TestMain to print logs if failed

testmain_test.go

package componenttests

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestMain(m *testing.M) {
	deleteAllLogs(".")
	result := m.Run()
	if result != 0 {
		if _, exists := os.LookupEnv("CI"); exists {
			fmt.Print("\n\nSome test failed. Find and print logs.\n\n\n")
			printLogsForCI(".")
		} else {
			dir, err := filepath.Abs("logs")
			if err != nil {
				dir = "logs"
			}
			fmt.Printf("\n\nSome test failed. You can find logs here: %s\n\n\n", dir)
		}
	}
	os.Exit(result)
}

func deleteAllLogs(root string) {
	_ = filepath.Walk(root, func(relativePath string, info os.FileInfo, e error) error {
		path, err := filepath.Abs(relativePath)
		if err != nil {
			path = relativePath
		}
		if e != nil {
			fmt.Printf("Failed to access path %q: %v\n", path, e)
			return e
		}
		if info.IsDir() {
			return nil
		}
		if filepath.Ext(path) != ".log" {
			return nil
		}
		err = os.Remove(path)
		if err != nil {
			fmt.Printf("Can't delete log %s: %v\n", path, err)
			return nil
		}
		fmt.Printf("Log deleted %s\n", path)
		return nil
	})
}

func printLogsForCI(root string) {
	_ = filepath.Walk(root, func(relativePath string, info os.FileInfo, e error) error {
		path, err := filepath.Abs(relativePath)
		if err != nil {
			path = relativePath
		}
		if e != nil {
			fmt.Printf("Failed to access path %q: %v\n", path, e)
			return e
		}
		if info.IsDir() {
			return nil
		}
		if filepath.Ext(path) != ".log" {
			return nil
		}
		name := strings.ReplaceAll(info.Name(), " ", "_")
		fmt.Printf("::group::%s\n", name)
		fmt.Printf("=== Found log: %s\n\n", path)
		printFile(path)
		fmt.Printf("::endgroup::%s\n", name)
		return nil
	})
}

func printFile(path string) {
	file, err := os.Open(path)
	if err != nil {
		fmt.Printf("Failed to open file %q: %v\n", path, err)
		return
	}
	_, err = io.Copy(os.Stdout, file)
	if err != nil {
		fmt.Printf("Failed to print file content %q: %v\n", path, err)
		return
	}
	fmt.Print("\n")
}