Add support for generating mocks for generic interfaces

go.mod

@@ -1,19 +1,39 @@
 module github.com/vektra/mockery/v2
 
-go 1.16
+go 1.18
 
 require (
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/pkg/errors v0.9.1
 	github.com/rs/zerolog v1.26.1
-	github.com/spf13/afero v1.8.0 // indirect
 	github.com/spf13/cobra v1.3.0
 	github.com/spf13/viper v1.10.1
 	github.com/stretchr/testify v1.7.0
 	golang.org/x/crypto v0.0.0-20220112180741-5e0467b6c7ce
+	golang.org/x/tools v0.1.10
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/fsnotify/fsnotify v1.5.1 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/magiconair/properties v1.8.5 // indirect
+	github.com/mitchellh/mapstructure v1.4.3 // indirect
+	github.com/pelletier/go-toml v1.9.4 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/spf13/afero v1.8.0 // indirect
+	github.com/spf13/cast v1.4.1 // indirect
+	github.com/spf13/jwalterweatherman v1.1.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/stretchr/objx v0.1.1 // indirect
+	github.com/subosito/gotenv v1.2.0 // indirect
+	golang.org/x/mod v0.6.0-dev.0.20220106191415-9b9b3d81d5e3 // indirect
 	golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 // indirect
 	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
-	golang.org/x/tools v0.1.10
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	gopkg.in/ini.v1 v1.66.3 // indirect
-	gopkg.in/yaml.v2 v2.4.0
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )

go.sum

@@ -197,7 +197,6 @@ github.com/googleapis/gax-go/v2 v2.1.1/go.mod h1:hddJymUZASv3XPyGkUpKj8pPO47Rmb0
 github.com/googleapis/google-cloud-go-testing v0.0.0-20200911160855-bcd43fbb19e8/go.mod h1:dvDLG8qkwmyD9a/MJJN3XJcT3xFxOKAvTZGvuZmac9g=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
 github.com/hashicorp/consul/api v1.11.0/go.mod h1:XjsvQN+RJGWI2TWy1/kqaE16HrR2J/FWgkYjdZQsX9M=
-github.com/hashicorp/consul/api v1.12.0/go.mod h1:6pVBMo0ebnYdt2S3H87XhekM/HHrUoTD2XXb/VrZVy0=
 github.com/hashicorp/consul/sdk v0.8.0/go.mod h1:GBvyrGALthsZObzUGsfgHZQDXjg4lOjagTIwIR1vPms=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
 github.com/hashicorp/go-cleanhttp v0.5.0/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
@@ -317,7 +316,6 @@ github.com/rs/zerolog v1.26.1/go.mod h1:/wSSJWX7lVrsOwlbyTRSOJvqRlc+WjWlfes+CiJ+
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/sagikazarmark/crypt v0.3.0/go.mod h1:uD/D+6UF4SrIR1uGEv7bBNkNqLGqUr43MRiaGWX1Nig=
-github.com/sagikazarmark/crypt v0.4.0/go.mod h1:ALv2SRj7GxYV4HO9elxH9nS6M9gW+xDNxqmyJ6RfDFM=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
@@ -356,7 +354,6 @@ github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/yuin/goldmark v1.4.0/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
-github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 go.etcd.io/etcd/api/v3 v3.5.1/go.mod h1:cbVKeC6lCfl7j/8jBhAK6aIYO9XOjdptoxU/nLQcPvs=
 go.etcd.io/etcd/client/pkg/v3 v3.5.1/go.mod h1:IJHfcCEKxYu1Os13ZdwCwIUTUVGYTSAM3YSwc9/Ac1g=
 go.etcd.io/etcd/client/v2 v2.305.1/go.mod h1:pMEacxZW7o8pg4CrFE7pquyCJJzZvkvdD2RibOCCCGs=
@@ -382,7 +379,6 @@ golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210817164053-32db794688a5/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20211108221036-ceb1ce70b4fa/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.0.0-20211215165025-cf75a172585e/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
 golang.org/x/crypto v0.0.0-20220112180741-5e0467b6c7ce h1:Roh6XWxHFKrPgC/EQhVubSAGQ6Ozk6IdxHSzt1mR0EI=
@@ -468,8 +464,6 @@ golang.org/x/net v0.0.0-20210410081132-afb366fc7cd1/go.mod h1:9tjilg8BloeKEkVJvy
 golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -564,10 +558,8 @@ golang.org/x/sys v0.0.0-20210823070655-63515b42dcdf/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210908233432-aa78b53d3365/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211205182925-97ca703d548d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20211210111614-af8b64212486/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 h1:XfKQ4OlFl8okEOr5UvAqFRVj8pY/4yfcXrddB8qAbU0=
 golang.org/x/sys v0.0.0-20220114195835-da31bd327af9/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -681,7 +673,6 @@ google.golang.org/api v0.57.0/go.mod h1:dVPlbZyBo2/OjBpmvNdpn2GRm6rPy75jyU7bmhdr
 google.golang.org/api v0.59.0/go.mod h1:sT2boj7M9YJxZzgeZqXogmhfmRWDtPzT31xkieUbuZU=
 google.golang.org/api v0.61.0/go.mod h1:xQRti5UdCmoCEqFxcz93fTl338AVqDgyaDRuOZ3hg9I=
 google.golang.org/api v0.62.0/go.mod h1:dKmwPCydfsad4qCH08MSdgWjfHOyfpd4VtDGgRFdavw=
-google.golang.org/api v0.63.0/go.mod h1:gs4ij2ffTRXwuzzgJl/56BdwJaA194ijkfn++9tDuPo=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
 google.golang.org/appengine v1.5.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
@@ -781,7 +772,6 @@ google.golang.org/grpc v1.39.1/go.mod h1:PImNr+rS9TWYb2O4/emRugxiyHZ5JyHW5F+RPnD
 google.golang.org/grpc v1.40.0/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
 google.golang.org/grpc v1.40.1/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=
 google.golang.org/grpc v1.42.0/go.mod h1:k+4IHHFw41K8+bbowsex27ge2rCb65oeWqe4jJ590SU=
-google.golang.org/grpc v1.43.0/go.mod h1:k+4IHHFw41K8+bbowsex27ge2rCb65oeWqe4jJ590SU=
 google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.1.0/go.mod h1:6Kw0yEErY5E/yWrBtf03jp27GLLJujG4z/JK95pnjjw=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=

