Linters are essential tools that help identify obvious errors and perform static code analysis to improve overall code quality. No matter how experienced you are, there’s always a chance to miss something. Linting helps catch these issues early during the development phase.

Go provides several built-in tools like gofmt for formatting and govet for reporting suspicious constructs. Additionally, the community maintains a vast number of specialized linters:

• fieldalignment: Detects structs that could use less memory if fields were sorted differently.
• unused: Checks for unused constants, variables, functions, and types.
• gofumpt: Enforces a stricter format than gofmt.
• goconst: Finds repeated strings that could be replaced by constants.
• gocyclo: Computes the cyclomatic complexity of functions.
• errcheck: Detects unchecked errors in Go programs.

Managing and running these tools individually can be slow and cumbersome.

🤓 Entering Golangci-lint

golangci-lint is a Go linters aggregator. It runs linters in parallel, reuses the Go build cache, and caches analysis results for much faster performance on subsequent runs.

It is fast, utilizes YAML-based configuration, has minimal false positives, and provides beautiful, colorized output. Most importantly, it includes many linters out of the box, so you don’t need to install them separately.

Installation

# Install to $(go env GOPATH)/bin/golangci-lint
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.45.2

# Verify installation
golangci-lint --version

Running the Linter

Let’s introduce a redundant import to see if golangci-lint catches it:

package main

import "fmt"
import "os" // Unused import
import "unsafe"

type TerraformResource struct {
    Cloud               string
    Name                string
    HaveDSL             bool
    PluginVersion       string
    IsVersionControlled bool
    TerraformVersion    string
    ModuleVersionMajor  int32
}

func main() {
    var d TerraformResource
    d.Cloud = "aws"
    fmt.Printf("Total Memory Usage StructType:d %T => [%d]\n", d, unsafe.Sizeof(d))
}

Now, run the linter:

>> golangci-lint run ./demo.go

demo.go:4:8: "os" imported but not used (typecheck)
import "os"
       ^

It automatically detected the unused import. golangci-lint supports over 100 linters. You can see the full list using:

>> golangci-lint help linters

Memory Alignment with fieldalignment

One particularly useful tool is fieldalignment. It identifies if your structs are optimized for memory usage. I wrote a detailed blog about memory alignment here.

>> fieldalignment demo.go
demo:6:24: struct of size 88 could be 72

Using these tools regularly ensures your code is not only correct but also efficient and maintainable.

Happy Coding!!