How to use parsePackageImport method of main Package

...149		t.Run(testCase.name, func(t *testing.T) {150			for key, value := range testCase.envs {151				os.Setenv(key, value)152			}153			pkgPath, err := parsePackageImport(filepath.Clean(testCase.dir))154			if err != testCase.err {155				t.Errorf("expect %v, got %v", testCase.err, err)156			}157			if pkgPath != testCase.pkgPath {158				t.Errorf("expect %s, got %s", testCase.pkgPath, pkgPath)159			}160		})161	}162}163func TestParsePackageImport_FallbackGoPath(t *testing.T) {164	goPath, err := ioutil.TempDir("", "gopath")165	if err != nil {166		t.Error(err)167	}168	defer func() {169		if err = os.RemoveAll(goPath); err != nil {170			t.Error(err)171		}172	}()173	srcDir := filepath.Join(goPath, "src/example.com/foo")174	err = os.MkdirAll(srcDir, 0755)175	if err != nil {176		t.Error(err)177	}178	os.Setenv("GOPATH", goPath)179	os.Setenv("GO111MODULE", "on")180	pkgPath, err := parsePackageImport(srcDir)181	expected := "example.com/foo"182	if pkgPath != expected {183		t.Errorf("expect %s, got %s", expected, pkgPath)184	}185}186func TestParsePackageImport_FallbackMultiGoPath(t *testing.T) {187	var goPathList []string188	// first gopath189	goPath, err := ioutil.TempDir("", "gopath1")190	if err != nil {191		t.Error(err)192	}193	goPathList = append(goPathList, goPath)194	defer func() {195		if err = os.RemoveAll(goPath); err != nil {196			t.Error(err)197		}198	}()199	srcDir := filepath.Join(goPath, "src/example.com/foo")200	err = os.MkdirAll(srcDir, 0755)201	if err != nil {202		t.Error(err)203	}204	// second gopath205	goPath, err = ioutil.TempDir("", "gopath2")206	if err != nil {207		t.Error(err)208	}209	goPathList = append(goPathList, goPath)210	defer func() {211		if err = os.RemoveAll(goPath); err != nil {212			t.Error(err)213		}214	}()215	goPaths := strings.Join(goPathList, string(os.PathListSeparator))216	os.Setenv("GOPATH", goPaths)217	os.Setenv("GO111MODULE", "on")218	pkgPath, err := parsePackageImport(srcDir)219	expected := "example.com/foo"220	if pkgPath != expected {221		t.Errorf("expect %s, got %s", expected, pkgPath)222	}223}...

...62	dstPath, err := filepath.Abs(filepath.Dir(*output))63	if err != nil {64		log.Println("unable to determine destination file path:", err)65	}66	pkgPath, err := parsePackageImport(dstPath)67	if err != nil {68		log.Println("unable to infer output package name", err)69	}70	g.OutputPackagePath = pkgPath71	g.RootPackage = getRootPackage()72	return g73}74func getRootPackage() string {75	dir, err := os.Getwd()76	if err != nil {77		log.Fatalf("get current directory failed: %v", err)78	}79	packageName, err := packageNameOfDir(dir)80	if err != nil {81		log.Fatalf("parse package name failed: %v", err)82	}83	return packageName84}85func parsePackageImport(srcDir string) (string, error) {86	moduleMode := os.Getenv("GO111MODULE")87	// trying to find the module88	if moduleMode != "off" {89		currentDir := srcDir90		for {91			dat, err := ioutil.ReadFile(filepath.Join(currentDir, "go.mod"))92			if os.IsNotExist(err) {93				if currentDir == filepath.Dir(currentDir) {94					// at the root95					break96				}97				currentDir = filepath.Dir(currentDir)98				continue99			} else if err != nil {100				return "", err101			}102			modulePath := modfile.ModulePath(dat)103			return filepath.ToSlash(filepath.Join(modulePath, strings.TrimPrefix(srcDir, currentDir))), nil104		}105	}106	// fall back to GOPATH mode107	goPaths := os.Getenv("GOPATH")108	if goPaths == "" {109		return "", fmt.Errorf("GOPATH is not set")110	}111	goPathList := strings.Split(goPaths, string(os.PathListSeparator))112	for _, goPath := range goPathList {113		sourceRoot := filepath.Join(goPath, "src") + string(os.PathSeparator)114		if strings.HasPrefix(srcDir, sourceRoot) {115			return filepath.ToSlash(strings.TrimPrefix(srcDir, sourceRoot)), nil116		}117	}118	return "", errors.New("package not found")119}120// packageNameOfDir get package import path via dir121func packageNameOfDir(srcDir string) (string, error) {122	files, err := ioutil.ReadDir(srcDir)123	if err != nil {124		log.Fatal(err)125	}126	var goFilePath string127	for _, file := range files {128		if !file.IsDir() && strings.HasSuffix(file.Name(), ".go") {129			goFilePath = file.Name()130			break131		}132	}133	if goFilePath == "" {134		return "", fmt.Errorf("go source file not found %s", srcDir)135	}136	packageImport, err := parsePackageImport(srcDir)137	if err != nil {138		return "", err139	}140	return packageImport, nil141}...

