You just started a new job. Your boss comes over and says that their CRM (customer-relationship-management) app is too hard to work with, and that you need to do some data transformation. They tell you that you will get a big hash of all the data, and you need to write some code that will take that data and convert it to other data structures more useful to the business.
The original data set has data about people and companies, and about which person works for which companies as well as what their job titles are. The original data looks like this:
CRM = {
:people => [
{
:id => 20,
:first_name => "Savannah",
:last_name => "Clementina",
:employments => []
},
{
:id => 32,
:first_name => "Elyse",
:last_name => "Jensen",
:employments =>
[
{
:company_id => 4,
:title => "Chief Communications Consultant"
}
]
}
],
:companies => [
{
:id => 0,
:name => "Nicolas and Sons"
},
{
:id => 1,
:name => "Mueller LLC"
},
{
:id => 2,
:name => "Mohr, King and Gleason"
}
]
}
Write some code that will return an array of companies, and the people who work for them. For example:
[
{
name: "Nicolas and Sons",
employees: [
{
:id => 20,
:first_name => "Savannah",
:last_name => "Clementina",
:title => "Chief Communications Consultant"
},
{
:id => 46,
:first_name => "Elyse",
:last_name => "Jensen",
:title => "Human Directives Engineer"
},
]
}
]
Write some code that will return an array of all the employments, including the person name, company name, person id, company id and title.
[
{
:company_id => 4,
:company_name => "Nicolas and Sons",
:person_id => 20,
:person_first_name => "Savannah",
:person_last_name => "Clementina",
:title => "Chief Communications Consultant"
},
{
:company_id => 6,
:company_name => "Mueller LLC",
:person_id => 20,
:person_first_name => "Elyse",
:person_last_name => "Jensen",
:title => "Human Directives Engineer"
},
]
Write some code that will return an array of all the people
who have no employments. The resulting hashes in the array should
not include the :employments
key.
[
{
:id => 20,
:first_name => "Savannah",
:last_name => "Clementina"
},
{
:id => 32,
:first_name => "Elyse",
:last_name => "Jensen",
}
]
Test data has been provided in the data.rb
file.
Write all of this test-first. In your specs, don't use the
test data from data.rb
- instead, write your own data
structures that are similar to the CRM
data.
Then, in IRB, run your code against the test data to see it in action.
Write a command line tool that will print this data in a pretty way to the terminal.
- Fork
- Clone
- Turn on TravisCI for the fork by visiting https://travis-ci.org/profile/, clicking the "Sync now" button and scrolling down to find the repository to build.
- Create a new branch for your work using
git checkout -b v1
- Implement specs and code
- Push using
git push -u origin v1
This warmup can be completed multiple times to increase your comfort level with the material. To work on this from scratch, you can:
- Add an upstream remote that points to the original repo
git remote add upstream [email protected]:gSchool/data-challenge.git
- Fetch the latest from the upstream remote using
git fetch upstream
- Create a new branch from the master branch of the upstream remote
git checkout -b v2 upstream/master
- Implement specs and code
- Push using
git push -u origin v2
Each time you do the exercise, create a new branch. For example the 3rd time you do the exercise the branch name will be v3 instead of v2.