Add generated code marker (#12)

"// Code generated by dingo; DO NOT EDIT" is the first line of dingo.go.

Fixes #1

expression.go

@@ -28,13 +28,13 @@ func (e Expression) Dependencies() (deps []string) {
 	return pie.Strings(deps).Unique()
 }
 
-func (e Expression) performSubstitutions(services Services, fromArgs bool) string {
+func (e Expression) performSubstitutions(file *File, services Services, fromArgs bool) string {
 	stmt := string(e)
 
 	// Replace environment variables.
 	stmt = replaceAllStringSubmatchFunc(
 		regexp.MustCompile(`\${(.*?)}`), stmt, func(i []string) string {
-			astutil.AddImport(fset, file, "os")
+			astutil.AddImport(file.fset, file.file, "os")
 
 			return fmt.Sprintf("os.Getenv(\"%s\")", i[1])
 		})

file.go

@@ -1,5 +1,128 @@
 package main
 
+import (
+	"fmt"
+	"github.com/go-yaml/yaml"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"golang.org/x/tools/go/ast/astutil"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+)
+
 type File struct {
 	Services Services
+	fset     *token.FileSet
+	file     *ast.File
+}
+
+func ParseYAMLFile(filepath, outputFile string) (*File, error) {
+	f, err := ioutil.ReadFile(filepath)
+	if err != nil {
+		return nil, err
+	}
+
+	var all *File
+	err = yaml.Unmarshal(f, &all)
+	if err != nil {
+		return nil, err
+	}
+
+	all.fset = token.NewFileSet()
+	packageLine := fmt.Sprintf("// Code generated by dingo; DO NOT EDIT\npackage %s", all.getPackageName(filepath))
+	all.file, err = parser.ParseFile(all.fset, outputFile, packageLine, parser.ParseComments)
+	if err != nil {
+		return nil, err
+	}
+
+	all.file.Decls = append(all.file.Decls,
+		all.Services.astContainerStruct(),
+		all.Services.astDefaultContainer(),
+		all.astNewContainerFunc())
+
+	for _, serviceName := range all.Services.ServiceNames() {
+		definition := all.Services[serviceName]
+
+		// Add imports for type, interface and explicit imports.
+		for packageName, shortName := range definition.Imports() {
+			astutil.AddNamedImport(all.fset, all.file, shortName, packageName)
+		}
+
+		all.file.Decls = append(all.file.Decls, &ast.FuncDecl{
+			Name: newIdent("Get" + serviceName),
+			Recv: &ast.FieldList{
+				List: []*ast.Field{
+					{
+						Names: []*ast.Ident{
+							newIdent("container"),
+						},
+						Type: newIdent("*Container"),
+					},
+				},
+			},
+			Type: &ast.FuncType{
+				Params:  definition.astArguments(),
+				Results: newFieldList(definition.InterfaceOrLocalEntityType(all.Services, false)),
+			},
+			Body: definition.astFunctionBody(all, all.Services, serviceName, serviceName),
+		})
+	}
+
+	ast.SortImports(all.fset, all.file)
+
+	return all, nil
+}
+
+func (file *File) getPackageName(dingoYMLPath string) string {
+	abs, err := filepath.Abs(dingoYMLPath)
+	if err != nil {
+		panic(err)
+	}
+
+	// The directory name is not enough because it may contain a command
+	// (package main). Find the first non-test file to get the real package
+	// name.
+	dir := filepath.Dir(abs)
+	files, err := ioutil.ReadDir(dir)
+	if err != nil {
+		panic(err)
+	}
+
+	for _, fileInfo := range files {
+		if strings.HasSuffix(fileInfo.Name(), ".go") &&
+			!strings.HasSuffix(fileInfo.Name(), "_test.go") {
+			f, err := ioutil.ReadFile(dir + "/" + fileInfo.Name())
+			if err != nil {
+				panic(err)
+			}
+
+			parsedFile, err := parser.ParseFile(file.fset, fileInfo.Name(), f, 0)
+			if err != nil {
+				panic(err)
+			}
+
+			return parsedFile.Name.String()
+		}
+	}
+
+	// Couldn't find the package name. Assume command.
+	return "main"
+}
+
+func (file *File) astNewContainerFunc() *ast.FuncDecl {
+	fields := make(map[string]ast.Expr)
+
+	for _, serviceName := range file.Services.ServicesWithScope(ScopePrototype).ServiceNames() {
+		service := file.Services[serviceName]
+		fields[serviceName] = &ast.FuncLit{
+			Type: service.astFunctionPrototype(file.Services),
+			Body: service.astFunctionBody(file, file.Services, "", serviceName),
+		}
+	}
+
+	return newFunc("NewContainer", nil, []string{"*Container"}, newBlock(
+		newReturn(newCompositeLit("&Container", fields)),
+	))
 }

