Code Explainers

Go code explainers

go 
package email
 
import (
	"errors"

Normalizing and deduping email addresses in Go

validation normalization deduplication
Intermediate 8 steps
go 
type PostCursor struct {
	CreatedAt time.Time
	ID        int64
}

Keyset pagination with cursors in Go

pagination keyset-cursor database
Intermediate 8 steps
go 
package config
 
import (
	"fmt"

Parsing timeout config in Go

configuration validation error-wrapping
Intermediate 7 steps
go 
func (h *WebhookHandler) HandleBatch(c *gin.Context) {
	var payload BatchWebhookPayload
	if err := c.ShouldBindJSON(&payload); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid payload"})

Handling batched webhooks in Gin

webhooks signature-verification job-queue
Intermediate 7 steps
go 
package config
 
import "time"
 

The functional options pattern in Go

functional-options closures immutability
Intermediate 7 steps
go 
package admin
 
import (
	"net/http"

Building a protected admin area in Gin

routing middleware authentication
Intermediate 6 steps
go 
package middleware
 
import (
	"errors"

Capping request body size in Gin

middleware request limits error handling
Intermediate 5 steps
go 
package batch
 
import "fmt"
 

Splitting a slice into batches in Go

generics slices error-handling
Intermediate 6 steps
go 
package security
 
import (
	"crypto/hmac"

Signing and verifying payloads with HMAC in Go

hmac cryptography authentication
Intermediate 5 steps
go 
package handlers
 
import (
	"context"

Liveness vs readiness health checks in Gin

health-checks dependency-injection context-timeout
Intermediate 7 steps
go 
package handlers
 
import (
	"net/http"

Custom query validation in Gin

validation query-binding deduplication
Intermediate 8 steps
go 
package storage
 
import (
	"context"

A SQLite-backed order store in Go

database/sql sqlite error-wrapping
Intermediate 7 steps
go 
package auth
 
import (
	"errors"

Hashing and verifying passwords with bcrypt in Go

password-hashing bcrypt error-handling
Intermediate 7 steps
go 
package fsutil
 
import (
	"io/fs"

Walking a directory tree to find large files in Go

filesystem recursion closures
Intermediate 7 steps
go 
package middleware
 
import (
	"log"

Per-IP rate limiting middleware in Gin

rate-limiting middleware concurrency
Intermediate 8 steps
go 
func handleUpload(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseMultipartForm(32 << 20); err != nil {
		http.Error(w, "failed to parse form: "+err.Error(), http.StatusBadRequest)
		return

Handling multi-file uploads in Go

multipart file-upload http-handler
Intermediate 9 steps
go 
package render
 
import (
	"net/http"

How Gin renders MsgPack responses

serialization content-type interface-implementation
Intermediate 5 steps
go 
package proxy
 
import (
	"log"

Building a hardened Go reverse proxy

reverse-proxy http timeouts
Intermediate 7 steps