Powerful Command-Line Applications in Go/

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Initializing the Pomodoro Application

Initializing the Pomodoro Application

Learn how to start the application by developing the Pomodoro package.

We'll cover the following...

Let’s start this application by developing the Pomodoro package that contains the business logic to create and use the pomodoro timer. By creating a separate package for the business logic, we can test it independently of the user interface and use the same package in other projects.

Creating the interval.go file

We create the file interval.go, which is where we’ll put the timer functionality. The Pomodoro technique records time in intervals that can be of different types such as Pomodoro, short breaks, or long breaks. We open this file in our text editor and add the package definition and import section.

We’ll use the following packages:

  • context to carry context and cancellation signals from the user interface.
  • errors to define custom errors.
  • fmt to format output.
  • time to handle time-related data.
package pomodoro
import (
"context"
"errors"
"fmt"
"time"
)
Importing the required list

Next, we define two sets of constants to represent the different categories and states for a Pomodoro interval. We start with the category. As mentioned before, a Pomodoro interval can be one of three categories: Pomodoro, short break, or long break. We create a set of constants called CategoryPomodoro, CategoryShortBreak, and CategoryLongBreak to represent them:

// Category constants
const (
    CategoryPomodoro = "Pomodoro"
    CategoryShortBreak = "ShortBreak"
    CategoryLongBreak = "LongBreak"
)

Then, we add the constant set for the state. We represent the state as an integer number to save space when saving this data in a database. ...