Now that we have our high level design, let's start desiging how we are actually going to build our flash card application. The first thing we might want to design is: how does the user specify questions?

We already answered this to some degree in SPC-format. Let's expand it a bit.

# SPC-format
partof:
- REQ-purpose
###
The user shall be able to easily configure the quiz
questions through a simple csv format consisting of two
columns: the question and the answer.

The format of the csv file **shall** be a csv file of the form:

    City, Capitol

> Note: whitespace will be ignored

## [[.question]]
The `Question` class shall be the primary datatype used for questions in the
application. Quetions shall:
- Store the question and answer.
- Provide a method `ask` to ask the user the question
  and validate the answer.

## [[.validate]]
Input questions **shall** be validated to:
- Guarantee against duplicates.
- Guarantee that the data format is correct.

There are a few things here, so let's take a look:

• We expanded how the user can configure the questions (the CSV format itself)
• We created two subartifacts, .question and .validate.
  • Having the [[.subart]] anywhere within the text is enough to create these.
  • We can now link these subarts in code and they are necessary for our artifact to be considered "complete".

Let's also define a couple of unit tests. You could do this using a new TST-format (or any other name) artifact.

However, artifact has what are called tst-subarts specifically for the purpose of defining unit test coverage that you want. Simply add the following section to SPC-format:

## Unit Tests:
- Invalid: make sure invalid inputs don't work
  - [[.tst-invalid_cols]]: Test invalid number of columns (0, 1, and 3).
  - [[.tst-duplicates]]: Test duplicate names.
- Make sure loading works.
  - [[.tst-basic]]: Loading a raw string and validating it.
  - [[.tst-load]]: Loading a valid csv file path and validating it.

These will allow us to implement testing for SPC-format without having to create new artifacts.