feat: support enums in go runtime (#1006)

backend/schema/any.go

@@ -20,3 +20,4 @@ func (*Any) schemaType()              {}
 func (*Any) schemaDecl()              {}
 func (*Any) String() string           { return "Any" }
 func (a *Any) ToProto() proto.Message { return &schemapb.Any{Pos: posToProto(a.Pos)} }
+func (*Any) GetName() string          { return "" }

backend/schema/bool.go

@@ -21,3 +21,4 @@ func (*Bool) schemaType()              {}
 func (*Bool) schemaDecl()              {}
 func (*Bool) String() string           { return "Bool" }
 func (b *Bool) ToProto() proto.Message { return &schemapb.Bool{Pos: posToProto(b.Pos)} }
+func (*Bool) GetName() string          { return "" }

backend/schema/bytes.go

@@ -21,3 +21,4 @@ func (*Bytes) schemaType()              {}
 func (*Bytes) schemaDecl()              {}
 func (*Bytes) String() string           { return "Bytes" }
 func (b *Bytes) ToProto() proto.Message { return &schemapb.Bytes{Pos: posToProto(b.Pos)} }
+func (*Bytes) GetName() string          { return "" }

backend/schema/data.go

@@ -132,6 +132,8 @@ func (d *Data) schemaChildren() []Node {
 	return children
 }
 
+func (d *Data) GetName() string { return d.Name }
+
 func (d *Data) String() string {
 	w := &strings.Builder{}
 	fmt.Fprint(w, encodeComments(d.Comments))

backend/schema/database.go

@@ -35,6 +35,9 @@ func (d *Database) ToProto() proto.Message {
 		Comments: d.Comments,
 	}
 }
+
+func (d *Database) GetName() string { return d.Name }
+
 func DatabaseFromProto(s *schemapb.Database) *Database {
 	return &Database{
 		Pos:      posFromProto(s.Pos),

backend/schema/enum.go

@@ -51,6 +51,8 @@ func (e *Enum) ToProto() proto.Message {
 	}
 }
 
+func (e *Enum) GetName() string { return e.Name }
+
 func EnumFromProto(s *schemapb.Enum) *Enum {
 	return &Enum{
 		Pos:      posFromProto(s.Pos),

backend/schema/float.go

@@ -21,3 +21,4 @@ func (*Float) schemaType()              {}
 func (*Float) schemaDecl()              {}
 func (*Float) String() string           { return "Float" }
 func (f *Float) ToProto() proto.Message { return &schemapb.Float{Pos: posToProto(f.Pos)} }
+func (*Float) GetName() string          { return "" }

backend/schema/int.go

@@ -21,3 +21,4 @@ func (*Int) schemaChildren() []Node   { return nil }
 func (*Int) schemaType()              {}
 func (*Int) String() string           { return "Int" }
 func (i *Int) ToProto() proto.Message { return &schemapb.Int{Pos: posToProto(i.Pos)} }
+func (*Int) GetName() string          { return "" }

backend/schema/metadatacalls.go

@@ -35,7 +35,7 @@ func (m *MetadataCalls) String() string {
 		w += len(str)
 		fmt.Fprint(out, str)
 	}
-	fmt.Fprintln(out)
+	fmt.Fprint(out)
 	return out.String()
 }
 

backend/schema/module.go

@@ -188,6 +188,8 @@ func (m *Module) ToProto() proto.Message {
 	}
 }
 
+func (m *Module) GetName() string { return m.Name }
+
 // ModuleFromProtoFile loads a module from the given proto-encoded file.
 func ModuleFromProtoFile(filename string) (*Module, error) {
 	data, err := os.ReadFile(filename)

backend/schema/parser.go

@@ -123,6 +123,7 @@ type Value interface {
 //sumtype:decl
 type Decl interface {
 	Node
+	GetName() string
 	schemaDecl()
 }
 

backend/schema/schema_test.go

@@ -40,7 +40,6 @@ module todo {
   verb create(todo.CreateRequest) todo.CreateResponse
       +calls todo.destroy
 
-
   verb destroy(builtin.HttpRequest<todo.DestroyRequest>) builtin.HttpResponse<todo.DestroyResponse, String>
       +ingress http GET /todo/destroy/{id}
 }

backend/schema/string.go

@@ -21,3 +21,4 @@ func (*String) schemaType()              {}
 func (*String) schemaDecl()              {}
 func (*String) String() string           { return "String" }
 func (s *String) ToProto() proto.Message { return &schemapb.String{Pos: posToProto(s.Pos)} }
+func (*String) GetName() string          { return "" }

backend/schema/time.go

@@ -21,3 +21,4 @@ func (*Time) schemaType()              {}
 func (*Time) schemaDecl()              {}
 func (*Time) String() string           { return "Time" }
 func (t *Time) ToProto() proto.Message { return &schemapb.Time{Pos: posToProto(t.Pos)} }
+func (*Time) GetName() string          { return "" }

backend/schema/typeparameter.go

@@ -21,6 +21,7 @@ func (t *TypeParameter) ToProto() protoreflect.ProtoMessage {
 }
 func (t *TypeParameter) schemaChildren() []Node { return nil }
 func (t *TypeParameter) schemaDecl()            {}
+func (t *TypeParameter) GetName() string        { return t.Name }
 
 func typeParametersToSchema(s []*schemapb.TypeParameter) []*TypeParameter {
 	var out []*TypeParameter

backend/schema/unit.go

@@ -21,3 +21,4 @@ func (u *Unit) schemaDecl()                        {}
 func (u *Unit) String() string                     { return "Unit" }
 func (u *Unit) ToProto() protoreflect.ProtoMessage { return &schemapb.Unit{Pos: posToProto(u.Pos)} }
 func (u *Unit) schemaChildren() []Node             { return nil }
+func (u *Unit) GetName() string                    { return "" }

