Add structs

Structs are a new feature in firemodel that provide type-safety around
Map aka Object aka Dictionary types.

Resolves #23 and #25

config.go

@@ -10,6 +10,7 @@ import (
 type Schema struct {
 	Models  []*SchemaModel
 	Enums   []*SchemaEnum
+	Structs []*SchemaStruct
 	Options SchemaOptions
 }
 
@@ -26,6 +27,12 @@ type SchemaModel struct {
 	Options     SchemaModelOptions
 }
 
+type SchemaStruct struct {
+	Name    string
+	Comment string
+	Fields  []*SchemaField
+}
+
 type SchemaOptions map[string]map[string]string
 
 func (options SchemaOptions) Get(key string) map[string]string {
@@ -125,7 +132,7 @@ type Bytes struct{}
 type Reference struct{ T *SchemaModel }
 type Array struct{ T SchemaFieldType }
 type Map struct{ T SchemaFieldType }
-type Model struct{ T *SchemaModel }
+type Struct struct{ T *SchemaStruct }
 type Enum struct{ T *SchemaEnum }
 type URL struct{}
 type File struct{}
@@ -140,13 +147,13 @@ func (t *Bytes) isSchemaTypeName()     {}
 func (t *Reference) isSchemaTypeName() {}
 func (t *Array) isSchemaTypeName()     {}
 func (t *Map) isSchemaTypeName()       {}
-func (t *Model) isSchemaTypeName()     {}
+func (t *Struct) isSchemaTypeName()    {}
 func (t *Enum) isSchemaTypeName()      {}
 func (t *URL) isSchemaTypeName()       {}
 func (t *File) isSchemaTypeName()      {}
 
 type SchemaNestedCollection struct {
 	Name    string
 	Comment string
-	Type    *Model
+	Type    *SchemaModel
 }

firemodel.example.firemodel

@@ -7,6 +7,11 @@ enum TestDirection {
     down,
 }
 
+struct TestStruct {
+  string where;
+  integer how_much;
+}
+
 // A Test is a test model.
 model TestModel {
   option firestore.path = "users/{user_id}/test_models/{test_model_id}";
@@ -27,15 +32,15 @@ model TestModel {
   geopoint location;
   array<string> colors;
   array<TestDirection> directions;
-  array<TestModel> models;
+  array<TestStruct> models;
   array<reference> refs;
   array<reference<TestTimestamps>> model_refs;
   map meta;
   map<string> meta_strs;
   TestDirection direction;
   File test_file;
   URL url;
-  TestModel nested;
+  TestStruct nested;
   collection<TestModel> nested_collection;
 }
 

internal/ast/parser.go

@@ -64,13 +64,19 @@ type ASTElement struct {
 	Model   *ASTModel  `parser:"  'model' @@"`
 	Enum    *ASTEnum   `parser:"| 'enum' @@"`
 	Option  *ASTOption `parser:"| 'option' @@"`
+	Struct  *ASTStruct `parser:"| 'struct' @@"`
 }
 
 type ASTModel struct {
 	Identifier ASTIdentifier      `parser:"@Ident"`
 	Elements   []*ASTModelElement `parser:"'{' { @@ } '}'"`
 }
 
+type ASTStruct struct {
+	Identifier ASTIdentifier       `parser:"@Ident"`
+	Elements   []*ASTStructElement `parser:"'{' { @@ } '}'"`
+}
+
 type ASTIdentifier string
 
 var (
@@ -100,6 +106,10 @@ func (id ASTIdentifier) IsReserved() bool {
 	return true
 }
 
