add support for generics for source mode (golang#640)

Updates: golang#621

.github/workflows/test.yaml

@@ -37,10 +37,16 @@ jobs:
         ./ci/test.sh
         ./ci/check_panic_handling.sh
 
-    - name: Run Go tests
+    - name: Run Go tests all
+      if: ${{ startsWith(matrix.go-version, '1.18') }}
       run: |
         for i in $(find $PWD -name go.mod); do
           pushd $(dirname $i)
           go test ./...
           popd
         done 
+
+    - name: Run Go tests some
+      if: ${{ startsWith(matrix.go-version, '1.18') == false }}
+      run: |
+          go test ./...

mockgen/generic_go118.go

@@ -0,0 +1,88 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build go1.18
+// +build go1.18
+
+package main
+
+import (
+	"go/ast"
+	"strings"
+
+	"github.com/golang/mock/mockgen/model"
+)
+
+func getTypeSpecTypeParams(ts *ast.TypeSpec) []*ast.Field {
+	if ts == nil || ts.TypeParams == nil {
+		return nil
+	}
+	return ts.TypeParams.List
+}
+
+func (p *fileParser) parseGenericType(pkg string, typ ast.Expr, tps map[string]bool) (model.Type, error) {
+	switch v := typ.(type) {
+	case *ast.IndexExpr:
+		m, err := p.parseType(pkg, v.X, tps)
+		if err != nil {
+			return nil, err
+		}
+		nm, ok := m.(*model.NamedType)
+		if !ok {
+			return m, nil
+		}
+		t, err := p.parseType(pkg, v.Index, tps)
+		if err != nil {
+			return nil, err
+		}
+		nm.TypeParams = &model.TypeParametersType{TypeParameters: []model.Type{t}}
+		return m, nil
+	case *ast.IndexListExpr:
+		m, err := p.parseType(pkg, v.X, tps)
+		if err != nil {
+			return nil, err
+		}
+		nm, ok := m.(*model.NamedType)
+		if !ok {
+			return m, nil
+		}
+		var ts []model.Type
+		for _, expr := range v.Indices {
+			t, err := p.parseType(pkg, expr, tps)
+			if err != nil {
+				return nil, err
+			}
+			ts = append(ts, t)
+		}
+		nm.TypeParams = &model.TypeParametersType{TypeParameters: ts}
+		return m, nil
+	}
+	return nil, nil
+}
+
+func getIdentTypeParams(decl interface{}) string {
+	if decl == nil {
+		return ""
+	}
+	ts, ok := decl.(*ast.TypeSpec)
+	if !ok {
+		return ""
+	}
+	if ts.TypeParams == nil || len(ts.TypeParams.List) == 0 {
+		return ""
+	}
+	var sb strings.Builder
+	sb.WriteString("[")
+	for i, v := range ts.TypeParams.List {
+		if i != 0 {
+			sb.WriteString(", ")
+		}
+		sb.WriteString(v.Names[0].Name)
+	}
+	sb.WriteString("]")
+	return sb.String()
+}

mockgen/generic_notgo118.go

@@ -0,0 +1,36 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !go1.18
+// +build !go1.18
+
+package main
+
+import (
+	"go/ast"
+
+	"github.com/golang/mock/mockgen/model"
+)
+
+func getTypeSpecTypeParams(ts *ast.TypeSpec) []*ast.Field {
+	return nil
+}
+
+func (p *fileParser) parseGenericType(pkg string, typ ast.Expr, tps map[string]bool) (model.Type, error) {
+	return nil, nil
+}
+
+func getIdentTypeParams(decl interface{}) string {
+	return ""
+}

mockgen/internal/tests/generics/external.go

@@ -0,0 +1,21 @@
+package generics
+
+import (
+	"github.com/golang/mock/mockgen/internal/tests/generics/other"
+	"golang.org/x/exp/constraints"
+)
+
+//go:generate mockgen --source=external.go --destination=source/mock_external_test.go --package source
+
+type ExternalConstraint[I constraints.Integer, F constraints.Float] interface {
+	One(string) string
+	Two(I) string
+	Three(I) F
+	Four(I) Foo[I, F]
+	Five(I) Baz[F]
+	Six(I) *Baz[F]
+	Seven(I) other.One[I]
+	Eight(F) other.Two[I, F]
+	Nine(Iface[I])
+	Ten(*I)
+}

mockgen/internal/tests/generics/generics.go

@@ -0,0 +1,40 @@
+package generics
+
+import "github.com/golang/mock/mockgen/internal/tests/generics/other"
+
+//go:generate mockgen --source=generics.go --destination=source/mock_generics_test.go --package source
+////go:generate mockgen --destination=reflect/mock_test.go --package reflect . Bar,Bar2
+
+type Bar[T any, R any] interface {
+	One(string) string
+	Two(T) string
+	Three(T) R
+	Four(T) Foo[T, R]
+	Five(T) Baz[T]
+	Six(T) *Baz[T]
+	Seven(T) other.One[T]
+	Eight(T) other.Two[T, R]
+	Nine(Iface[T])
+	Ten(*T)
+	Eleven() (*other.One[T], error)
+	Twelve() (*other.Two[T, R], error)
+	Thirteen() (Baz[StructType], error)
+	Fourteen() (*Foo[StructType, StructType2], error)
+	Fifteen() (Iface[StructType], error)
+	Sixteen() (Baz[other.Three], error)
+	Seventeen() (*Foo[other.Three, other.Four], error)
+	Eighteen() (Iface[*other.Five], error)
+	Nineteen() AliasType
+}
+
+type Foo[T any, R any] struct{}
+
+type Baz[T any] struct{}
+
+type Iface[T any] interface{}
+
+type StructType struct{}
+
+type StructType2 struct{}
+
+type AliasType Baz[other.Three]

mockgen/internal/tests/generics/go.mod

@@ -0,0 +1,10 @@
+module github.com/golang/mock/mockgen/internal/tests/generics
+
+go 1.18
+
+require (
+	github.com/golang/mock v1.6.0
+	golang.org/x/exp v0.0.0-20220428152302-39d4317da171
+)
+
+replace github.com/golang/mock => ../../../..

mockgen/internal/tests/generics/go.sum

@@ -0,0 +1,26 @@
+github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/exp v0.0.0-20220428152302-39d4317da171 h1:TfdoLivD44QwvssI9Sv1xwa5DcL5XQr4au4sZ2F2NV4=
+golang.org/x/exp v0.0.0-20220428152302-39d4317da171/go.mod h1:lgLbSvA5ygNOMpwM/9anMpWVlVJ7Z+cHWq/eFuinpGE=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.8/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

mockgen/internal/tests/generics/other/other.go

@@ -0,0 +1,11 @@
+package other
+
+type One[T any] struct{}
+
+type Two[T any, R any] struct{}
+
+type Three struct{}
+
+type Four struct{}
+
+type Five interface{}