Step by Step Guide to Building an Expensify API Integration in Go

Introduction

Hey there, fellow Go enthusiast! Ready to dive into the world of expense management? We're about to embark on a journey to integrate the Expensify API into your Go project. Don't worry, it's not as daunting as it sounds. With the help of the expensify package, we'll have you up and running in no time.

Prerequisites

Before we jump in, make sure you've got:

• Go installed on your machine (I know, obvious, right?)
• An Expensify account with API credentials (if you don't have one, go grab it real quick)

Setting Up the Project

Let's kick things off by creating a new Go module:

mkdir expensify-integration && cd expensify-integration
go mod init expensify-integration

Now, let's get that expensify package:

go get github.com/expensify/expensify-api-go

Initializing the Expensify Client

Time to get our hands dirty with some code:

package main

import (
    "github.com/expensify/expensify-api-go"
)

func main() {
    client := expensify.NewClient("your-partner-user-id", "your-partner-user-secret")
    // We're ready to rock!
}

Basic API Operations

Creating an Expense

Let's add that coffee you definitely needed this morning:

expense := &expensify.Expense{
    Amount: 3.50,
    Merchant: "Coffee Shop",
    Category: "Food",
}
createdExpense, err := client.CreateExpense(expense)
if err != nil {
    // Handle error
}

Retrieving Expenses

Time to face the music and see how much you've spent:

expenses, err := client.GetExpenses()
if err != nil {
    // Handle error
}
for _, exp := range expenses {
    fmt.Printf("Spent $%.2f at %s\n", exp.Amount, exp.Merchant)
}

Updating an Expense

Oops, that coffee was actually $4.50:

updatedExpense := &expensify.Expense{
    ID: createdExpense.ID,
    Amount: 4.50,
}
_, err = client.UpdateExpense(updatedExpense)
if err != nil {
    // Handle error
}

Deleting an Expense

Changed your mind about expensing that coffee? No judgment here:

err = client.DeleteExpense(createdExpense.ID)
if err != nil {
    // Handle error
}

Advanced Features

Handling Pagination

For when you've got more expenses than you can count:

page := 1
for {
    expenses, hasMore, err := client.GetExpensesWithPagination(page, 50)
    if err != nil {
        // Handle error
    }
    // Process expenses
    if !hasMore {
        break
    }
    page++
}

Working with Reports

Group those expenses into a neat little report:

report := &expensify.Report{
    Title: "Q2 Business Expenses",
}
createdReport, err := client.CreateReport(report)
if err != nil {
    // Handle error
}

Managing Categories and Tags

Keep things organized:

categories, err := client.GetCategories()
if err != nil {
    // Handle error
}

err = client.AddTagToExpense(expenseID, "client-meeting")
if err != nil {
    // Handle error
}

Error Handling and Best Practices

Always be prepared for the unexpected:

if err != nil {
    if apiErr, ok := err.(*expensify.APIError); ok {
        if apiErr.Code == expensify.ErrRateLimit {
            // Implement exponential backoff
        }
    }
    // Handle other errors
}

Testing the Integration

Don't forget to test! Here's a quick example:

func TestCreateExpense(t *testing.T) {
    mockClient := &MockExpensifyClient{}
    expense := &expensify.Expense{Amount: 10.00, Merchant: "Test"}
    createdExpense, err := mockClient.CreateExpense(expense)
    assert.NoError(t, err)
    assert.Equal(t, expense.Amount, createdExpense.Amount)
}

Deployment Considerations

Keep those secrets safe:

client := expensify.NewClient(
    os.Getenv("EXPENSIFY_PARTNER_USER_ID"),
    os.Getenv("EXPENSIFY_PARTNER_USER_SECRET"),
)

Conclusion

And there you have it! You've just built a solid Expensify API integration in Go. Remember, this is just the tip of the iceberg. The Expensify API has a lot more to offer, so don't be afraid to explore further.

Keep coding, keep expensing, and most importantly, keep that coffee flowing! 🚀☕️