Fix transform bug with result type oneof attribute (#3115)

Upgrade to Go 1.19
Remove use of deprecated io/ioutil package

.github/workflows/ci.yml

@@ -7,10 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.18
+    - name: Set up Go 1.19
       uses: actions/setup-go@v3.2.1
       with:
-        go-version: 1.18
+        go-version: 1.19
       id: go
 
     - name: Check out code into the Go module directory
@@ -34,10 +34,10 @@ jobs:
     runs-on: windows-latest
     steps:
 
-    - name: Set up Go 1.18
+    - name: Set up Go 1.19
       uses: actions/setup-go@v3.2.1
       with:
-        go-version: 1.18
+        go-version: 1.19
       id: go
 
     - name: Check out code into the Go module directory

cmd/goa/gen.go

@@ -6,7 +6,6 @@ import (
 	"go/build"
 	"go/parser"
 	"go/token"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -67,7 +66,7 @@ func NewGenerator(cmd string, path, output string) *Generator {
 				}
 			}
 			for _, gof := range pkg.GoFiles {
-				if bs, err := ioutil.ReadFile(gof); err == nil {
+				if bs, err := os.ReadFile(gof); err == nil {
 					if f, err := parser.ParseFile(fset, "", string(bs), parser.ImportsOnly); err == nil {
 						for _, s := range f.Imports {
 							matches := p.FindStringSubmatch(s.Path.Value)
@@ -106,7 +105,7 @@ func (g *Generator) Write(debug bool) error {
 		if cwd, err := os.Getwd(); err != nil {
 			wd = cwd
 		}
-		tmp, err := ioutil.TempDir(wd, "goa")
+		tmp, err := os.MkdirTemp(wd, "goa")
 		if err != nil {
 			return err
 		}

codegen/file.go

@@ -9,7 +9,6 @@ import (
 	"go/scanner"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -138,7 +137,7 @@ func finalizeGoSource(path string) error {
 	fset := token.NewFileSet()
 	file, err := parser.ParseFile(fset, path, nil, parser.ParseComments)
 	if err != nil {
-		content, _ := ioutil.ReadFile(path)
+		content, _ := os.ReadFile(path)
 		var buf bytes.Buffer
 		scanner.PrintError(&buf, err)
 		return fmt.Errorf("%s\n========\nContent:\n%s", buf.String(), content)
@@ -169,7 +168,7 @@ func finalizeGoSource(path string) error {
 	w.Close()
 
 	// Format code using goimport standard
-	bs, err := ioutil.ReadFile(path)
+	bs, err := os.ReadFile(path)
 	if err != nil {
 		return err
 	}
@@ -181,5 +180,5 @@ func finalizeGoSource(path string) error {
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(path, bs, os.ModePerm)
+	return os.WriteFile(path, bs, os.ModePerm)
 }

codegen/generator/generate.go

@@ -1,7 +1,6 @@
 package generator
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -36,7 +35,7 @@ func Generate(dir, cmd string) (outputs []string, err1 error) {
 		}
 
 		// We create a temporary Go file to make sure the directory is a valid Go package
-		dummy, err := ioutil.TempFile(path, "temp.*.go")
+		dummy, err := os.CreateTemp(path, "temp.*.go")
 		if err != nil {
 			return nil, err
 		}

codegen/go_transform.go

@@ -348,6 +348,10 @@ func transformMap(source, target *expr.Map, sourceVar, targetVar string, newVar
 }
 
