initial commit

.gitignore

@@ -0,0 +1,26 @@
+.DS_Store
+
+# Idea
+.idea/
+*.iml
+
+# Binaries for programs and plugins
+/gobetter
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+.env
+.docker_build/
+bin/

README.md

@@ -0,0 +1 @@
+# gobetter

example/main.go

@@ -0,0 +1,34 @@
+package example
+
+//go:generate gobetter main.go
+
+import (
+	"go/ast"
+	"strings"
+)
+
+// DummyInterface for interface
+type DummyInterface interface{}
+
+// HelloStruct comment
+type HelloStruct struct { //+constructor
+	FirstName, LastName string  //+required
+	Age                 int     `json:"age"` //+required
+	Description         *string `json:"description"`
+	Tags                []int   `json:"tags"`
+	ZZ                  func(a1, a2 int,
+		a3 *string) interface{} //+required
+	Test  strings.Builder //+required
+	test2 *ast.Scope
+}
+
+type AnotherStruct struct { //+constructor
+	FieldAlpha string // +required
+	FieldBeta  string
+	FieldGamma HelloStruct // +required
+}
+
+func test() {
+	var z *ast.Scope = nil
+	println(z)
+}

go.mod

@@ -0,0 +1,6 @@
+module github.com/mobiletoly/gobetter
+
+go 1.16
+
+require (
+)

go.sum

@@ -0,0 +1,29 @@
+github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.4.2 h1:Gz96sIWK3OalVv/I/qNygP42zyoKp3xptRVCWRFEBvo=
+golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210616094352-59db8d763f22 h1:RqytpXGR1iVNX7psjB3ff8y7sNFinVFvkx1c8SjBkio=
+golang.org/x/sys v0.0.0-20210616094352-59db8d763f22/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.3 h1:L69ShwSZEyCsLKoAxDKeMvLDZkumEe8gXUZAjab0tX8=
+golang.org/x/tools v0.1.3/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

