Closes #3: Output is formatted w/gofmt by default. Added comment lines to generated files.

bootstrap/bootstrap.go

@@ -29,6 +29,7 @@ type Generator struct {
 
 	StubsOnly  bool
 	LeaveTemps bool
+	NoFormat   bool
 }
 
 // writeStub outputs an initial stubs for marshalers/unmarshalers so that the package
@@ -44,7 +45,9 @@ func (g *Generator) writeStub() error {
 		fmt.Fprintln(f, "// +build ", g.BuildTags)
 		fmt.Fprintln(f)
 	}
-
+	fmt.Fprintln(f, "// TEMPORARY AUTOGENERATED FILE: easyjson stub code to make the package")
+	fmt.Fprintln(f, "// compilable during generation.")
+	fmt.Fprintln(f)
 	fmt.Fprintln(f, "package ", g.PkgName)
 	fmt.Fprintln(f)
 	fmt.Fprintln(f, "import (")
@@ -71,7 +74,11 @@ func (g *Generator) writeMain() (path string, err error) {
 		return "", err
 	}
 
+	fmt.Fprintln(f, "// TEMPORARY AUTOGENERATED FILE: easyjson bootstapping code to launch")
+	fmt.Fprintln(f, "// the actual generator.")
+	fmt.Fprintln(f)
 	fmt.Fprintln(f, "package main")
+	fmt.Fprintln(f)
 	fmt.Fprintln(f, "import (")
 	fmt.Fprintln(f, `  "fmt"`)
 	fmt.Fprintln(f, `  "os"`)
@@ -131,6 +138,7 @@ func (g *Generator) Run() error {
 	if err != nil {
 		return err
 	}
+	defer f.Close()
 	if !g.LeaveTemps {
 		defer os.Remove(f.Name()) // will not remove after rename
 	}
@@ -142,5 +150,15 @@ func (g *Generator) Run() error {
 		return err
 	}
 
+	if !g.NoFormat {
+		cmd = exec.Command("gofmt", "-w", f.Name())
+		cmd.Stderr = os.Stderr
+		cmd.Stdout = os.Stdout
+
+		if err = cmd.Run(); err != nil {
+			return err
+		}
+	}
+
 	return os.Rename(f.Name(), g.OutName)
 }

easyjson/main.go

@@ -17,6 +17,7 @@ var omitEmpty = flag.Bool("omit_empty", false, "omit empty fields by default")
 var allStructs = flag.Bool("all", false, "generate un-/marshallers for all structs in a file")
 var leaveTemps = flag.Bool("leave_temps", false, "do not delete temporary files")
 var stubs = flag.Bool("stubs", false, "only generate stubs for marshallers/unmarshallers methods")
+var noformat = flag.Bool("noformat", false, "do not run 'gofmt -w' on output file")
 
 func generate(fname string) (err error) {
 	p := parser.Parser{AllStructs: *allStructs}
@@ -42,6 +43,7 @@ func generate(fname string) (err error) {
 		LeaveTemps:      *leaveTemps,
 		OutName:         outName,
 		StubsOnly:       *stubs,
+		NoFormat:        *noformat,
 	}
 
 	if err := g.Run(); err != nil {
@@ -54,8 +56,13 @@ func main() {
 	flag.Parse()
 
 	files := flag.Args()
-	if len(files) == 0 {
-		files = []string{os.Getenv("GOFILE")}
+
+	gofile := os.Getenv("GOFILE")
+	if len(files) == 0 && gofile != "" {
+		files = []string{gofile}
+	} else if len(files) == 0 {
+		flag.Usage()
+		os.Exit(1)
 	}
 
 	for _, fname := range files {

gen/generator.go

@@ -122,6 +122,8 @@ func (g *Generator) printHeader() {
 		fmt.Println("// +build ", g.buildTags)
 		fmt.Println()
 	}
+	fmt.Println("// AUTOGENERATED FILE: easyjson marshaller/unmarshallers.")
+	fmt.Println()
 	fmt.Println("package ", g.pkgName)
 	fmt.Println()