+type ASTStructElement struct {
+	Field *ASTField `parser:"@@"`
+}
+
 type ASTModelElement struct {
 	Option *ASTOption `parser:"  'option' @@"`
 	Field  *ASTField  `parser:"| @@"`

langs/go/go.go

@@ -29,6 +29,11 @@ func (m *GoModeler) Model(schema *firemodel.Schema, sourceCoder firemodel.Source
 			return err
 		}
 	}
+	for _, structType := range schema.Structs {
+		if err := m.writeStruct(structType, sourceCoder); err != nil {
+			return err
+		}
+	}
 	for _, enum := range schema.Enums {
 		if err := m.writeEnum(enum, sourceCoder); err != nil {
 			return err
@@ -60,7 +65,10 @@ func (m *GoModeler) writeModel(model *firemodel.SchemaModel, sourceCoder firemod
 		f.Commentf("Firestore document location: /%s", fmt.Sprintf(format, commentargs...))
 	}
 
-	f.Type().Id(model.Name).StructFunc(m.fields(model))
+	f.
+		Type().
+		Id(model.Name).
+		StructFunc(m.fields(model.Name, model.Fields, model.Options.GetAutoTimestamp()))
 
 	if format, args, err := model.Options.GetFirestorePath(); format != "" {
 		f.
@@ -142,18 +150,43 @@ func (m *GoModeler) writeEnum(enum *firemodel.SchemaEnum, sourceCoder firemodel.
 	return nil
 }
 
+func (m *GoModeler) writeStruct(structType *firemodel.SchemaStruct, sourceCoder firemodel.SourceCoder) error {
+	structName := strcase.ToCamel(structType.Name)
+	f := jen.NewFile(m.packageName())
+	f.HeaderComment(fmt.Sprintf("DO NOT EDIT - Code generated by firemodel %s.", version.Version))
+
+	if structType.Comment == "" {
+		f.Commentf("TODO: Add comment to %s", structType.Name)
+	} else {
+		f.Comment(structType.Comment)
+	}
+	f.Type().Id(structName).StructFunc(m.fields(structName, structType.Fields, false))
+
+	w, err := sourceCoder.NewFile(fmt.Sprint(strcase.ToSnake(structType.Name), fileExtension))
+	if err != nil {
+		return errors.Wrap(err, "firemodel/go: open source code file")
+	}
+
+	defer w.Close()
+
+	if err := f.Render(w); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (m *GoModeler) packageName() string {
 	if m.pkg == "" {
 		return "firemodel"
 	}
 	return m.pkg
 }
 
-func (m *GoModeler) fields(model *firemodel.SchemaModel) func(g *jen.Group) {
+func (m *GoModeler) fields(structName string, fields []*firemodel.SchemaField, addTimestampFields bool) func(g *jen.Group) {
 	return func(g *jen.Group) {
-		for _, field := range model.Fields {
+		for _, field := range fields {
 			if field.Comment == "" {
-				g.Commentf("TODO: Add comment to %s.%s.", model.Name, field.Name)
+				g.Commentf("TODO: Add comment to %s.%s.", structName, field.Name)
 			} else {
 				g.Comment(field.Comment)
 			}
@@ -162,8 +195,7 @@ func (m *GoModeler) fields(model *firemodel.SchemaModel) func(g *jen.Group) {
 				Do(m.goType(field.Type)).
 				Tag(map[string]string{"firestore": strcase.ToLowerCamel(field.Name)})
 		}
-
-		if model.Options.GetAutoTimestamp() {
+		if addTimestampFields {
 			g.Line()
 			g.Comment("Creation timestamp.")
 			g.
@@ -202,7 +234,7 @@ func (m *GoModeler) goType(firetype firemodel.SchemaFieldType) func(s *jen.State
 		return func(s *jen.Statement) { s.Op("*").Qual("cloud.google.com/go/firestore", "DocumentRef") }
 	case *firemodel.GeoPoint:
 		return func(s *jen.Statement) { s.Op("*").Qual("google.golang.org/genproto/googleapis/type/latlng", "LatLng") }
-	case *firemodel.Model:
+	case *firemodel.Struct:
 		return func(s *jen.Statement) { s.Op("*").Id(firetype.T.Name) }
 	case *firemodel.Array:
 		if firetype.T != nil {