Golang code templates

Useful live templates and code completion for Goland IDE.

Install settings.zip: https://www.jetbrains.com/help/go/sharing-live-templates.html#import

Golang

if err not nil return

Checks that err is not nil and writes return statement with default return values, except last - error. It would be wrapped with errors.Wrap. errors.Wrap can be easily replaced with fmt.Errorf or any other function

Abbreviation:

errr

Template text:

if $ERR$ != nil {
 return $RETURN$errors.Wrap($ERR$, "$TEXT$")$END$
}

Applicable in Go: statement

Name	Expression	Default value	Skip if defined
$ERR$	errorVariable()	"err"
$RETURN$	regularExpression(defaultReturnValues, "([^,]*$)", "")
$TEXT$	errorVariable()

errors.Wrap

Abbreviation:

wrap

Template text:

$END$ errors.Wrap($ERR$, "$TEXT$")

Applicable in Go: expression, statement

Name	Expression	Default value	Skip if defined
$ERR$	errorVariable()	"err"
$TEXT$	errorVariable()

Variadic slice declaration

Creates shortcut for in-place slice declarations. Compiler should inline function call, so this function free to use. Was created as a replacement for constructions like []string{} -> ss(), []int{} -> is(), etc.

Abbreviation:

ss

Template text:

func $NAME$$END$(slice ...$TYPE$) []$TYPE$ { return slice }

Applicable in Go: file

Name	Expression	Default value	Skip if defined
$TYPE$		"string"
$NAME$		"ss"

Json field names in camelCase

Sometimes we need to declare json fields not in snake_case format (goland used it by default), but in camelCase. This pattern also can be applied to any other tags, like sql, pg, csv.

Abbreviation:

jsonc

Template text:

json:"$FIELD_NAME$"

Applicable in Go: tag literal

Name	Expression	Default value	Skip if defined
$FIELD_NAME$	camelCase(fieldName())

Sort

Generate sort interface for your type. When go core team would add generics you may delete this.

Abbreviation:

sort

Template text:

type $SLICE$ []$TYPE$
func ($REC$ $SLICE$) Len() int           { return len($REC$) }
func ($REC$ $SLICE$) Swap(i, j int)      { $REC$[i], $REC$[j] = $REC$[j], $REC$[i] }
func ($REC$ $SLICE$) Less(i, j int) bool {
    panic("implement me")$END$
}

Applicable in Go: file

Name	Expression	Default value	Skip if defined
$TYPE$	complete()	"Some"
$SLICE$		"SomeSlice"
$REC$		"ss"

In

Checks that value is in slice of some type. In easy way.

Abbreviation:

in

Template text:

func isIn$Type$Slice(v $type$, values ...$type$) bool {
	for i := range values {
		if values[i] == v {
			return true
		}
	}
	return false
}

Applicable in Go: file

Name	Expression	Default value	Skip if defined
$type$		"string"
$Type$		"String"

Safe getter

Generates getter for struct field in protoc-gen-go style. Why do you need it? It allows access to nested fields without worrying about nil pointers.

type Value struct {
    Field1 *Struct1
}
type Struct1 struct {
    Field2 *Struct2
}
type Struct2 struct {
    UsefulString *string
}

var value *Value
var _ = value.SafeField1().SafeField2().SafeUsefulString()

func (v *Value) SafeField1() *Struct1 {
	if v == nil {
		return nil
	}
	return v.Field1
}
func (s *Struct1) SafeField2() *Struct2 {
	if s == nil {
		return nil
	}
	return s.Field2
}
func (s *Struct2) SafeUsefulString() *string {
	if s == nil {
		return nil
	}
	return s.UsefulString
}

Abbreviation:

getter

Template text:

func ($RECEIVER$ *$TYPE_1$) Safe$NAME$() $TYPE_2$ {
	if $RECEIVER$ == nil {
		return $RESULT$$END$
	}
	return $RECEIVER$.$NAME$
}