support import shadowing

mockgen/internal/tests/import_shadowing/foo/foo.go

@@ -0,0 +1,3 @@
+package foo
+
+type MyInt int

mockgen/internal/tests/import_shadowing/import.go

@@ -0,0 +1,11 @@
+package import_shadowing
+
+import (
+	"go.uber.org/mock/mockgen/internal/tests/import_shadowing/foo"
+)
+
+//go:generate mockgen -destination mock.go -source import.go -package import_shadowing . Bar
+
+type Bar interface {
+	Hoge(foo string) foo.MyInt
+}

mockgen/mockgen.go

@@ -386,6 +386,23 @@ func (g *generator) Generate(pkg *model.Package, outputPkgName string, outputPac
 			i++
 		}
 
+		isImportShadowing := func() bool {
+			for _, intf := range pkg.Interfaces {
+				for _, m := range intf.Methods {
+					for _, p := range m.In {
+						if p.Name == pkgName {
+							return true
+						}
+					}
+				}
+			}
+			return false
+		}
+
+		if isImportShadowing() {
+			pkgName = base + "Pkg"
+		}
+
 		// Avoid importing package if source pkg == output pkg
 		if pth == pkg.PkgPath && outputPackagePath == pkg.PkgPath {
 			continue
@@ -756,6 +773,7 @@ func (g *generator) getArgNames(m *model.Method, in bool) []string {
 		params = m.Out
 	}
 	argNames := make([]string, len(params))
+
 	for i, p := range params {
 		name := p.Name
 		if name == "" || name == "_" {