 // transformUnion generates Go code to transform source union to target union.
+//
+// Note: transport to/from service transforms are always object to union or
+// union to object. The only case a transform is union to union is when
+// converting a projected type from/to a service type.
 func transformUnion(source, target *expr.AttributeExpr, sourceVar, targetVar string, newVar bool, ta *TransformAttrs) (string, error) {
 	if expr.IsObject(target.Type) {
 		return transformUnionToObject(source, target, sourceVar, targetVar, newVar, ta)
@@ -365,7 +369,7 @@ func transformUnion(source, target *expr.AttributeExpr, sourceVar, targetVar str
 	}
 	sourceTypeRefs := make([]string, len(srcUnion.Values))
 	for i, st := range srcUnion.Values {
-		sourceTypeRefs[i] = ta.TargetCtx.Scope.Ref(st.Attribute, ta.TargetCtx.Pkg(st.Attribute))
+		sourceTypeRefs[i] = ta.TargetCtx.Scope.Ref(st.Attribute, ta.SourceCtx.Pkg(st.Attribute))
 	}
 	targetTypeNames := make([]string, len(tgtUnion.Values))
 	for i, tt := range tgtUnion.Values {
@@ -661,8 +665,7 @@ for key, val := range {{ .SourceVar }} {
 {{ end }}switch actual := {{ .SourceVar }}.(type) {
 	{{- range $i, $ref := .SourceTypeRefs }}
 	case {{ $ref }}:
-		{{ transformAttribute (index $.SourceTypes $i).Attribute (index $.TargetTypes $i).Attribute "actual" "val" true $.TransformAttrs -}}
-		{{ $.TargetVar }} = {{ $.TargetTypeName }}{ Value: val }
+		{{- transformAttribute (index $.SourceTypes $i).Attribute (index $.TargetTypes $i).Attribute "actual" $.TargetVar false $.TransformAttrs -}}
 	{{- end }}
 }
 `

codegen/go_transform_union_test.go

@@ -13,12 +13,13 @@ func TestGoTransformUnion(t *testing.T) {
 		scope = NewNameScope()
 
 		// types to test
-		unionString    = root.UserType("Container").Attribute().Find("UnionString").Find("UnionString")
-		unionString2   = root.UserType("Container").Attribute().Find("UnionString2").Find("UnionString2")
-		unionStringInt = root.UserType("Container").Attribute().Find("UnionStringInt").Find("UnionStringInt")
-		unionSomeType  = root.UserType("Container").Attribute().Find("UnionSomeType").Find("UnionSomeType")
-		userType       = &expr.AttributeExpr{Type: root.UserType("UnionUserType")}
-		defaultCtx     = NewAttributeContext(false, false, true, "", scope)
+		unionString     = root.UserType("Container").Attribute().Find("UnionString").Find("UnionString")
+		unionString2    = root.UserType("Container").Attribute().Find("UnionString2").Find("UnionString2")
+		unionStringInt  = root.UserType("Container").Attribute().Find("UnionStringInt").Find("UnionStringInt")
+		unionStringInt2 = root.UserType("Container").Attribute().Find("UnionStringInt2").Find("UnionStringInt2")
+		unionSomeType   = root.UserType("Container").Attribute().Find("UnionSomeType").Find("UnionSomeType")
+		userType        = &expr.AttributeExpr{Type: root.UserType("UnionUserType")}
+		defaultCtx      = NewAttributeContext(false, false, true, "", scope)
 	)
 	tc := []struct {
 		Name     string
@@ -27,6 +28,7 @@ func TestGoTransformUnion(t *testing.T) {
 		Expected string
 	}{
 		{"UnionString to UnionString2", unionString, unionString2, unionToUnionCode},
+		{"UnionStringInt to UnionStringInt2", unionStringInt, unionStringInt2, unionMultiToUnionMultiCode},
 
 		{"UnionString to User Type", unionString, userType, unionStringToUserTypeCode},
 		{"UnionStringInt to User Type", unionStringInt, userType, unionStringIntToUserTypeCode},
@@ -89,8 +91,21 @@ const unionToUnionCode = `func transform() {
 	var target *UnionString2
 	switch actual := source.(type) {
 	case UnionStringString:
-		val := UnionString2String(actual)
-		target = UnionString2{Value: val}
+		target = UnionString2String(actual)
+
+	}
+}
+`
+
+const unionMultiToUnionMultiCode = `func transform() {
+	var target *UnionStringInt2
+	switch actual := source.(type) {
+	case UnionStringIntString:
+		target = UnionStringInt2String(actual)
+
+	case UnionStringIntInt:
+		target = UnionStringInt2Int(actual)
+
 	}
 }
 `

