package templates
import (
"bytes"
"fmt"
"go/types"
"io/ioutil"
"os"
"path/filepath"
"reflect"
"runtime"
"sort"
"strconv"
"strings"
"text/template"
"unicode"
"github.com/99designs/gqlgen/internal/imports"
"github.com/pkg/errors"
)
// CurrentImports keeps track of all the import declarations that are needed during the execution of a plugin.
// this is done with a global because subtemplates currently get called in functions. Lets aim to remove this eventually.
var CurrentImports *Imports
// Options specify various parameters to rendering a template.
type Options struct {
// PackageName is a helper that specifies the package header declaration.
// In other words, when you write the template you don't need to specify `package X`
// at the top of the file. By providing PackageName in the Options, the Render
// function will do that for you.
PackageName string
// Template is a string of the entire template that
// will be parsed and rendered. If it's empty,
// the plugin processor will look for .gotpl files
// in the same directory of where you wrote the plugin.
Template string
// Filename is the name of the file that will be
// written to the system disk once the template is rendered.
Filename string
RegionTags bool
GeneratedHeader bool
// Data will be passed to the template execution.
Data interface{}
Funcs template.FuncMap
}
// Render renders a gql plugin template from the given Options. Render is an
// abstraction of the text/template package that makes it easier to write gqlgen
// plugins. If Options.Template is empty, the Render function will look for `.gotpl`
// files inside the directory where you wrote the plugin.
func Render(cfg Options) error {
if CurrentImports != nil {
panic(fmt.Errorf("recursive or concurrent call to RenderToFile detected"))
}
CurrentImports = &Imports{destDir: filepath.Dir(cfg.Filename)}
// load path relative to calling source file
_, callerFile, _, _ := runtime.Caller(1)
rootDir := filepath.Dir(callerFile)
funcs := Funcs()
for n, f := range cfg.Funcs {
funcs[n] = f
}
t := template.New("").Funcs(funcs)
var roots []string
if cfg.Template != "" {
var err error
t, err = t.New("template.gotpl").Parse(cfg.Template)
if err != nil {
return errors.Wrap(err, "error with provided template")
}
roots = append(roots, "template.gotpl")
} else {
// load all the templates in the directory
err := filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
name := filepath.ToSlash(strings.TrimPrefix(path, rootDir+string(os.PathSeparator)))
if !strings.HasSuffix(info.Name(), ".gotpl") {
return nil
}
b, err := ioutil.ReadFile(path)
if err != nil {
return err
}
t, err = t.New(name).Parse(string(b))
if err != nil {
return errors.Wrap(err, cfg.Filename)
}
roots = append(roots, name)
return nil
})
if err != nil {
return errors.Wrap(err, "locating templates")
}
}
// then execute all the important looking ones in order, adding them to the same file
sort.Slice(roots, func(i, j int) bool {
// important files go first
if strings.HasSuffix(roots[i], "!.gotpl") {
return true
}
if strings.HasSuffix(roots[j], "!.gotpl") {
return false
}
return roots[i] < roots[j]
})
var buf bytes.Buffer
for _, root := range roots {
if cfg.RegionTags {
buf.WriteString("\n// region " + center(70, "*", " "+root+" ") + "\n")
}
err := t.Lookup(root).Execute(&buf, cfg.Data)
if err != nil {
return errors.Wrap(err, root)
}
if cfg.RegionTags {
buf.WriteString("\n// endregion " + center(70, "*", " "+root+" ") + "\n")
}
}
var result bytes.Buffer
if cfg.GeneratedHeader {
result.WriteString("// Code generated by github.com/99designs/gqlgen, DO NOT EDIT.\n\n")
}
result.WriteString("package ")
result.WriteString(cfg.PackageName)
result.WriteString("\n\n")
result.WriteString("import (\n")
result.WriteString(CurrentImports.String())
result.WriteString(")\n")
_, err := buf.WriteTo(&result)
if err != nil {
return err
}
CurrentImports = nil
return write(cfg.Filename, result.Bytes())
}
func center(width int, pad string, s string) string {
