support imported type aliases

Go 1.23 changed how go/types handles type aliases, which breaks code generation if you use a package that has an alias type (example: https://pkg.go.dev/github.com/golang/[email protected]/ptypes/timestamp#Timestamp). These were getting generated as just the unqualified name, without the package. If you used a previous version of Go, it meant that if that aliased type was in an internal package we'd try to import the internal package instead, resulting in a compilation error.

Add a switch to handle that case, and bump the go.mod version to support using types.Alias.

Author: reillywatson

go.mod

@@ -1,6 +1,6 @@
 module github.com/matryer/moq
 
-go 1.22.5
+go 1.23
 
 require (
 	github.com/pmezard/go-difflib v1.0.0

internal/registry/method_scope.go

@@ -90,6 +90,18 @@ func (m MethodScope) populateImports(t types.Type, imports map[string]*Package)
 			}
 		}
 
+	case *types.Alias:
+		if pkg := t.Obj().Pkg(); pkg != nil {
+			imports[stripVendorPath(pkg.Path())] = m.registry.AddImport(pkg)
+		}
+		// The imports of a Type with a TypeList must be added to the imports list
+		// For example: Foo[otherpackage.Bar] , must have otherpackage imported
+		if targs := t.TypeArgs(); targs != nil {
+			for i := 0; i < targs.Len(); i++ {
+				m.populateImports(targs.At(i), imports)
+			}
+		}
+
 	case *types.Array:
 		m.populateImports(t.Elem(), imports)
 

pkg/moq/moq_test.go

@@ -664,6 +664,22 @@ func TestImportedPackageWithSameName(t *testing.T) {
 	}
 }
 
+func TestImportedPackageWithTypeAlias(t *testing.T) {
+	m, err := New(Config{SrcDir: "testpackages/typealias"})
+	if err != nil {
+		t.Fatalf("moq.New: %s", err)
+	}
+	var buf bytes.Buffer
+	err = m.Mock(&buf, "Example")
+	if err != nil {
+		t.Errorf("mock error: %s", err)
+	}
+	s := buf.String()
+	if !strings.Contains(s, `a typealiastwo.AliasType`) {
+		t.Error("missing typealiastwo.AliasType")
+	}
+}
+
 func TestParseError(t *testing.T) {
 	_, err := New(Config{SrcDir: "testpackages/_parseerror/service"})
 	if err == nil {

pkg/moq/testpackages/typealias/typealias.go

@@ -0,0 +1,9 @@
+package typealias
+
+import (
+	"github.com/matryer/moq/pkg/moq/testpackages/typealiastwo"
+)
+
+type Example interface {
+	Do(a typealiastwo.AliasType) error
+}

pkg/moq/testpackages/typealiastwo/internal/typealiasinternal/typealiasinternal.go

@@ -0,0 +1,6 @@
+package typealiasinternal
+
+// we shouldn't be able to import this type directly, you need to use the alias in the parent package
+type MyInternalType struct {
+	Foo int
+}

pkg/moq/testpackages/typealiastwo/typealiastwo.go

@@ -0,0 +1,5 @@
+package typealiastwo
+
+import "github.com/matryer/moq/pkg/moq/testpackages/typealiastwo/internal/typealiasinternal"
+
+type AliasType = typealiasinternal.MyInternalType