refactor: simplify

go.mod

@@ -6,12 +6,10 @@ require (
 	github.com/ettle/strcase v0.1.1
 	github.com/hexops/gotextdiff v1.0.3
 	github.com/stretchr/testify v1.7.4
-	golang.org/x/mod v0.5.1
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -13,10 +13,6 @@ github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.4 h1:wZRexSlwd7ZXfKINDLsO4r7WBt3gTKONc6K/VesHvHM=
 github.com/stretchr/testify v1.7.4/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-golang.org/x/mod v0.5.1 h1:OJxoQ/rynoF0dcCdI7cLPktw/hR2cueqYfjm43oqK38=
-golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

mocktail.go

@@ -40,28 +40,19 @@ type InterfaceDesc struct {
 }
 
 func main() {
-	modulePath, err := getModulePath(os.Getenv("MOCKTAIL_TEST_PATH"))
+	info, err := getModuleInfo(os.Getenv("MOCKTAIL_TEST_PATH"))
 	if err != nil {
 		log.Fatal("get module path", err)
 	}
 
-	moduleName, err := getModuleName(modulePath)
-	if err != nil {
-		log.Fatal("get module name", err)
-	}
-
-	root := filepath.Dir(modulePath)
-
-	// moduleName: github.com/traefik/mocktail
-	// modulePath: /home/ldez/go/src/github.com/traefik/mocktail/go.mod
-	// root: /home/ldez/go/src/github.com/traefik/mocktail
+	root := info.Dir
 
 	err = os.Chdir(root)
 	if err != nil {
 		log.Fatalf("Chdir: %v", err)
 	}
 
-	model, err := walk(root, moduleName)
+	model, err := walk(root, info.Path)
 	if err != nil {
 		log.Fatalf("walk: %v", err)
 	}
@@ -120,21 +111,19 @@ func walk(root, moduleName string) (map[string]PackageDesc, error) {
 
 			interfaceName := line[i+len(commentTagPattern):]
 
-			filePkgName, err := filepath.Rel(root, filepath.Dir(fp))
-			if err != nil {
-				return err
-			}
-
-			var pkgName string
+			var importPath string
 			if index := strings.LastIndex(interfaceName, "."); index > 0 {
-				pkgName = interfaceName[:index]
+				importPath = path.Join(moduleName, interfaceName[:index])
+
 				interfaceName = interfaceName[index+1:]
 			} else {
-				pkgName = filePkgName
-			}
+				filePkgName, err := filepath.Rel(root, filepath.Dir(fp))
+				if err != nil {
+					return err
+				}
 
-			importPathFile := path.Join(moduleName, filePkgName)
-			importPath := path.Join(moduleName, pkgName)
+				importPath = path.Join(moduleName, filePkgName)
+			}
 
 			pkg, err := importR.Import(importPath)
 			if err != nil {
@@ -161,7 +150,7 @@ func walk(root, moduleName string) (map[string]PackageDesc, error) {
 
 				interfaceDesc.Methods = append(interfaceDesc.Methods, method)
 
-				for _, imp := range getMethodImports(method, importPathFile) {
+				for _, imp := range getMethodImports(method, packageDesc.PkgPath) {
 					packageDesc.Imports[imp] = struct{}{}
 				}
 			}

mod.go

@@ -5,21 +5,18 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"os"
 	"os/exec"
-
-	"golang.org/x/mod/modfile"
 )
 
 type modInfo struct {
-	Path      string `json:"Path"`
-	Dir       string `json:"Dir"`
-	GoMod     string `json:"GoMod"`
+	Path      string `json:"Path"`  // module name
+	Dir       string `json:"Dir"`   // absolute path to the module
+	GoMod     string `json:"GoMod"` // absolute path to the go.mod
 	GoVersion string `json:"GoVersion"`
 	Main      bool   `json:"Main"`
 }
 
-func getModulePath(dir string) (string, error) {
+func getModuleInfo(dir string) (modInfo, error) {
 	// https://github.com/golang/go/issues/44753#issuecomment-790089020
 	cmd := exec.Command("go", "list", "-m", "-json")
 	if dir != "" {
@@ -28,32 +25,18 @@ func getModulePath(dir string) (string, error) {
 
 	raw, err := cmd.CombinedOutput()
 	if err != nil {
-		return "", fmt.Errorf("command go list: %w: %s", err, string(raw))
+		return modInfo{}, fmt.Errorf("command go list: %w: %s", err, string(raw))
 	}
 
 	var v modInfo
 	err = json.NewDecoder(bytes.NewBuffer(raw)).Decode(&v)
 	if err != nil {
-		return "", fmt.Errorf("unmarshaling error: %w: %s", err, string(raw))
+		return modInfo{}, fmt.Errorf("unmarshaling error: %w: %s", err, string(raw))
 	}
 
 	if v.GoMod == "" {
-		return "", errors.New("working directory is not part of a module")
-	}
-
-	return v.GoMod, nil
-}
-
-func getModuleName(modulePath string) (string, error) {
-	raw, err := os.ReadFile(modulePath)
-	if err != nil {
-		return "", fmt.Errorf("reading go.mod file: %w", err)
-	}
-
-	modData, err := modfile.Parse("go.mod", raw, nil)
-	if err != nil {
-		return "", fmt.Errorf("parsing go.mod file: %w", err)
+		return modInfo{}, errors.New("working directory is not part of a module")
 	}
 
-	return modData.Module.Mod.String(), nil
+	return v, nil
 }