codegen/service/service_data.go

@@ -78,6 +78,8 @@ type (
 		// projectedTypes lists the types which uses pointers for all fields to
 		// define view specific validation logic.
 		projectedTypes []*ProjectedTypeData
+		// union methods that need to be defined in views package.
+		viewedUnionMethods []*UnionValueMethodData
 		// viewedResultTypes lists all the viewed method result types.
 		viewedResultTypes []*ViewedResultTypeData
 		// unionValueMethods lists the methods used to define union types.
@@ -538,19 +540,20 @@ func (s SchemesData) Append(d *SchemeData) SchemesData {
 // It records the user types needed by the service definition in userTypes.
 func (d ServicesData) analyze(service *expr.ServiceExpr) *Data {
 	var (
-		scope      *codegen.NameScope
-		viewScope  *codegen.NameScope
-		pkgName    string
-		viewspkg   string
-		types      []*UserTypeData
-		errTypes   []*UserTypeData
-		errorInits []*ErrorInitData
-		projTypes  []*ProjectedTypeData
-		viewedRTs  []*ViewedResultTypeData
-		seenErrors map[string]struct{}
-		seen       map[string]struct{}
-		seenProj   map[string]*ProjectedTypeData
-		seenViewed map[string]*ViewedResultTypeData
+		scope            *codegen.NameScope
+		viewScope        *codegen.NameScope
+		pkgName          string
+		viewspkg         string
+		types            []*UserTypeData
+		errTypes         []*UserTypeData
+		errorInits       []*ErrorInitData
+		projTypes        []*ProjectedTypeData
+		viewedUnionMeths []*UnionValueMethodData
+		viewedRTs        []*ViewedResultTypeData
+		seenErrors       map[string]struct{}
+		seen             map[string]struct{}
+		seenProj         map[string]*ProjectedTypeData
+		seenViewed       map[string]*ViewedResultTypeData
 	)
 	{
 		scope = codegen.NewNameScope()
@@ -593,7 +596,9 @@ func (d ServicesData) analyze(service *expr.ServiceExpr) *Data {
 			if _, ok := m.Result.Type.(*expr.ResultTypeExpr); ok {
 				// collect projected types for the corresponding result type
 				projected := expr.DupAtt(m.Result)
-				projTypes = append(projTypes, collectProjectedTypes(projected, m.Result, viewspkg, scope, viewScope, seenProj)...)
+				types, umeths := collectProjectedTypes(projected, m.Result, viewspkg, scope, viewScope, seenProj)
+				projTypes = append(projTypes, types...)
+				viewedUnionMeths = append(viewedUnionMeths, umeths...)
 			}
 			for _, er := range m.Errors {
 				recordError(er)
@@ -724,23 +729,24 @@ func (d ServicesData) analyze(service *expr.ServiceExpr) *Data {
 
 	varName := codegen.Goify(service.Name, false)
 	data := &Data{
-		Name:              service.Name,
-		Description:       desc,
-		VarName:           varName,
-		PathName:          codegen.SnakeCase(varName),
-		StructName:        codegen.Goify(service.Name, true),
-		PkgName:           pkgName,
-		ViewsPkg:          viewspkg,
-		Methods:           methods,
-		Schemes:           schemes,
-		Scope:             scope,
-		ViewScope:         viewScope,
-		errorTypes:        errTypes,
-		errorInits:        errorInits,
-		userTypes:         types,
-		projectedTypes:    projTypes,
-		viewedResultTypes: viewedRTs,
-		unionValueMethods: ms,
+		Name:               service.Name,
+		Description:        desc,
+		VarName:            varName,
+		PathName:           codegen.SnakeCase(varName),
+		StructName:         codegen.Goify(service.Name, true),
+		PkgName:            pkgName,
+		ViewsPkg:           viewspkg,
+		Methods:            methods,
+		Schemes:            schemes,
+		Scope:              scope,
+		ViewScope:          viewScope,
+		errorTypes:         errTypes,
+		errorInits:         errorInits,
+		userTypes:          types,
+		projectedTypes:     projTypes,
+		viewedUnionMethods: viewedUnionMeths,
+		viewedResultTypes:  viewedRTs,
+		unionValueMethods:  ms,
 	}
 	d[service.Name] = data
 
