urfave-cli/internal/build/build.go

// local build script file, similar to a makefile or collection of bash scripts in other projects

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io/ioutil"
	"log"
	"math"
	"os"
	"os/exec"
	"strings"

	"github.com/urfave/cli/v2"
)

var packages = []string{"cli", "altsrc"}

func main() {
	app := cli.NewApp()

	app.Name = "builder"
	app.Usage = "Generates a new urfave/cli build!"

	app.Commands = cli.Commands{
		{
			Name:   "vet",
			Action: VetActionFunc,
		},
		{
			Name:   "test",
			Action: TestActionFunc,
		},
		{
			Name:   "gfmrun",
			Action: GfmrunActionFunc,
		},
		{
			Name:   "toc",
			Action: TocActionFunc,
		},
		{
			Name:   "check-binary-size",
			Action: checkBinarySizeActionFunc,
		},
	}

	err := app.Run(os.Args)
	if err != nil {
		log.Fatal(err)
	}
}

func runCmd(arg string, args ...string) error {
	cmd := exec.Command(arg, args...)

	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	return cmd.Run()
}

func VetActionFunc(_ *cli.Context) error {
	return runCmd("go", "vet")
}

func TestActionFunc(c *cli.Context) error {
	for _, pkg := range packages {
		var packageName string

		if pkg == "cli" {
			packageName = "github.com/urfave/cli/v2"
		} else {
			packageName = fmt.Sprintf("github.com/urfave/cli/v2/%s", pkg)
		}

		coverProfile := fmt.Sprintf("--coverprofile=%s.coverprofile", pkg)

		err := runCmd("go", "test", "-v", coverProfile, packageName)
		if err != nil {
			return err
		}
	}

	return testCleanup()
}

func testCleanup() error {
	var out bytes.Buffer

	for _, pkg := range packages {
		file, err := os.Open(fmt.Sprintf("%s.coverprofile", pkg))
		if err != nil {
			return err
		}

		b, err := ioutil.ReadAll(file)
		if err != nil {
			return err
		}

		out.Write(b)
		err = file.Close()
		if err != nil {
			return err
		}

		err = os.Remove(fmt.Sprintf("%s.coverprofile", pkg))
		if err != nil {
			return err
		}
	}

	outFile, err := os.Create("coverage.txt")
	if err != nil {
		return err
	}

	_, err = out.WriteTo(outFile)
	if err != nil {
		return err
	}

	err = outFile.Close()
	if err != nil {
		return err
	}

	return nil
}

func GfmrunActionFunc(c *cli.Context) error {
	filename := c.Args().Get(0)
	if filename == "" {
		filename = "README.md"
	}

	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	var counter int
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		if strings.Contains(scanner.Text(), "package main") {
			counter++
		}
	}

	err = file.Close()
	if err != nil {
		return err
	}

	err = scanner.Err()
	if err != nil {
		return err
	}

	return runCmd("gfmrun", "-c", fmt.Sprint(counter), "-s", filename)
}

func TocActionFunc(c *cli.Context) error {
	filename := c.Args().Get(0)
	if filename == "" {
		filename = "README.md"
	}

	err := runCmd("markdown-toc", "-i", filename)
	if err != nil {
		return err
	}

	err = runCmd("git", "diff", "--exit-code")
	if err != nil {
		return err
	}

	return nil
}

// checkBinarySizeActionFunc checks the size of an example binary to ensure that we are keeping size down
// this was originally inspired by https://github.com/urfave/cli/issues/1055, and followed up on as a part
// of https://github.com/urfave/cli/issues/1057
func checkBinarySizeActionFunc(c *cli.Context) (err error) {
	const (
		sourceFilePath       = "./internal/example/example.go"
		builtFilePath        = "./internal/example/built-example"
		desiredMinBinarySize = 4.7
		desiredMaxBinarySize = 5.0
		badNewsEmoji         = "🚨"
		goodNewsEmoji        = "✨"
		checksPassedEmoji    = "✅"
		mbStringFormatter    = "%.1fMB"
	)

	// build example binary
	err = runCmd("go", "build", "-o", builtFilePath, sourceFilePath)
	if err != nil {
		return err
	}

	// get file into
	fileInfo, err := os.Stat(builtFilePath)
	if err != nil {
		return err
	}

	// get human readable size, in MB with one decimal place.
	// example output is: 35.2MB. (note: this simply an example)
	// that output is much easier to reason about than the `35223432`
	// that you would see output without the rounding
	fileSize := fileInfo.Size()
	roundedFileSize := math.Round(float64(fileSize)/float64(1000000)*10) / 10
	roundedFileSizeString := fmt.Sprintf(mbStringFormatter, roundedFileSize)

	// check against bounds
	isLessThanDesiredMin := roundedFileSize < desiredMinBinarySize
	isMoreThanDesiredMax := roundedFileSize > desiredMaxBinarySize
	desiredMinSizeString := fmt.Sprintf(mbStringFormatter, desiredMinBinarySize)
	desiredMaxSizeString := fmt.Sprintf(mbStringFormatter, desiredMaxBinarySize)

	// show guidance
	fmt.Println(fmt.Sprintf("\n%s is the current binary size", roundedFileSizeString))
	if isLessThanDesiredMin {
		fmt.Println(fmt.Sprintf("  %s current binary size is %s", goodNewsEmoji, desiredMinSizeString))
		os.Exit(1)
	} else {
		fmt.Println(fmt.Sprintf("  %s %s is the target minium size", checksPassedEmoji, desiredMinSizeString))
	}
	if isMoreThanDesiredMax {
		fmt.Println(fmt.Sprintf("  %s current binary size is %s", badNewsEmoji, desiredMaxSizeString))
		os.Exit(1)
	} else {
		fmt.Println(fmt.Sprintf("  %s %s is the target maximum size", checksPassedEmoji, desiredMaxSizeString))
	}

	return nil
}