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1. Getting Started

Golang

Installation

Install it with homebrew, add it to the PATH and check the version to make sure it installed correctly. The command below will work for Macs with an M1, M2, M3, etc. chip.

arch -x86_64 brew install go

export GOPATH=$HOME/go
export GOROOT="$(brew --prefix golang)/libexec"
export PATH="$PATH:${GOPATH}/bin:${GOROOT}/bin"

go version

The go command

go mod init

Run the go mod init command, giving it your module path -- here, use example.com/greetings. If you publish a module, this must be a path from which your module can be downloaded by Go tools. That would be your code's repository.

$ go mod init example.com/greetings
go: creating new go.mod: module example.com/greetings

go run

We can run a simple code block like:

package main

import "fmt"

func main() {
	fmt.Println("Hello, World!")
}

with the command go run hello.go where hello.go is the name of the file. This will print “Hello, world!” into the terminal. There is no binary file saved in the folder because go run will build the binary, execute it and deletes it. This is useful for quickly testing smaller programs.

go build

To actually build the binary, we run go build hello.go which creates an exectuable called hello (or hello.exe on windows). It will match the name of the file or package that was passed in.

go fmt

Format your code to remove all whitespace, extra indentations, etc.

go vet

We can fix errors such as passing the wrong number of parameters to formatting methods or assigning values to unused variables. go vet will find these kinds of errors.

func main() {
	fmt.Println("Hello, World!")
	var hello int = 1;

}

nick@Nicks-MacBook-Pro-2 ch1 % go vet
# ch1/ch1
vet: ./hello.go:7:6: hello declared and not used

Third-Party Go Tools

Instead of using something like Maven (Java) or NPM (JavaScript), we can share the projects via source code repositories. E.g.

go install github.com/rakyll/hey@latest

The @ is the version we want to install. Once this installs hey, we can use it as it’s installed into our $GOPATH/bin directory - we can run it with:

hey https://www.nickderaj.com

golint

We want to enforce idiomatic Go code across our files, so we use tools like linters to make this happen automatically. One of the tools we can use is called golint which we install with go install [golang.org/x/lint/golint@latest](http://golang.org/x/lint/golint@latest) and simply run the golint tool. It suggests:

golangci-lint

Combines multiple tools like golint, go vet and multiple other code quality tools into one. It can be installed with the following

# binary will be $(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 v1.55.2

golangci-lint --version

then simply run golangci-lint run to check the code for any errors

Makefile

We can create a Makefile that contains the following:

.DEFAULT_GOAL := build

fmt:
	go fmt ./...
.PHONY:fmt

vet:
	go vet ./...
.PHONY:vet

lint:
	golint ./..
.PHONY:lint

build:
	go build hello.go
.PHONY: build

This will run all of the commands to make sure the code is formatted, vetted for non-obvious errors and compiled.

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