@@ -1149,8 +1155,8 @@ func BuildSchemeData(s *expr.SchemeExpr, m *expr.MethodExpr) *SchemeData {
 // make use of views. We need to build projected types for all user types - not
 // just result types - because user types make contain result types and thus may
 // need to be marshalled in different ways depending on the view being used.
-func collectProjectedTypes(projected, att *expr.AttributeExpr, viewspkg string, scope, viewScope *codegen.NameScope, seen map[string]*ProjectedTypeData) (data []*ProjectedTypeData) {
-	collect := func(projected, att *expr.AttributeExpr) []*ProjectedTypeData {
+func collectProjectedTypes(projected, att *expr.AttributeExpr, viewspkg string, scope, viewScope *codegen.NameScope, seen map[string]*ProjectedTypeData) (data []*ProjectedTypeData, umeths []*UnionValueMethodData) {
+	collect := func(projected, att *expr.AttributeExpr) ([]*ProjectedTypeData, []*UnionValueMethodData) {
 		return collectProjectedTypes(projected, att, viewspkg, scope, viewScope, seen)
 	}
 	switch pt := projected.Type.(type) {
@@ -1171,22 +1177,44 @@ func collectProjectedTypes(projected, att *expr.AttributeExpr, viewspkg string,
 		pt.Rename(pt.Name() + "View")
 		// We recurse before building the projected type so that user types within
 		// a projected type is also converted to their respective projected types.
-		types := collect(pt.Attribute(), dt.Attribute())
+		types, ms := collect(pt.Attribute(), dt.Attribute())
 		pd := buildProjectedType(projected, att, viewspkg, scope, viewScope)
 		seen[dt.ID()] = pd
 		data = append(data, pd)
 		data = append(data, types...)
+		umeths = append(umeths, ms...)
 	case *expr.Array:
 		dt := att.Type.(*expr.Array)
-		data = append(data, collect(pt.ElemType, dt.ElemType)...)
+		types, ms := collect(pt.ElemType, dt.ElemType)
+		data = append(data, types...)
+		umeths = append(umeths, ms...)
 	case *expr.Map:
 		dt := att.Type.(*expr.Map)
-		data = append(data, collect(pt.KeyType, dt.KeyType)...)
-		data = append(data, collect(pt.ElemType, dt.ElemType)...)
+		types, ms := collect(pt.KeyType, dt.KeyType)
+		data = append(data, types...)
+		umeths = append(umeths, ms...)
+		types, ms = collect(pt.ElemType, dt.ElemType)
+		data = append(data, types...)
+		umeths = append(umeths, ms...)
 	case *expr.Object:
 		dt := att.Type.(*expr.Object)
 		for _, n := range *pt {
-			data = append(data, collect(n.Attribute, dt.Attribute(n.Name))...)
+			types, ms := collect(n.Attribute, dt.Attribute(n.Name))
+			data = append(data, types...)
+			umeths = append(umeths, ms...)
+		}
+	case *expr.Union:
+		dt := att.Type.(*expr.Union)
+		for i, n := range pt.Values {
+			types, ms := collect(n.Attribute, dt.Values[i].Attribute)
+			data = append(data, types...)
+			umeths = append(umeths, ms...)
+		}
+		for _, nat := range pt.Values {
+			umeths = append(umeths, &UnionValueMethodData{
+				Name:    codegen.UnionValTypeName(pt.Name()),
+				TypeRef: scope.GoTypeRef(nat.Attribute),
+			})
 		}
 	}
 	return

codegen/service/views.go

@@ -49,6 +49,16 @@ func ViewsFile(genpkg string, service *expr.ServiceExpr) *codegen.File {
 			})
 		}
 
+		// Union methods
+		for _, m := range svc.viewedUnionMethods {
+			sections = append(sections, &codegen.SectionTemplate{
+				// addTypeDefSection(pathWithDefault(m.Loc, svcPath), "~"+m.TypeRef+"."+m.Name, &codegen.SectionTemplate{
+				Name:   "viewed-union-value-method",
+				Source: unionValueMethodT,
+				Data:   m,
+			})
+		}
+
 		// generate a map for result types with view name as key and the fields
 		// rendered in the view as value.
 		var (

codegen/testdata/union_dsls.go

@@ -26,6 +26,12 @@ var TestUnionDSL = func() {
 				Attribute("Int", Int)
 			})
 		})
+		UnionStringInt2 = Type("UnionStringInt2", func() {
+			OneOf("UnionStringInt2", func() {
+				Attribute("String", String)
+				Attribute("Int", Int)
+			})
+		})
 		UnionSomeType = Type("UnionSomeType", func() {
 			OneOf("UnionSomeType", func() {
 				Attribute("SomeType", SomeType)
@@ -36,6 +42,7 @@ var TestUnionDSL = func() {
 			Attribute("UnionString", UnionString)
 			Attribute("UnionString2", UnionString2)
 			Attribute("UnionStringInt", UnionStringInt)
+			Attribute("UnionStringInt2", UnionStringInt2)
 			Attribute("UnionSomeType", UnionSomeType)
 		})