README
¶
godefererr
An analyser that reports incorrectly returned errors from defer closures.
Errors can be returned from a defer closure by assigning the error to a
captured variable declared in the function signature. This analyser looks for
defer closures that assign captured error variables and checks that they are
correctly declared and returned.
Example
Given the following program:
package main
import (
"errors"
"log"
)
func main() {
err := returnErrorFromDefer()
if err != nil {
log.Fatal(err)
}
log.Println("test")
}
func returnErrorFromDefer() error { // return signature should be '(err error)'
var err error = nil
if err != nil {
return err
}
defer func() {
err = errors.New("defer error")
}()
return nil // return should use 'err'
}
the analyser produces the following results:
$ godefererr ./...
package_doc_example.go:17:29: return signature should use named error parameter err
package_doc_example.go:27:9: does not return 'err'
Install
$ go install gopkg.teddywing.com/defererr/cmd/godefererr@latest
License
Copyright © 2023 Teddy Wing. Licensed under the GNU GPLv3+ (see the included COPYING file).
Documentation
¶
Overview ¶
Package defererr defines an Analyzer that checks whether an error set in a defer closure is correctly returned.
Analyzer defererr ¶
defererr: report incorrectly returned errors from defer closures.
Errors can be returned from a defer closure by setting a captured error variable within the closure. In order for this to work, the error variable must be declared in the function signature, and must be returned somewhere in the function. This analyzer checks to make sure that captured error variables assigned in defer closures are correctly declared and returned.
For example:
func returnErrorFromDefer() error { // return signature should be '(err error)'
var err error = nil
if err != nil {
return err
}
defer func() {
err = errors.New("defer error")
}()
return nil // return should use 'err'
}
Index ¶
Constants ¶
This section is empty.
Variables ¶
var Analyzer = &analysis.Analyzer{
Name: "defererr",
Doc: "reports issues returning errors from defer",
Run: run,
}
Functions ¶
This section is empty.
Types ¶
This section is empty.
Source Files
Directories