feat: support method provider

Change-Id: I04341c6de67ab2f75bf5da0957ac502f4f5b9ae8

cmd/wire/main_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func TestMethodProvider(t *testing.T) {
+	/*
+		// Support type's method as provider, for example:
+
+		func InitDog() *animals.Dog {
+			panic(wire.Build(
+				animals.NewAnimals,
+				(*animals.Animals).NewDog, // pointer receiver method
+			))
+		}
+
+		func InitCat() *animals.Cat {
+			panic(wire.Build(
+				wire.Value(animals.Animals{}),
+				animals.Animals.NewCat, // struct receiver method
+			))
+		}
+	*/
+	_, b, _, _ := runtime.Caller(0)
+	wireRepoPath := filepath.Dir(filepath.Dir(filepath.Dir(b)))
+	_ = os.Chdir(filepath.Join(wireRepoPath, "tests", "method_provider"))
+	cmd := &genCmd{}
+	code := int(cmd.Execute(context.Background(), flag.CommandLine))
+	if code != 0 {
+		t.Fatal(code)
+	}
+}

internal/wire/parse.go

@@ -659,14 +659,21 @@ 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
-		}
-		if _, ok := info.ObjectOf(pkgName).(*types.PkgName); !ok {
-			return nil
+		switch value := expr.X.(type) {
+		case *ast.ParenExpr, *ast.SelectorExpr:
+			if selection, ok := info.Selections[expr]; !ok {
+				return nil
+			} else {
+				return selection.Obj()
+			}
+		case *ast.Ident:
+			pkgName := value
+			if _, ok := info.ObjectOf(pkgName).(*types.PkgName); !ok {
+				return nil
+			}
+			return info.ObjectOf(expr.Sel)
 		}
-		return info.ObjectOf(expr.Sel)
+		return nil
 	default:
 		return nil
 	}
@@ -701,6 +708,17 @@ func processFuncProvider(fset *token.FileSet, fn *types.Func) (*Provider, []erro
 			}
 		}
 	}
+	if recv := sig.Recv(); recv != nil {
+		switch typ := recv.Type().(type) {
+		case *types.Pointer:
+			elem := typ.Elem().(*types.Named)
+			provider.Name = fmt.Sprintf("(*%s).%s", elem.Obj().Name(), fn.Name())
+			provider.Args = append([]ProviderInput{{Type: typ}}, provider.Args...)
+		case *types.Named:
+			provider.Name = fmt.Sprintf("(%s).%s", typ.Obj().Name(), fn.Name())
+			provider.Args = append([]ProviderInput{{Type: typ}}, provider.Args...)
+		}
+	}
 	return provider, nil
 }
 

internal/wire/wire.go

@@ -523,6 +523,11 @@ func (g *gen) qualifiedID(pkgName, pkgPath, sym string) string {
 	if name == "" {
 		return sym
 	}
+	if strings.HasPrefix(sym, "(*") {
+		return sym[:2] + name + "." + sym[2:]
+	} else if strings.HasPrefix(sym, "(") {
+		return sym[:1] + name + "." + sym[1:]
+	}
 	return name + "." + sym
 }
 

tests/method_provider/animals/animals.go

@@ -0,0 +1,18 @@
+package animals
+
+type Dog struct{}
+type Cat struct{}
+
+type Animals struct{}
+
+func (f *Animals) NewDog() *Dog {
+	return &Dog{}
+}
+
+func (Animals) NewCat() *Cat {
+	return &Cat{}
+}
+
+func NewAnimals() *Animals {
+	return &Animals{}
+}

tests/method_provider/wire.go

@@ -0,0 +1,23 @@
+//+build wireinject
+//go:generate wire
+
+package method_provider
+
+import (
+	"github.com/google/wire"
+	"github.com/google/wire/tests/method_provider/animals"
+)
+
+func InitDog() *animals.Dog {
+	panic(wire.Build(
+		animals.NewAnimals,
+		(*animals.Animals).NewDog,
+	))
+}
+
+func InitCat() *animals.Cat {
+	panic(wire.Build(
+		wire.Value(animals.Animals{}),
+		animals.Animals.NewCat,
+	))
+}