pkg/fixtures/generic.go

@@ -0,0 +1,21 @@
+package test
+
+type Constraint interface {
+	int
+}
+
+type Generic[T Constraint] interface {
+	Get() T
+}
+
+type GenericAny[T any] interface {
+	Get() T
+}
+
+type GenericComparable[T comparable] interface {
+	Get() T
+}
+
+type Embedded interface {
+	Generic[int]
+}

pkg/generator.go

@@ -71,6 +71,20 @@ func (g *Generator) populateImports(ctx context.Context) {
 
 	log.Debug().Msgf("populating imports")
 
+	// imports from generic type constraints
+	if tParams := g.iface.NamedType.TypeParams(); tParams != nil && tParams.Len() > 0 {
+		for i := 0; i < tParams.Len(); i++ {
+			g.renderType(ctx, tParams.At(i).Constraint())
+		}
+	}
+
+	// imports from type arguments
+	if tArgs := g.iface.NamedType.TypeArgs(); tArgs != nil && tArgs.Len() > 0 {
+		for i := 0; i < tArgs.Len(); i++ {
+			g.renderType(ctx, tArgs.At(i))
+		}
+	}
+
 	for _, method := range g.iface.Methods() {
 		ftype := method.Signature
 		g.addImportsFromTuple(ctx, ftype.Params())
@@ -88,6 +102,13 @@ func (g *Generator) addImportsFromTuple(ctx context.Context, list *types.Tuple)
 	}
 }
 
+func (g *Generator) addPackageScopedType(ctx context.Context, o *types.TypeName) string {
+	if o.Pkg() == nil || o.Pkg().Name() == "main" || (!g.KeepTree && g.InPackage && o.Pkg() == g.iface.Pkg) {
+		return o.Name()
+	}
+	return g.addPackageImport(ctx, o.Pkg()) + "." + o.Name()
+}
+
 func (g *Generator) addPackageImport(ctx context.Context, pkg *types.Package) string {
 	return g.addPackageImportWithName(ctx, pkg.Path(), pkg.Name())
 }
@@ -231,6 +252,36 @@ func (g *Generator) mockName() string {
 	return g.maybeMakeNameExported(g.iface.Name, g.Exported)
 }
 