main.go

@@ -1,24 +1,12 @@
 package main
 
 import (
-	"fmt"
-	"github.com/go-yaml/yaml"
-	"go/ast"
-	"go/parser"
 	"go/printer"
-	"go/token"
-	"golang.org/x/tools/go/ast/astutil"
-	"io/ioutil"
 	"log"
 	"os"
-	"path/filepath"
 	"regexp"
-	"strings"
 )
 
-var fset *token.FileSet
-var file *ast.File
-
 func replaceAllStringSubmatchFunc(re *regexp.Regexp, str string, repl func([]string) string) string {
 	result := ""
 	lastIndex := 0
@@ -40,102 +28,18 @@ func main() {
 	dingoYMLPath := "dingo.yml"
 	outputFile := "dingo.go"
 
-	f, err := ioutil.ReadFile(dingoYMLPath)
-	if err != nil {
-		log.Fatalln("reading file:", err)
-	}
-
-	all := File{}
-	err = yaml.Unmarshal(f, &all)
-	if err != nil {
-		log.Fatalln("yaml:", err)
-	}
-
-	fset = token.NewFileSet()
-	packageLine := fmt.Sprintf("package %s", getPackageName(dingoYMLPath))
-	file, err = parser.ParseFile(fset, outputFile, packageLine, 0)
+	file, err := ParseYAMLFile(dingoYMLPath, outputFile)
 	if err != nil {
-		log.Fatalln("parser:", err)
+		log.Fatalln(err)
 	}
 
-	file.Decls = append(file.Decls,
-		all.Services.astContainerStruct(),
-		all.Services.astDefaultContainer(),
-		all.Services.astNewContainerFunc())
-
-	for _, serviceName := range all.Services.ServiceNames() {
-		definition := all.Services[serviceName]
-
-		// Add imports for type, interface and explicit imports.
-		for packageName, shortName := range definition.Imports() {
-			astutil.AddNamedImport(fset, file, shortName, packageName)
-		}
-
-		file.Decls = append(file.Decls, &ast.FuncDecl{
-			Name: newIdent("Get" + serviceName),
-			Recv: &ast.FieldList{
-				List: []*ast.Field{
-					{
-						Names: []*ast.Ident{
-							newIdent("container"),
-						},
-						Type: newIdent("*Container"),
-					},
-				},
-			},
-			Type: &ast.FuncType{
-				Params:  definition.astArguments(),
-				Results: newFieldList(definition.InterfaceOrLocalEntityType(all.Services, false)),
-			},
-			Body: definition.astFunctionBody(all.Services, serviceName, serviceName),
-		})
-	}
-
-	ast.SortImports(fset, file)
-
 	outFile, err := os.Create(outputFile)
 	if err != nil {
 		log.Fatalln("open file:", err)
 	}
 