if len(s)+2 > width {
return s
}
lpad := (width - len(s)) / 2
rpad := width - (lpad + len(s))
return strings.Repeat(pad, lpad) + s + strings.Repeat(pad, rpad)
}
func Funcs() template.FuncMap {
return template.FuncMap{
"ucFirst": ucFirst,
"lcFirst": lcFirst,
"quote": strconv.Quote,
"rawQuote": rawQuote,
"dump": Dump,
"ref": ref,
"ts": TypeIdentifier,
"call": Call,
"prefixLines": prefixLines,
"notNil": notNil,
"reserveImport": CurrentImports.Reserve,
"lookupImport": CurrentImports.Lookup,
"go": ToGo,
"goPrivate": ToGoPrivate,
"add": func(a, b int) int {
return a + b
},
"render": func(filename string, tpldata interface{}) (*bytes.Buffer, error) {
return render(resolveName(filename, 0), tpldata)
},
}
}
func ucFirst(s string) string {
if s == "" {
return ""
}
r := []rune(s)
r[0] = unicode.ToUpper(r[0])
return string(r)
}
func lcFirst(s string) string {
if s == "" {
return ""
}
r := []rune(s)
r[0] = unicode.ToLower(r[0])
return string(r)
}
func isDelimiter(c rune) bool {
return c == '-' || c == '_' || unicode.IsSpace(c)
}
func ref(p types.Type) string {
return CurrentImports.LookupType(p)
}
var pkgReplacer = strings.NewReplacer(
"/", "ᚋ",
".", "ᚗ",
"-", "ᚑ",
)
func TypeIdentifier(t types.Type) string {
res := ""
for {
switch it := t.(type) {
case *types.Pointer:
t.Underlying()
res += "ᚖ"
t = it.Elem()
case *types.Slice:
res += "ᚕ"
t = it.Elem()
case *types.Named:
res += pkgReplacer.Replace(it.Obj().Pkg().Path())
res += "ᚐ"
res += it.Obj().Name()
return res
case *types.Basic:
res += it.Name()
return res
case *types.Map:
res += "map"
return res
case *types.Interface:
res += "interface"
return res
default:
panic(fmt.Errorf("unexpected type %T", it))
}
}
}
func Call(p *types.Func) string {
pkg := CurrentImports.Lookup(p.Pkg().Path())
if pkg != "" {
pkg += "."
}
if p.Type() != nil {
// make sure the returned type is listed in our imports.
ref(p.Type().(*types.Signature).Results().At(0).Type())
}
return pkg + p.Name()
}
func ToGo(name string) string {
runes := make([]rune, 0, len(name))
wordWalker(name, func(info *wordInfo) {
word := info.Word
if info.MatchCommonInitial {
word = strings.ToUpper(word)
} else if !info.HasCommonInitial {
if strings.ToUpper(word) == word || strings.ToLower(word) == word {
// FOO or foo → Foo
// FOo → FOo
word = ucFirst(strings.ToLower(word))
}
}
runes = append(runes, []rune(word)...)
})
return string(runes)
}
func ToGoPrivate(name string) string {
runes := make([]rune, 0, len(name))
first := true
wordWalker(name, func(info *wordInfo) {
word := info.Word
if first {
if strings.ToUpper(word) == word || strings.ToLower(word) == word {
// ID → id, CAMEL → camel
word = strings.ToLower(info.Word)
} else {
// ITicket → iTicket
word = lcFirst(info.Word)
}
first = false
} else if info.MatchCommonInitial {
word = strings.ToUpper(word)
} else if !info.HasCommonInitial {
word = ucFirst(strings.ToLower(word))
}
runes = append(runes, []rune(word)...)
})
return sanitizeKeywords(string(runes))
}
type wordInfo struct {
Word string
MatchCommonInitial bool
HasCommonInitial bool
}
// This function is based on the following code.
// https://github.com/golang/lint/blob/06c8688daad7faa9da5a0c2f163a3d14aac986ca/lint.go#L679
func wordWalker(str string, f func(*wordInfo)) {
runes := []rune(str)
w, i := 0, 0 // index of start of word, scan
hasCommonInitial := false
for i+1 <= len(runes) {
eow := false // whether we hit the end of a word
if i+1 == len(runes) {
eow = true
} else if isDelimiter(runes[i+1]) {
// underscore; shift the remainder forward over any run of underscores
eow = true
n := 1
for i+n+1 < len(runes) && isDelimiter(runes[i+n+1]) {
n++
}
// Leave at most one underscore if the underscore is between two digits
if i+n+1 < len(runes) && unicode.IsDigit(runes[i]) && unicode.IsDigit(runes[i+n+1]) {
n--
}
copy(runes[i+1:], runes[i+n+1:])
runes = runes[:len(runes)-n]
} else if unicode.IsLower(runes[i]) && !unicode.IsLower(runes[i+1]) {
// lower->non-lower
eow = true
}
i++
// [w,i) is a word.
