From a0e7ed18c2171d82f452f094a20e1606dc20c74a Mon Sep 17 00:00:00 2001
From: eyasy1217 <yuyi4145@gmail.com>
Date: Wed, 10 Jul 2024 22:58:50 +0900
Subject: [PATCH] support import shadowing

---
 .../tests/import_shadowing/foo/foo.go         |  3 +
 .../internal/tests/import_shadowing/import.go | 11 ++++
 .../internal/tests/import_shadowing/mock.go   | 59 +++++++++++++++++++
 mockgen/mockgen.go                            | 14 +++++
 4 files changed, 87 insertions(+)
 create mode 100644 mockgen/internal/tests/import_shadowing/foo/foo.go
 create mode 100644 mockgen/internal/tests/import_shadowing/import.go
 create mode 100644 mockgen/internal/tests/import_shadowing/mock.go

diff --git a/mockgen/internal/tests/import_shadowing/foo/foo.go b/mockgen/internal/tests/import_shadowing/foo/foo.go
new file mode 100644
index 0000000..5dc6dca
--- /dev/null
+++ b/mockgen/internal/tests/import_shadowing/foo/foo.go
@@ -0,0 +1,3 @@
+package foo
+
+type MyInt int
diff --git a/mockgen/internal/tests/import_shadowing/import.go b/mockgen/internal/tests/import_shadowing/import.go
new file mode 100644
index 0000000..01344da
--- /dev/null
+++ b/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
+}
diff --git a/mockgen/internal/tests/import_shadowing/mock.go b/mockgen/internal/tests/import_shadowing/mock.go
new file mode 100644
index 0000000..8c694a7
--- /dev/null
+++ b/mockgen/internal/tests/import_shadowing/mock.go
@@ -0,0 +1,59 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: import.go
+//
+// Generated by this command:
+//
+//	mockgen -destination mock.go -source import.go -package import_shadowing . Bar
+//
+
+// Package import_shadowing is a generated GoMock package.
+package import_shadowing
+
+import (
+	reflect "reflect"
+
+	gomock "go.uber.org/mock/gomock"
+	fooPkg "go.uber.org/mock/mockgen/internal/tests/import_shadowing/foo"
+)
+
+// MockBar is a mock of Bar interface.
+type MockBar struct {
+	ctrl     *gomock.Controller
+	recorder *MockBarMockRecorder
+}
+
+// MockBarMockRecorder is the mock recorder for MockBar.
+type MockBarMockRecorder struct {
+	mock *MockBar
+}
+
+// NewMockBar creates a new mock instance.
+func NewMockBar(ctrl *gomock.Controller) *MockBar {
+	mock := &MockBar{ctrl: ctrl}
+	mock.recorder = &MockBarMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockBar) EXPECT() *MockBarMockRecorder {
+	return m.recorder
+}
+
+// ISGOMOCK indicates that this struct is a gomock mock.
+func (m *MockBar) ISGOMOCK() struct{} {
+	return struct{}{}
+}
+
+// Hoge mocks base method.
+func (m *MockBar) Hoge(foo string) fooPkg.MyInt {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Hoge", foo)
+	ret0, _ := ret[0].(fooPkg.MyInt)
+	return ret0
+}
+
+// Hoge indicates an expected call of Hoge.
+func (mr *MockBarMockRecorder) Hoge(foo any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Hoge", reflect.TypeOf((*MockBar)(nil).Hoge), foo)
+}
diff --git a/mockgen/mockgen.go b/mockgen/mockgen.go
index 5d57868..3d2fc00 100644
--- a/mockgen/mockgen.go
+++ b/mockgen/mockgen.go
@@ -363,6 +363,16 @@ func (g *generator) Generate(pkg *model.Package, outputPkgName string, outputPac
 
 	g.packageMap = make(map[string]string, len(im))
 	localNames := make(map[string]bool, len(im))
+	paramNamesInterfaces := make(map[string]struct{}, 0)
+	for _, intf := range pkg.Interfaces {
+		for _, m := range intf.Methods {
+			for _, i := range m.In {
+				if i.Name != "" {
+					paramNamesInterfaces[i.Name] = struct{}{}
+				}
+			}
+		}
+	}
 	for _, pth := range sortedPaths {
 		base, ok := packagesName[pth]
 		if !ok {
@@ -386,6 +396,10 @@ func (g *generator) Generate(pkg *model.Package, outputPkgName string, outputPac
 			i++
 		}
 
+		if _, isImportShadowing := paramNamesInterfaces[pkgName]; isImportShadowing {
+			pkgName = base + "Pkg"
+		}
+
 		// Avoid importing package if source pkg == output pkg
 		if pth == pkg.PkgPath && outputPackagePath == pkg.PkgPath {
 			continue