main.go

@@ -0,0 +1,223 @@
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+type StructParser struct {
+	fileSet            *token.FileSet
+	fileContent        []byte
+	whitespaceRegexp   *regexp.Regexp
+	flagRequiredRegexp *regexp.Regexp
+}
+
+type GobBuilder struct {
+	common          strings.Builder
+	constructorDef  strings.Builder
+	constructorBody strings.Builder
+	astFile         *ast.File
+}
+
+// HelloStruct comment
+type HelloStruct struct { //+constructor
+	// First and last names
+	FirstName string //+required
+	// Age
+	Age int `json:"age"` //+required
+	// Description
+	Description *string `json:"description"`
+	Tags        []int   `json:"tags"`
+	// Pointer to function
+	ZZ func(a1, a2 int,
+		a3 *string) interface{} //+required
+
+	Test  strings.Builder //+required
+	test2 *ast.Scope
+}
+
+func (bld *GobBuilder) appendPackage(filename string) {
+	bld.common.WriteString("// Code generated by gobetter; DO NOT EDIT.\n\n")
+	bld.common.WriteString(fmt.Sprintf("//go:generate goimports -w %s\n\n", filename))
+	bld.common.WriteString(fmt.Sprintf("package %s\n\n", bld.astFile.Name.Name))
+}
+
+func (bld *GobBuilder) appendImports() {
+	bld.common.WriteString("import (\n")
+	for _, i := range bld.astFile.Imports {
+		fmt.Println(i.Path.Value)
+		bld.common.WriteString(fmt.Sprintf("\t%s\n", i.Path.Value))
+	}
+	bld.common.WriteString(")\n\n")
+}
+
+func (bld *GobBuilder) appendArgStruct(structName string, fieldName string, fieldType string) (structArgName string) {
+	structArgName = structName + fieldName + "Arg"
+	bld.common.WriteString(fmt.Sprintf("// %s represents field %s of struct %s\n", structArgName, fieldName, structName))
+	bld.common.WriteString(fmt.Sprintf("type %s struct {\n", structArgName))
+	bld.common.WriteString(fmt.Sprintf("\tArg %s\n}\n", fieldType))
+	bld.common.WriteString(fmt.Sprintf("// %s%s creates argument for field %s\n", structName, fieldName, fieldName))
+	bld.common.WriteString(fmt.Sprintf("func %s%s(arg %s) %s {\n", structName, fieldName,
+		fieldType, structArgName))
+	bld.common.WriteString(fmt.Sprintf("\treturn %s{Arg: arg}\n}\n\n", structArgName))
+	return
+}
+
+func (bld *GobBuilder) appendArgStructConstructor(structName string, fieldName string, fieldType string) (structArgName string) {
+	structArgName = structName + fieldName + "Arg"
+	bld.common.WriteString(fmt.Sprintf("func %s%s(arg %s) %s {\n", structName, fieldName,
+		fieldType, structArgName))
+	bld.common.WriteString(fmt.Sprintf("\treturn %s{Arg: arg}\n}\n\n", structArgName))
+	return
+}
+
+func (bld *GobBuilder) appendBeginConstructorDef(structName string) {
+	bld.constructorDef.WriteString(fmt.Sprintf("// New%s creates new instance of %s struct\n", structName, structName))
+	bld.constructorDef.WriteString(fmt.Sprintf("func New%s(\n", structName))
+}
+
+func (bld *GobBuilder) appendBeginConstructorBody(structName string) {
+	bld.constructorBody.WriteString(fmt.Sprintf("\treturn %s{\n", structName))
+}
+
+func (bld *GobBuilder) appendConstructorArg(fieldName string, structArgName string) {
+	argName := "arg" + fieldName
+	bld.constructorDef.WriteString(fmt.Sprintf("\t%s %s,\n", argName, structArgName))
+	bld.constructorBody.WriteString(fmt.Sprintf("\t\t%s: %s.Arg,\n", fieldName, argName))
+}
+
+func (bld *GobBuilder) Build() string {
+	return bld.common.String()
+}
+
+func (bld *GobBuilder) AcceptStruct(structName string) {
+	if bld.constructorDef.Len() > 0 {
+		bld.common.WriteString(bld.constructorDef.String())
+		bld.common.WriteString(fmt.Sprintf(") %s {\n", structName))
+		bld.common.WriteString(bld.constructorBody.String())
+		bld.common.WriteString("\t}\n")
+		bld.common.WriteString("}\n")
+		bld.constructorDef.Reset()
+		bld.constructorBody.Reset()
+	}
+}
+
+func NewStructParser(fileSet *token.FileSet, fileContent []byte) StructParser {
+	return StructParser{
+		fileSet:            fileSet,
+		fileContent:        fileContent,
+		whitespaceRegexp:   regexp.MustCompile(`\s+`),
+		flagRequiredRegexp: regexp.MustCompile("\\b+required\\b"),
+	}
+}
+
+func (sp *StructParser) fieldTypeText(field *ast.Field) string {
+	begin := sp.fileSet.Position(field.Type.Pos()).Offset
+	end := sp.fileSet.Position(field.Type.End()).Offset
+	return sp.whitespaceRegexp.ReplaceAllString(string(sp.fileContent[begin:end]), " ")
+}
+
+func (sp *StructParser) fieldRequired(field *ast.Field) bool {
+	return sp.flagRequiredRegexp.MatchString(field.Comment.Text())
+}
+
+func fileNameWithoutExt(fileName string) string {
+	return strings.TrimSuffix(fileName, filepath.Ext(fileName))
+}
+
+func outputFilename(inFilename string) string {
+	path := filepath.Dir(inFilename)
+	ext := filepath.Ext(inFilename)
+	outFilename := fmt.Sprintf("%s/%s_gob%s", path, fileNameWithoutExt(filepath.Base(inFilename)), ext)
+	return outFilename
+}
+
+func parseCommandLineArgs() (inFilename string, outFilename string) {
+	if len(os.Args) < 2 {
+		_, _ = fmt.Fprintln(os.Stderr, "Error: filename is required")
+		os.Exit(1)
+	}
+	inFilename = os.Args[1]
+	if _, err := os.Stat(inFilename); os.IsNotExist(err) {
+		_, _ = fmt.Fprintf(os.Stderr, "File %s does not exist\n", inFilename)
+		os.Exit(1)
+	}
+
+	_, err := exec.LookPath("goimports")
+	if err != nil {
+		_, _ = fmt.Fprintln(os.Stderr, "Error: \"goimports\" executable does not exist")
+		_, _ = fmt.Fprintln(os.Stderr, "You must install it to continue with gobetter:\n"+
+			"    go get golang.org/x/tools/cmd/goimports")
+		os.Exit(1)
+	}
+
+	outFilename = outputFilename(inFilename)
+	println("Input file: " + inFilename)
+	println("Output file: " + outFilename)
+	return
+}
+
+func main() {
+
+	inFilename, outFilename := parseCommandLineArgs()
+	fileContent, err := ioutil.ReadFile(inFilename)
+	fset := token.NewFileSet()
+	astFile, err := parser.ParseFile(fset, inFilename, nil, parser.ParseComments)
+	if err != nil {
+		log.Fatal(err)
+	}
+	sp := NewStructParser(fset, fileContent)
+
+	gobBld := GobBuilder{
+		astFile: astFile,
+	}
+	gobBld.appendPackage(filepath.Base(outFilename))
+	gobBld.appendImports()
+
+	ast.Inspect(astFile, func(n ast.Node) bool {
+		ts, ok := n.(*ast.TypeSpec)
+		if !ok {
+			return true
+		}
+		st, ok := ts.Type.(*ast.StructType)
+		if !ok {
+			return true
+		}
+		fmt.Printf("Struct type declaration found : %s\n", ts.Name.Name)
+
+		structName := ts.Name.Name
+
+		for _, field := range st.Fields.List {
+			fieldTypeText := sp.fieldTypeText(field)
+			for _, fieldName := range field.Names {
+				requiredField := sp.fieldRequired(field)
+
+				if requiredField {
+					structArgName := gobBld.appendArgStruct(structName, fieldName.Name, fieldTypeText)
+					if gobBld.constructorDef.Len() == 0 {
+						gobBld.appendBeginConstructorDef(structName)
+						gobBld.appendBeginConstructorBody(structName)
+					}
+					gobBld.appendConstructorArg(fieldName.Name, structArgName)
+				}
+			}
+		}
+
+		gobBld.AcceptStruct(structName)
+		return true
+	})
+
+	result := gobBld.Build()
+	if err = ioutil.WriteFile(outFilename, []byte(result), os.FileMode(0644)); err != nil {
+		panic(err)
+	}
+}