gomockhandler.go

package main

import (
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"

	"golang.org/x/mod/modfile"

	"github.com/sanposhiho/gomockhandler/internal/mockgen"

	"github.com/sanposhiho/gomockhandler/internal/command"

	"github.com/sanposhiho/gomockhandler/internal/mockgen/reflectmode"
	"github.com/sanposhiho/gomockhandler/internal/mockgen/sourcemode"
	mockrepo "github.com/sanposhiho/gomockhandler/internal/repository/config"
)

var (
	configPath    = flag.String("config", "gomockhandler.json", "The path to config file.")
	forceGenerate = flag.Bool("f", false, "If true, it will also generate mocks whose source has not been updated.")
	pathFilter    = flag.String("target_dir", "", "By specifying a path, only mocks under that path will be targeted for commands `check` and `mockgen`")

	// flags for mockgen
	source          = flag.String("source", "", "[option for configure mockgen] (source mode) Input Go source file; enables source mode.")
	destination     = flag.String("destination", "", "[option for configure mockgen] Output file; defaults to stdout.")
	mockNames       = flag.String("mock_names", "", "[option for configure mockgen] Comma-separated interfaceName=mockName pairs of explicit config names to use. Mock names default to 'Mock'+ interfaceName suffix.")
	packageOut      = flag.String("package", "", "[option for configure mockgen] Package of the generated code; defaults to the package of the input with a 'mock_' prefix.")
	selfPackage     = flag.String("self_package", "", "[option for configure mockgen] The full package import path for the generated code. The purpose of this flag is to prevent import cycles in the generated code by trying to include its own package. This can happen if the config's package is set to one of its inputs (usually the main one) and the output is stdio so mockgen cannot detect the final output package. Setting this flag will then tell mockgen which import to exclude.")
	writePkgComment = flag.Bool("write_package_comment", true, "[option for configure mockgen] Writes package documentation comment (godoc) if true.")
	copyrightFile   = flag.String("copyright_file", "", "[option for configure mockgen] Copyright file used to add copyright header")
	imports         = flag.String("imports", "", "[option for configure mockgen] (source mode) Comma-separated name=path pairs of explicit imports to use.")
	auxFiles        = flag.String("aux_files", "", "[option for configure mockgen] (source mode) Comma-separated pkg=path pairs of auxiliary Go source files.")
	execOnly        = flag.String("exec_only", "", "[option for configure mockgen] (reflect mode) If set, execute this reflection program.")
	buildFlags      = flag.String("build_flags", "", "[option for configure mockgen] (reflect mode) Additional flags for go build.")
	progOnly        = flag.Bool("prog_only", false, "[option for configure mockgen] (reflect mode) Only generate the reflection program; write it to stdout and exit.")
	debugParser     = flag.Bool("debug_parser", false, "[option for configure mockgen] Print out parser results only.")
)

func main() {
	flag.Parse()

	repo := mockrepo.NewRepository()
	cmd := command.Runner{
		ConfigRepo: &repo,
		Args: command.Args{
			ConfigPath:      *configPath,
			ForceGenerate:   *forceGenerate,
			PathFilter:      *pathFilter,
			Source:          *source,
			Destination:     *destination,
			MockNames:       *packageOut,
			PackageOut:      *packageOut,
			SelfPackage:     *selfPackage,
			WritePkgComment: *writePkgComment,
			CopyrightFile:   *copyrightFile,
			Imports:         *imports,
			AuxFiles:        *auxFiles,
			ExecOnly:        *execOnly,
			BuildFlags:      *buildFlags,
			ProgOnly:        *progOnly,
			DebugParser:     *debugParser,
		},
	}

	var cmdFunc func()
	switch flag.Arg(0) {
	case "mockgen":
		cmdFunc = cmd.Mockgen
	case "check":
		cmdFunc = cmd.Check
	case "deletemock":
		cmdFunc = cmd.DeleteMock
	default:
		cmd.MockgenRunner = prepareMockgenRunner()
		cmdFunc = cmd.GenerateConfig
	}

	cmdFunc()
}

func prepareMockgenRunner() mockgen.Runner {
	if *destination == "" {
		log.Fatal("need -destination option")
	}

	if *source == "" {
		// reflect mode
		if flag.NArg() != 2 {
			log.Fatal("Expected exactly two arguments")
		}
		packageName := flag.Arg(0)
		interfaces := flag.Arg(1)
		if packageName == "." {
			dir, err := os.Getwd()
			if err != nil {
				log.Fatalf("Get current directory failed: %v", err)
			}
			packageName, err = packageNameOfDir(dir)
			if err != nil {
				log.Fatalf("Parse package name failed: %v", err)
			}
		}
		return reflectmode.NewRunner(packageName, interfaces, *source, *destination, *packageOut, *imports, *auxFiles, *buildFlags, *mockNames, *selfPackage, *copyrightFile, *execOnly, *progOnly, *writePkgComment, *debugParser)
	}

	// source mode
	return sourcemode.NewRunner(*source, *destination, *packageOut, *imports, *auxFiles, *mockNames, *selfPackage, *copyrightFile, *writePkgComment, *debugParser)
}

// Plundered from golang/mock/mockgen/parse.go.
// packageNameOfDir get package import path via dir
func packageNameOfDir(srcDir string) (string, error) {
	files, err := ioutil.ReadDir(srcDir)
	if err != nil {
		log.Fatal(err)
	}

	var goFilePath string
	for _, file := range files {
		if !file.IsDir() && strings.HasSuffix(file.Name(), ".go") {
			goFilePath = file.Name()
			break
		}
	}
	if goFilePath == "" {
		return "", fmt.Errorf("go source file not found %s", srcDir)
	}

	packageImport, err := parsePackageImport(srcDir)
	if err != nil {
		return "", err
	}
	return packageImport, nil
}

// Plundered from golang/mock/mockgen/parse.go.
//
// parseImportPackage get package import path via source file
// an alternative implementation is to use:
// cfg := &packages.Config{Mode: packages.NeedName, Tests: true, Dir: srcDir}
// pkgs, err := packages.Load(cfg, "file="+source)
// However, it will call "go list" and slow down the performance
func parsePackageImport(srcDir string) (string, error) {
	moduleMode := os.Getenv("GO111MODULE")
	// trying to find the module
	if moduleMode != "off" {
		currentDir := srcDir
		for {
			dat, err := ioutil.ReadFile(filepath.Join(currentDir, "go.mod"))
			if os.IsNotExist(err) {
				if currentDir == filepath.Dir(currentDir) {
					// at the root
					break
				}
				currentDir = filepath.Dir(currentDir)
				continue
			} else if err != nil {
				return "", err
			}
			modulePath := modfile.ModulePath(dat)
			return filepath.ToSlash(filepath.Join(modulePath, strings.TrimPrefix(srcDir, currentDir))), nil
		}
	}
	// fall back to GOPATH mode
	goPaths := os.Getenv("GOPATH")
	if goPaths == "" {
		return "", fmt.Errorf("GOPATH is not set")
	}
	goPathList := strings.Split(goPaths, string(os.PathListSeparator))
	for _, goPath := range goPathList {
		sourceRoot := filepath.Join(goPath, "src") + string(os.PathSeparator)
		if strings.HasPrefix(srcDir, sourceRoot) {
			return filepath.ToSlash(strings.TrimPrefix(srcDir, sourceRoot)), nil
		}
	}
	return "", errOutsideGoPath
}

var errOutsideGoPath = errors.New("source directory is outside GOPATH")