add test

mockgen/tests/vendor_dep/README.md

@@ -0,0 +1,2 @@
+Test for [Issue#4](https://github.com/golang/mock/issues/4).
+Also see discussion on [#28](https://github.com/golang/mock/pull/28).

mockgen/tests/vendor_dep/doc.go

@@ -0,0 +1,3 @@
+package vendor_dep
+
+//go:generate mockgen -package vendor_dep -destination mock.go github.com/golang/mock/mockgen/tests/vendor_dep VendorsDep

mockgen/tests/vendor_dep/vendor/a/a.go

@@ -0,0 +1,10 @@
+package a
+
+type Ifc interface {
+	A(string) string
+	B(int) int
+	C(chan int) chan int
+	D(interface{})
+	E(map[string]interface{})
+	F([]float64)
+}

mockgen/tests/vendor_dep/vendor_dep.go

@@ -0,0 +1,7 @@
+package vendor_dep
+
+import "a"
+
+type VendorsDep interface {
+	Foo() a.Ifc
+}