word := string(runes[w:i])
if !eow && commonInitialisms[word] && !unicode.IsLower(runes[i]) {
// through
// split IDFoo → ID, Foo
// but URLs → URLs
} else if !eow {
if commonInitialisms[word] {
hasCommonInitial = true
}
continue
}
matchCommonInitial := false
if commonInitialisms[strings.ToUpper(word)] {
hasCommonInitial = true
matchCommonInitial = true
}
f(&wordInfo{
Word: word,
MatchCommonInitial: matchCommonInitial,
HasCommonInitial: hasCommonInitial,
})
hasCommonInitial = false
w = i
}
}
var keywords = []string{
"break",
"default",
"func",
"interface",
"select",
"case",
"defer",
"go",
"map",
"struct",
"chan",
"else",
"goto",
"package",
"switch",
"const",
"fallthrough",
"if",
"range",
"type",
"continue",
"for",
"import",
"return",
"var",
"_",
}
// sanitizeKeywords prevents collisions with go keywords for arguments to resolver functions
func sanitizeKeywords(name string) string {
for _, k := range keywords {
if name == k {
return name + "Arg"
}
}
return name
}
// commonInitialisms is a set of common initialisms.
// Only add entries that are highly unlikely to be non-initialisms.
// For instance, "ID" is fine (Freudian code is rare), but "AND" is not.
var commonInitialisms = map[string]bool{
"ACL": true,
"API": true,
"ASCII": true,
"CPU": true,
"CSS": true,
"DNS": true,
"EOF": true,
"GUID": true,
"HTML": true,
"HTTP": true,
"HTTPS": true,
"ID": true,
"IP": true,
"JSON": true,
"LHS": true,
"QPS": true,
"RAM": true,
"RHS": true,
"RPC": true,
"SLA": true,
"SMTP": true,
"SQL": true,
"SSH": true,
"TCP": true,
"TLS": true,
"TTL": true,
"UDP": true,
"UI": true,
"UID": true,
"UUID": true,
"URI": true,
"URL": true,
"UTF8": true,
"VM": true,
"XML": true,
"XMPP": true,
"XSRF": true,
"XSS": true,
}
func rawQuote(s string) string {
return "`" + strings.Replace(s, "`", "`+\"`\"+`", -1) + "`"
}
func notNil(field string, data interface{}) bool {
v := reflect.ValueOf(data)
if v.Kind() == reflect.Ptr {
v = v.Elem()
}
if v.Kind() != reflect.Struct {
return false
}
val := v.FieldByName(field)
return val.IsValid() && !val.IsNil()
}
func Dump(val interface{}) string {
switch val := val.(type) {
case int:
return strconv.Itoa(val)
case int64:
return fmt.Sprintf("%d", val)
case float64:
return fmt.Sprintf("%f", val)
case string:
return strconv.Quote(val)
case bool:
return strconv.FormatBool(val)
case nil:
return "nil"
case []interface{}:
var parts []string
for _, part := range val {
parts = append(parts, Dump(part))
}
return "[]interface{}{" + strings.Join(parts, ",") + "}"
case map[string]interface{}:
buf := bytes.Buffer{}
buf.WriteString("map[string]interface{}{")
var keys []string
for key := range val {
keys = append(keys, key)
}
sort.Strings(keys)
for _, key := range keys {
data := val[key]
buf.WriteString(strconv.Quote(key))
buf.WriteString(":")
buf.WriteString(Dump(data))
buf.WriteString(",")
}
buf.WriteString("}")
return buf.String()
default:
panic(fmt.Errorf("unsupported type %T", val))
}
}
func prefixLines(prefix, s string) string {
return prefix + strings.Replace(s, "\n", "\n"+prefix, -1)
}
func resolveName(name string, skip int) string {
if name[0] == '.' {
// load path relative to calling source file
_, callerFile, _, _ := runtime.Caller(skip + 1)
return filepath.Join(filepath.Dir(callerFile), name[1:])
}
// load path relative to this directory
_, callerFile, _, _ := runtime.Caller(0)
return filepath.Join(filepath.Dir(callerFile), name)
}
func render(filename string, tpldata interface{}) (*bytes.Buffer, error) {
t := template.New("").Funcs(Funcs())
b, err := ioutil.ReadFile(filename)
if err != nil {
return nil, err
}
t, err = t.New(filepath.Base(filename)).Parse(string(b))
if err != nil {
panic(err)
}
buf := &bytes.Buffer{}
return buf, t.Execute(buf, tpldata)
}
func write(filename string, b []byte) error {
err := os.MkdirAll(filepath.Dir(filename), 0755)
if err != nil {
return errors.Wrap(err, "failed to create directory")
}
formatted, err := imports.Prune(filename, b)
if err != nil {
fmt.Fprintf(os.Stderr, "gofmt failed on %s: %s\n", filepath.Base(filename), err.Error())
formatted = b
}
err = ioutil.WriteFile(filename, formatted, 0644)
if err != nil {
return errors.Wrapf(err, "failed to write %s", filename)
}
return nil
}
