Code Explainers

Go code explainers

go 
package handlers
 
import (
	"encoding/json"

Parsing search query params in a Go handler

http-handlers input-validation defaults
Intermediate 7 steps
go 
package middleware
 
import (
	"bytes"

Idempotent requests in Gin with Redis

idempotency caching middleware
Advanced 10 steps
go 
package middleware
 
import (
	"context"

A deadline-enforcing HTTP middleware in Go

middleware context goroutines
Advanced 7 steps
go 
package logbuffer
 
import (
	"bufio"

A buffered logger with background flushing in Go

concurrency buffering context
Intermediate 8 steps
go 
package handler
 
import (
	"net/http"

Custom time validation in Gin

validation request-binding struct-tags
Intermediate 8 steps
go 
package middleware
 
import (
	"net/http"

Localized validation errors in Gin

middleware internationalization validation
Intermediate 8 steps
go 
func ListProducts(c *gin.Context) {
	allowed := map[string]string{
		"category": "category",
		"brand":    "brand",

Safe query filtering in a Gin handler

input-validation whitelisting query-building
Intermediate 7 steps
go 
func (h *ExportHandler) BulkExport(c *gin.Context) {
	projectID := c.Param("projectID")
 
	reports, err := h.reports.ListByProject(c.Request.Context(), projectID)

Streaming a ZIP download in Gin

streaming zip-archive http-headers
Intermediate 8 steps
go 
package middleware
 
import (
	"crypto/sha256"

Deduplicating concurrent requests in Gin

singleflight request-coalescing middleware
Advanced 8 steps
go 
package health
 
import (
	"context"

Building a health check endpoint in Go

health-check context-timeout dependency-probing
Intermediate 8 steps
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