backend/schema/validate.go

@@ -294,6 +294,16 @@ func ValidateModule(module *Module) error {
 		return next()
 	})
 	merr = cleanErrors(merr)
+	sort.SliceStable(module.Decls, func(i, j int) bool {
+		iDecl := module.Decls[i]
+		jDecl := module.Decls[j]
+		iType := reflect.TypeOf(iDecl).String()
+		jType := reflect.TypeOf(jDecl).String()
+		if iType == jType {
+			return iDecl.GetName() < jDecl.GetName()
+		}
+		return iType < jType
+	})
 	return errors.Join(merr...)
 }
 

backend/schema/verb.go

@@ -43,6 +43,9 @@ func (v *Verb) schemaChildren() []Node {
 	}
 	return children
 }
+
+func (v *Verb) GetName() string { return v.Name }
+
 func (v *Verb) String() string {
 	w := &strings.Builder{}
 	fmt.Fprint(w, encodeComments(v.Comments))

buildengine/build_go_test.go

@@ -0,0 +1,89 @@
+package buildengine
+
+import (
+	"testing"
+
+	"github.com/TBD54566975/ftl/backend/schema"
+)
+
+func TestGenerateGoModule(t *testing.T) {
+	sch := &schema.Schema{
+		Modules: []*schema.Module{
+			schema.Builtins(),
+			{Name: "other", Decls: []schema.Decl{
+				&schema.Enum{
+					Name: "Color",
+					Type: &schema.String{},
+					Variants: []*schema.EnumVariant{
+						{Name: "Red", Value: &schema.StringValue{Value: "Red"}},
+						{Name: "Blue", Value: &schema.StringValue{Value: "Blue"}},
+						{Name: "Green", Value: &schema.StringValue{Value: "Green"}},
+					},
+				},
+				&schema.Enum{
+					Name: "ColorInt",
+					Type: &schema.Int{},
+					Variants: []*schema.EnumVariant{
+						{Name: "RedInt", Value: &schema.IntValue{Value: 0}},
+						{Name: "BlueInt", Value: &schema.IntValue{Value: 1}},
+						{Name: "GreenInt", Value: &schema.IntValue{Value: 2}},
+					},
+				},
+				&schema.Data{Name: "EchoRequest"},
+				&schema.Data{Name: "EchoResponse"},
+				&schema.Verb{
+					Name:     "echo",
+					Request:  &schema.DataRef{Name: "EchoRequest"},
+					Response: &schema.DataRef{Name: "EchoResponse"},
+				},
+			}},
+			{Name: "test"},
+		},
+	}
+	expected := `// Code generated by FTL. DO NOT EDIT.
+
+//ftl:module other
+package other
+
+import (
+  "context"
+)
+
+var _ = context.Background
+
+//ftl:enum
+type Color string
+const (
+  Red Color = "Red"
+  Blue Color = "Blue"
+  Green Color = "Green"
+)
+
+//ftl:enum
+type ColorInt int
+const (
+  RedInt ColorInt = 0
+  BlueInt ColorInt = 1
+  GreenInt ColorInt = 2
+)
+
+type EchoRequest struct {
+}
+
+type EchoResponse struct {
+}
+
+//ftl:verb
+func Echo(context.Context, EchoRequest) (EchoResponse, error) {
+  panic("Verb stubs should not be called directly, instead use github.com/TBD54566975/ftl/runtime-go/ftl.Call()")
+}
+`
+	bctx := buildContext{
+		moduleDir: "testdata/modules/another",
+		buildDir:  "_ftl",
+		sch:       sch,
+	}
+	testBuild(t, bctx, []assertion{
+		assertGeneratedModule("go/modules/other/external_module.go", expected),
+	})
+}

buildengine/build_kotlin.go

@@ -158,36 +158,7 @@ var scaffoldFuncs = scaffolder.FuncMap{
 	"imports": func(m *schema.Module) []string {
 		imports := sets.NewSet[string]()
 		_ = schema.Visit(m, func(n schema.Node, next func() error) error {
-			switch n := n.(type) {
-			case *schema.DataRef:
-				decl := m.Resolve(schema.Ref{
-					Module: n.Module,
-					Name:   n.Name,
-				})
-				if decl != nil {
-					if data, ok := decl.Decl.(*schema.Data); ok {
-						if len(data.Fields) == 0 {
-							imports.Add("ftl.builtin.Empty")
-							break
-						}
-					}
-				}
-
-				if n.Module == "" {
-					break
-				}
-
-				imports.Add("ftl." + n.Module + "." + n.Name)
-
-				for _, tp := range n.TypeParameters {
-					tpRef, err := schema.ParseDataRef(tp.String())
-					if err != nil {
-						return err
-					}
-					if tpRef.Module != "" && tpRef.Module != m.Name {
-						imports.Add("ftl." + tpRef.Module + "." + tpRef.Name)
-					}
-				}
+			switch n.(type) {
 			case *schema.Verb:
 				imports.Append("xyz.block.ftl.Context", "xyz.block.ftl.Ignore", "xyz.block.ftl.Verb")
 
@@ -214,12 +185,15 @@ func genType(module *schema.Module, t schema.Type) string {
 		if decl != nil {
 			if data, ok := decl.Decl.(*schema.Data); ok {
 				if len(data.Fields) == 0 {
-					return "Empty"
+					return "ftl.builtin.Empty"
 				}
 			}
 		}
 
 		desc := t.Name
+		if t.Module != "" {
+			desc = "ftl." + t.Module + "." + desc
+		}
 		if len(t.TypeParameters) > 0 {
 			desc += "<"
 			for i, tp := range t.TypeParameters {