internal/wire: add method providers support

internal/wire/parse.go

@@ -425,6 +425,7 @@ type objectCache struct {
 
 type objRef struct {
 	importPath string
+	recvType   string
 	name       string
 }
 
@@ -493,6 +494,10 @@ func (oc *objectCache) get(obj types.Object) (val interface{}, errs []error) {
 		pkgPath := obj.Pkg().Path()
 		return oc.processExpr(oc.packages[pkgPath].TypesInfo, pkgPath, spec.Values[i], obj.Name())
 	case *types.Func:
+		sig := obj.Type().(*types.Signature)
+		if recv := sig.Recv(); recv != nil {
+			ref.recvType = recv.Type().String()
+		}
 		return processFuncProvider(oc.fset, obj)
 	default:
 		return nil, []error{fmt.Errorf("%v is not a provider or a provider set", obj)}
@@ -659,14 +664,42 @@ func qualifiedIdentObject(info *types.Info, expr ast.Expr) types.Object {
 	case *ast.Ident:
 		return info.ObjectOf(expr)
 	case *ast.SelectorExpr:
-		pkgName, ok := expr.X.(*ast.Ident)
-		if !ok {
-			return nil
+		x := astutil.Unparen(expr.X)
+		if star, ok := x.(*ast.StarExpr); ok {
+			x = star.X
 		}
-		if _, ok := info.ObjectOf(pkgName).(*types.PkgName); !ok {
+		switch x := x.(type) {
+		case *ast.Ident:
+			switch obj := info.ObjectOf(x); obj.(type) {
+			case *types.PkgName:
+			case *types.TypeName:
+				named, ok := obj.Type().(*types.Named)
+				if !ok {
+					return nil
+				}
+
+				t := named.Underlying()
+				if ptr, ok := t.(*types.Pointer); ok {
+					t = ptr.Elem()
+				}
+			default:
+				return nil
+			}
+
+			return info.ObjectOf(expr.Sel)
+		case *ast.SelectorExpr:
+			pkgName, ok := x.X.(*ast.Ident)
+			if !ok {
+				return nil
+			}
+			if _, ok := info.ObjectOf(pkgName).(*types.PkgName); !ok {
+				return nil
+			}
+			return info.ObjectOf(expr.Sel)
+		default:
 			return nil
 		}
-		return info.ObjectOf(expr.Sel)
+
 	default:
 		return nil
 	}
@@ -680,7 +713,17 @@ func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, []erro
 	if err != nil {
 		return nil, []error{notePosition(fset.Position(fpos), fmt.Errorf("wrong signature for provider %s: %v", fn.Name(), err))}
 	}
+
 	params := sig.Params()
+	if recv := sig.Recv(); recv != nil {
+		newParams := make([]*types.Var, params.Len()+1)
+		newParams[0] = recv
+		for i := 0; i < params.Len(); i++ {
+			newParams[i+1] = params.At(i)
+		}
+		params = types.NewTuple(newParams...)
+	}
+
 	provider := &Provider{
 		Pkg:        fn.Pkg(),
 		Name:       fn.Name(),
@@ -691,6 +734,7 @@ func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, []erro
 		HasCleanup: providerSig.cleanup,
 		HasErr:     providerSig.err,
 	}
+
 	for i := 0; i < params.Len(); i++ {
 		provider.Args[i] = ProviderInput{
 			Type: params.At(i).Type(),

internal/wire/testdata/MethodProvider/foo/foo.go

@@ -0,0 +1,74 @@
+// Copyright 2018 The Wire Authors
+//
+// 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
+//
+//     https://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.
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/google/wire"
+)
+
+func main() {
+	fmt.Println(injectFooBar())
+}
+
+type (
+	Foo    int
+	FooBar int
+	Baz    int
+)
+
+var Set = wire.NewSet(
+	newFooProvider,
+	fooProvider.provideFoo,
+	newFooBarProvider,
+	(*fooBarProvider).provideFooBar,
+	newBazProvider,
+	bazProvider.provideBaz,
+)
+
+type fooProvider struct{}
+
+func newFooProvider() fooProvider {
+	return fooProvider{}
+}
+
+func (f fooProvider) provideFoo() Foo {
+	return 40
+}
+
+type fooBarProvider struct{}
+
+func newFooBarProvider() *fooBarProvider {
+	return &fooBarProvider{}
+}
+
+func (*fooBarProvider) provideFooBar(foo Foo) FooBar {
+	return FooBar(foo) + 1
+}
+
+type bazProvider interface {
+	provideBaz(f FooBar) Baz
+}
+
+func newBazProvider() bazProvider {
+	return bazProviderImpl{}
+}
+
+type bazProviderImpl struct{}
+
+func (bazProviderImpl) provideBaz(fooBar FooBar) Baz {
+	return Baz(fooBar) + 1
+}

internal/wire/testdata/MethodProvider/foo/wire.go

@@ -0,0 +1,27 @@
+// Copyright 2018 The Wire Authors
+//
+// 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
+//
+//     https://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 wireinject
+// +build wireinject
+
+package main
+
+import (
+	"github.com/google/wire"
+)
+
+func injectFooBar() Baz {
+	wire.Build(Set)
+	return 0
+}

internal/wire/testdata/MethodProvider/pkg

@@ -0,0 +1 @@
+example.com/foo

internal/wire/testdata/MethodProvider/want/program_out.txt

@@ -0,0 +1 @@
+42