-	err = printer.Fprint(outFile, fset, file)
+	err = printer.Fprint(outFile, file.fset, file.file)
 	if err != nil {
 		log.Fatalln("writer:", err)
 	}
 }
-
-func getPackageName(dingoYMLPath string) string {
-	abs, err := filepath.Abs(dingoYMLPath)
-	if err != nil {
-		panic(err)
-	}
-
-	// The directory name is not enough because it may contain a command
-	// (package main). Find the first non-test file to get the real package
-	// name.
-	dir := filepath.Dir(abs)
-	files, err := ioutil.ReadDir(dir)
-	if err != nil {
-		panic(err)
-	}
-
-	for _, fileInfo := range files {
-		if strings.HasSuffix(fileInfo.Name(), ".go") &&
-			!strings.HasSuffix(fileInfo.Name(), "_test.go") {
-			f, err := ioutil.ReadFile(dir + "/" + fileInfo.Name())
-			if err != nil {
-				panic(err)
-			}
-
-			file, err = parser.ParseFile(fset, fileInfo.Name(), f, 0)
-			if err != nil {
-				panic(err)
-			}
-
-			return file.Name.String()
-		}
-	}
-
-	// Couldn't find the package name. Assume command.
-	return "main"
-}

service.go

@@ -178,7 +178,7 @@ func (service *Service) astFunctionPrototype(services Services) *ast.FuncType {
 	}
 }
 
-func (service *Service) astFunctionBody(services Services, name, serviceName string) *ast.BlockStmt {
+func (service *Service) astFunctionBody(file *File, services Services, name, serviceName string) *ast.BlockStmt {
 	if name != "" && service.Scope == ScopePrototype {
 		var arguments []string
 		for _, dep := range service.Returns.Dependencies() {
@@ -220,7 +220,7 @@ func (service *Service) astFunctionBody(services Services, name, serviceName str
 				Tok: token.DEFINE,
 				Lhs: lhs,
 				Rhs: []ast.Expr{
-					newIdent(service.Returns.performSubstitutions(services, name == "")),
+					newIdent(service.Returns.performSubstitutions(file, services, name == "")),
 				},
 			},
 		}
@@ -244,7 +244,7 @@ func (service *Service) astFunctionBody(services Services, name, serviceName str
 		instantiation = append(instantiation, &ast.AssignStmt{
 			Tok: token.ASSIGN,
 			Lhs: []ast.Expr{&ast.Ident{Name: serviceTempVariable + "." + property.Name}},
-			Rhs: []ast.Expr{&ast.Ident{Name: property.Value.performSubstitutions(services, name == "")}},
+			Rhs: []ast.Expr{&ast.Ident{Name: property.Value.performSubstitutions(file, services, name == "")}},
 		})
 	}
 

services.go

@@ -61,22 +61,6 @@ func (services Services) astContainerStruct() *ast.GenDecl {
 	}
 }
 
-func (services Services) astNewContainerFunc() *ast.FuncDecl {
-	fields := make(map[string]ast.Expr)
-
-	for _, serviceName := range services.ServicesWithScope(ScopePrototype).ServiceNames() {
-		service := services[serviceName]
-		fields[serviceName] = &ast.FuncLit{
-			Type: service.astFunctionPrototype(services),
-			Body: service.astFunctionBody(services, "", serviceName),
-		}
-	}
-
-	return newFunc("NewContainer", nil, []string{"*Container"}, newBlock(
-		newReturn(newCompositeLit("&Container", fields)),
-	))
-}
-
 func (services Services) astDefaultContainer() *ast.GenDecl {
 	return &ast.GenDecl{
 		Tok: token.VAR,

util.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"go/ast"
+	"sort"
 )
 
 func newIdent(name string) *ast.Ident {
@@ -61,6 +62,8 @@ func newCompositeLit(ty string, m map[string]ast.Expr) *ast.CompositeLit {
 		keys = append(keys, k)
 	}
 
+	sort.Strings(keys)
+
 	for _, k := range keys {
 		exprs = append(exprs, &ast.KeyValueExpr{
 			Key:   newIdent(k),