Merge pull request emicklei#11 from ziflex/feature/proto2gql

Added command for GraphQL Schema conversion

.gitignore

@@ -1,4 +1,8 @@
 cmd/proto2xsd/sample.proto
 cmd/proto2xsd/proto2xsd
 cmd/protofmt/protofmt
+cmd/proto2gql/proto2gql
 debug.test
+.idea/
+bin/
+.DS_Store

README.md

@@ -37,6 +37,28 @@ This repository also includes 2 commands. The `protofmt` tool is for formatting
 
 See folder `cmd/proto2xsd/README.md` for more details.
 
+### usage of proto2gql command
+
+	> proto2gql -help
+	    Usage of proto2gql [flags] [path ...]
+
+        -std_out
+            Writes transformed files to stdout
+        -txt_out string
+            Writes transformed files to .graphql file
+        -go_out string
+            Writes transformed files to .go file
+        -js_out string
+            Writes transformed files to .js file
+        -package_alias value
+            Renames packages using given aliases
+        -resolve_import value
+            Resolves given external packages
+        -no_prefix
+            Disables package prefix for type names
+
+See folder `cmd/proto2gql/README.md` for more details.
+
 ### usage of protofmt command
 
 	> protofmt -help

cmd/proto2gql/Makefile

@@ -0,0 +1,9 @@
+.PHONY: build install generate vet compile test doc fmt lint docker
+
+default: test compile
+
+compile:
+	go build -v -o ./proto2gql ./*.go
+
+test:
+	go test ./*.go

cmd/proto2gql/README.md

@@ -0,0 +1,24 @@
+# proto2gql
+
+GraphQL Schema conversion tool for Google Protocol Buffers version 3
+
+	> proto2gql -help
+	    Usage of proto2gql [flags] [path ...]
+
+        -std_out
+            Writes transformed files to stdout
+        -txt_out string
+            Writes transformed files to .graphql file
+        -go_out string
+            Writes transformed files to .go file
+        -js_out string
+            Writes transformed files to .js file
+        -package_alias value
+            Renames packages using given aliases
+        -resolve_import value
+            Resolves given external packages
+        -no_prefix
+            Disables package prefix for type names
+
+### build
+	make

cmd/proto2gql/converter.go

@@ -0,0 +1,45 @@
+package main
+
+import "strings"
+
+type Converter struct {
+	noPrefix bool
+	pkgAliases map[string]string
+}
+
+func (c *Converter) NewTypeName(scope *Scope, name string) string {
+	return scope.packageName + strings.Join(scope.path, "") + name
+}
+
+func (c *Converter) OriginalTypeName(scope *Scope, name string) string {
+	switch len(scope.path) {
+	case 0:
+		return name
+	case 1:
+		return scope.path[0] + "." + name
+	default:
+		return strings.Join(scope.path, ".") + "." + name
+	}
+}
+
+func (c *Converter) PackageName(parts []string) string {
+	var name string
+
+	if c.noPrefix == true {
+		return name
+	}
+
+	if len(c.pkgAliases) > 0 {
+		alias, exists := c.pkgAliases[strings.Join(parts, ".")]
+
+		if exists == true {
+			return alias
+		}
+	}
+
+	for _, segment := range parts {
+		name += strings.Title(segment)
+	}
+
+	return name
+}

cmd/proto2gql/file.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"os"
+	"io/ioutil"
+	"path"
+)
+
+type FileWriter struct {
+	filename string
+	file     *os.File
+	closeTag string
+	isClosed bool
+}
+
+func NewFileWriter(filename string, openTag, closeTag string) (*FileWriter, error) {
+	file, err := ioutil.TempFile(os.TempDir(), "proto2gql")
+
+	if err != nil {
+		return nil, err
+	}
+
+	file.Write([]byte(openTag))
+
+	return &FileWriter{filename, file, closeTag, false}, nil
+}
+
+func (fw *FileWriter) IsClosed() bool {
+	return fw.isClosed
+}
+
+func (fw *FileWriter) Write(p []byte) (n int, err error) {
+	return fw.file.Write(p)
+}
+
+func (fw *FileWriter) Save() error {
+	if fw.isClosed == true {
+		return nil // return an error?
+	}
+
+	tmpName := fw.file.Name()
+
+	fw.file.Write([]byte(fw.closeTag))
+
+	if err := fw.Close(); err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(path.Dir(fw.filename), os.ModePerm); err != nil {
+		return err
+	}
+
+	return os.Rename(tmpName, fw.filename)
+}
+
+func (fw *FileWriter) Remove() error {
+	if fw.isClosed == true {
+		return nil // return an error?
+	}
+
+	tmpName := fw.file.Name()
+
+	if err := fw.Close(); err != nil {
+		return err
+	}
+
+	return os.Remove(tmpName)
+}
+
+func (fw *FileWriter) Close() error {
+	if fw.isClosed == false {
+		fw.isClosed = true
+
+		return fw.file.Close()
+	}
+
+	return nil
+}