Code Explainers

Go code explainers

go 
package token
 
import (
	"crypto/rand"

Generating secure random tokens in Go

cryptography randomness encoding
Intermediate 5 steps
go 
package middleware
 
import (
	"bytes"

Capturing response bodies in Gin middleware

middleware response-capture struct-embedding
Intermediate 7 steps
go 
func GetArticle(c *gin.Context) {
	id := c.Param("id")
 
	article, err := articleRepo.FindByID(c.Request.Context(), id)

Conditional GET with ETags in Gin

http-caching etag conditional-requests
Intermediate 7 steps
go 
package middleware
 
import (
	"net/http"

How a www-to-apex redirect middleware works in Gin

middleware http-redirect closures
Intermediate 5 steps
go 
package handlers
 
import (
	"errors"

Turning Gin binding errors into field messages

input validation struct tags error handling
Intermediate 9 steps
go 
type Employee struct {
	Department string
	LastName   string
	FirstName  string

Multi-key sorting in Go

sorting comparators tie-breaking
Intermediate 6 steps
go 
func (r *EventRepository) BatchInsert(ctx context.Context, events []Event) error {
	if len(events) == 0 {
		return nil
	}

Batch inserting rows in a Go transaction

transactions batching database
Intermediate 7 steps
go 
package main
 
import (
	"html/template"

Auto-escaping HTML with Go templates

templating xss auto-escaping
Intermediate 6 steps
go 
package middleware
 
import (
	"strconv"

Instrumenting a Gin API with Prometheus

middleware observability metrics
Intermediate 6 steps
go 
type SensorReading struct {
	DeviceID    string    `json:"device_id" binding:"required"`
	Temperature float64   `json:"temperature"`
	RecordedAt  time.Time `json:"recorded_at" binding:"required"`

Streaming NDJSON ingestion in Gin

streaming batching json-decoding
Advanced 10 steps
go 
package handlers
 
import (
	"net/http"

Struct-level validation for partial updates in Gin

validation struct-tags partial-update
Intermediate 7 steps
go 
package fetcher
 
import (
	"context"

Bounded-concurrency HTTP fetching in Go

concurrency semaphore context-cancellation
Advanced 9 steps
go 
package inventory
 
import (
	"encoding/csv"

Parsing CSV into typed structs in Go

csv-parsing error-wrapping type-conversion
Intermediate 8 steps
go 
package search
 
import (
	"net/url"

Building a query URL from a Filter struct in Go

url-encoding struct-methods input-validation
Intermediate 8 steps
go 
package handlers
 
import (
	"net/http"

Content negotiation in Gin handlers

content-negotiation struct-tags rest-api
Intermediate 4 steps
go 
package ratelimit
 
import (
	"context"

A token bucket rate limiter in Go

rate-limiting concurrency goroutines
Intermediate 7 steps
go 
package handlers
 
type BookURI struct {
	Collection string `uri:"collection" binding:"required,alphanum"`

Validating URI params in a Gin handler

input validation struct binding error handling
Intermediate 7 steps
go 
package cache
 
import (
	"context"

Cache-aside reads with singleflight in Go

caching singleflight concurrency
Advanced 8 steps