+func (g *Generator) typeConstraints(ctx context.Context) string {
+	tp := g.iface.NamedType.TypeParams()
+	if tp == nil || tp.Len() == 0 {
+		return ""
+	}
+	qualifiedParams := make([]string, 0, tp.Len())
+	for i := 0; i < tp.Len(); i++ {
+		param := tp.At(i)
+		switch constraint := param.Constraint().(type) {
+		case *types.Named:
+			qualifiedParams = append(qualifiedParams, fmt.Sprintf("%s %s", param.String(), g.addPackageScopedType(ctx, constraint.Obj())))
+		case *types.Interface:
+			qualifiedParams = append(qualifiedParams, fmt.Sprintf("%s %s", param.String(), constraint.String()))
+		}
+	}
+	return fmt.Sprintf("[%s]", strings.Join(qualifiedParams, ", "))
+}
+
+func (g *Generator) typeParams() string {
+	tp := g.iface.NamedType.TypeParams()
+	if tp == nil || tp.Len() == 0 {
+		return ""
+	}
+	params := make([]string, 0, tp.Len())
+	for i := 0; i < tp.Len(); i++ {
+		params = append(params, tp.At(i).String())
+	}
+	return fmt.Sprintf("[%s]", strings.Join(params, ", "))
+}
+
 func (g *Generator) expecterName() string {
 	return g.mockName() + "_Expecter"
 }
@@ -335,11 +386,12 @@ type namer interface {
 func (g *Generator) renderType(ctx context.Context, typ types.Type) string {
 	switch t := typ.(type) {
 	case *types.Named:
-		o := t.Obj()
-		if o.Pkg() == nil || o.Pkg().Name() == "main" || (!g.KeepTree && g.InPackage && o.Pkg() == g.iface.Pkg) {
-			return o.Name()
+		return g.addPackageScopedType(ctx, t.Obj())
+	case *types.TypeParam:
+		if t.Constraint() != nil {
+			return t.Obj().Name()
 		}
-		return g.addPackageImport(ctx, o.Pkg()) + "." + o.Name()
+		return g.addPackageScopedType(ctx, t.Obj())
 	case *types.Basic:
 		if t.Kind() == types.UnsafePointer {
 			return "unsafe.Pointer"
@@ -512,7 +564,7 @@ func (g *Generator) Generate(ctx context.Context) error {
 	)
 
 	g.printf(
-		"type %s struct {\n\tmock.Mock\n}\n\n", g.mockName(),
+		"type %s%s struct {\n\tmock.Mock\n}\n\n", g.mockName(), g.typeConstraints(ctx),
 	)
 
 	if g.WithExpecter {
@@ -541,7 +593,7 @@ func (g *Generator) Generate(ctx context.Context) error {
 			)
 		}
 		g.printf(
-			"func (_m *%s) %s(%s) ", g.mockName(), fname,
+			"func (_m *%s%s) %s(%s) ", g.mockName(), g.typeParams(), fname,
 			strings.Join(params.Params, ", "),
 		)
 
@@ -612,7 +664,7 @@ func (g *Generator) Generate(ctx context.Context) error {
 		}
 	}
 
-	g.generateConstructor()
+	g.generateConstructor(ctx)
 
 	return nil
 }
@@ -712,16 +764,17 @@ func (_c *{{.CallStruct}}) Return({{range .Returns.Params}}{{.}},{{end}}) *{{.Ca
 `)
 }
 
-func (g *Generator) generateConstructor() {
+func (g *Generator) generateConstructor(ctx context.Context) {
 	const constructorTemplate = `
 type {{ .ConstructorTestingInterfaceName }} interface {
 	mock.TestingT
 	Cleanup(func())
 }
 
 // {{ .ConstructorName }} creates a new instance of {{ .MockName }}. It also registers a testing interface on the mock and a cleanup function to assert the mocks expectations.
-func {{ .ConstructorName }}(t {{ .ConstructorTestingInterfaceName }}) *{{ .MockName }} {
+func {{ .ConstructorName }}{{ .TypeConstraint }}(t {{ .ConstructorTestingInterfaceName }}) *{{ .MockName }}{{ .TypeParams }} {
 	mock := &{{ .MockName }}{}
+
 	mock.Mock.Test(t)
 
 	t.Cleanup(func() { mock.AssertExpectations(t) })
@@ -736,10 +789,14 @@ func {{ .ConstructorName }}(t {{ .ConstructorTestingInterfaceName }}) *{{ .MockN
 		ConstructorName                 string
 		ConstructorTestingInterfaceName string
 		MockName                        string
+		TypeConstraint                  string
+		TypeParams                      string
 	}{
 		ConstructorName:                 constructorName,
 		ConstructorTestingInterfaceName: constructorName + "T",
 		MockName:                        mockName,
+		TypeConstraint:                  g.typeConstraints(ctx),
+		TypeParams:                      g.typeParams(),
 	}
 	g.printTemplate(data, constructorTemplate)
 }