value to true.

4. The next step is generate a list of columns for each of the tables. You must specify the same RAILS_ENV parameter that you used in step 2.

$ ruby bin/gendata.rb --list-columns --rails-env development

This will create one file for each table of the form, tablename.yml. It will look similar to the one from the demo project where each column will have eight lines associated with it. The sample below only shows information from the first two columns.

---
  id:
    :precision: 
    :scale: 
    :limit: 
    :sql_type: INTEGER
    :null: false
    :default: 
    :generator: ignore_generator
  first_name:
    :precision: 
    :scale: 
    :limit: 
    :sql_type: varchar
    :null: true
    :default: 
    :generator: ignore_generator

4. Edit the tablename.yml file to identify each column (if any) that you want to load data for and what kind of data. You indicate this by replacing the default generator of ignore_generator with one that actually causes data to be loaded.

For the purposes of the demo we will only consider the generator lines for the people table. Here we have assigned the first name, last name, and date generators to the applicable fields.

  first_name:
    :generator: name_generator.first_name
  last_name:
    ...
    :generator: name_generator.last_name
  email:
    ...
    :generator: ignore_generator
  birth_date:
    ...
    :generator: date_generator.date

5. Now we are ready to generate data and populate the tables. We will need to specify the RAILS_ENV again. We can optionally specify a seed value which will cause repeatable results to be generated from multiple runs of the script.

$ ruby bin/gendata.rb --generate-data --rails-env development --seed 5
Generators seeded with value 5
Starting to process people...
  Loading record 1 of 5
  Loading record 2 of 5
  Loading record 3 of 5
  Loading record 4 of 5
  Loading record 5 of 5
Finished loading people

Remarks

If your database uses SSL for connections then you can specify the following additional parameters for the --list-tables, --list-columns, and --generate-data options.

• --ssl-ca-cert include the path and file name of the certificate authority
• --ssl-client-cert include the path and file name of the client certificate
• --ssl-client-key include the path and file name of the client certificate public key

Available Generators

There is an additional file test_generators.rb in the bin folder. The sole purpose of this file is to be a sandbox for playing with the different generators to see their output. This script is not actually used by the tool so it can be freely modified without fear of breaking something. It also does not interface with the databases in any way. Just edit the file in any editor and then execute from the command line using the Ruby interpreter.

address_generator

This generator can populate street, city, state, zipcode, phone and email fields.

  :generator: address_generator.street  # 14 Bird Lane

  :generator: address_generator.city # Hartford

  :generator: address_generator.state_name # Connecticut

  :generator: address_generator.state_abbrev # CT

  :generator: address_generator.zipcode  # 16014

  :generator: address_generator.phone  # 123-456-7890

  :generator: address_generator.email  # [email protected]

date_generator

This generator can generate date or datetime values between January 1, 1900 and the current date.

The default date range is at '1900-01-01' and the current date within the gendata.rb script. It can be modified by changing the values passed to date_generator.generate(min_value,max_value) line. The dates for the min and max value parameters should be specified as 'YYYY-MM-DD' format.

  :generator: date_generator.date  # 1997-09-12

  :generator: date_generator.datetime # 1915-02-12T14:47:38+00:00

ignore_generator

This generator will cause the associated column to not be populated with data.

  :generator: ignore_generator

name_generator

This generator can populate first, middle, last, suffix, and gender fields.

  :generator: name_generator.first_name  # William

  :generator: name_generator.middle_name  # James

  :generator: name_generator.middle_initial # J

  :generator: name_generator.last_name # Porter

  :generator: name_generator.suffix  # Jr

  :generator: name_generator.gender  # M

  :generator: name_generator.gender_name # Male

number_generator

This generator can generate either integer or decimal numeric data.

  :generator: number_generator.integer   # 10

  :generator: number_generator.decimal   # 10.5

string_generator

This generator can generate strings of random alphanumeric data or uuid's.

The default length of all strings, excluding the uuid, is fixed at 5 characters within the gendata.rb script. It can be modified by changing the value passed in the string_generator.generate(5) line.

  :generator: string_generator.uuid # b74ae5e4-7070-4835-99a1-55b37bb7575c

  :generator: string_generator.alpha  # YuJnM

  :generator: string_generator.numeric # 69701

  :generator: string_generator.alpha_numeric  # 2iBh1

Copyright (c) 2016 Thomas Chester. This software is licensed under the MIT License.