...32	}33	if goFilePath == "" {34		return "", fmt.Errorf("go source file not found %s", srcDir)35	}36	packageImport, err := parsePackageImport(goFilePath, srcDir)37	if err != nil {38		return "", err39	}40	return packageImport, nil41}42func printModuleVersion() {43	if bi, exists := debug.ReadBuildInfo(); exists {44		fmt.Println(bi.Main.Version)45	} else {46		log.Printf("No version information found. Make sure to use " +47			"GO111MODULE=on when running 'go get' in order to use specific " +48			"version of the binary.")49	}50}51// parseImportPackage get package import path via source file52func parsePackageImport(source, srcDir string) (string, error) {53	cfg := &packages.Config{54		Mode:  packages.NeedName,55		Tests: true,56		Dir:   srcDir,57	}58	pkgs, err := packages.Load(cfg, "file="+source)59	if err != nil {60		return "", err61	}62	if packages.PrintErrors(pkgs) > 0 || len(pkgs) == 0 {63		return "", errors.New("loading package failed")64	}65	packageImport := pkgs[0].PkgPath66	// It is illegal to import a _test package....

1import (2func main() {3    if len(os.Args) < 2 {4        fmt.Println("Usage: importparser <file>")5        os.Exit(1)6    }7    fmt.Println("Parsing file", filename)8    err := parseFile(filename)9    if err != nil {10        fmt.Println("Error parsing file", filename, ":", err)11    }12}13func parseFile(filename string) error {14    f, err := parser.ParseFile(fset, filename, nil, parser.ImportsOnly)15    if err != nil {16    }17    for _, s := range f.Imports {18        if s.Name != nil {19        }20        path, err := strconv.Unquote(s.Path.Value)21        if err != nil {22        }23        fmt.Println("Import:", pkg, path)24    }25}26$ go run importparser.go 1.go

1import (2func main() {3    fset := token.NewFileSet()4import "fmt"5func main() { fmt.Println("Hello, playground") }6    f, err := parser.ParseFile(fset, "", src, parser.ImportsOnly)7    if err != nil {8        panic(err)9    }10    for _, s := range f.Imports {11        fmt.Println(s.Path.Value)12    }13}

1import (2	"go/importer"3func main() {4	f, err := parser.ParseFile(fset, "1.go", nil, parser.ParseComments)5	if err != nil {6	}7	pkg, err := parsePackageImport(fset, f, nil)8	if err != nil {9	}10	fmt.Println(pkg)11}12func parsePackageImport(fset *token.FileSet, f *ast.File, importer types.Importer) (*types.Package, error) {13	if importer == nil {14		conf.Importer = importer.Default()15	} else {16		conf.Importer = importer17	}18	return conf.Check(f.Name.Name, fset, []*ast.File{f}, nil)19}20./1.go:31: cannot use importer.Default() (type "code.google.com/p/go.tools/go/types".Importer) as type types.Importer in field value21I'm not sure what you mean by "main class". I think you want to import "code