Add errname linter (golangci#2129)

* Add errname linter

* bump errname version

go.mod

@@ -4,6 +4,7 @@ go 1.15
 
 require (
 	4d63.com/gochecknoglobals v0.0.0-20201008074935-acfc0b28355a
+	github.com/Antonboom/errname v0.1.3
 	github.com/BurntSushi/toml v0.3.1
 	github.com/Djarvur/go-err113 v0.0.0-20210108212216-aea10b59be24
 	github.com/OpenPeeDeeP/depguard v1.0.1

pkg/golinters/errname.go

@@ -0,0 +1,21 @@
+package golinters
+
+import (
+	"github.com/Antonboom/errname/pkg/analyzer"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewErrName() *goanalysis.Linter {
+	analyzers := []*analysis.Analyzer{
+		analyzer.New(),
+	}
+
+	return goanalysis.NewLinter(
+		"errname",
+		"Checks that sentinel errors are prefixed with the `Err` and error types are suffixed with the `Error`.",
+		analyzers,
+		nil,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/lint/lintersdb/manager.go

@@ -501,6 +501,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithSince("v1.40.0").
 			WithPresets(linter.PresetStyle).
 			WithURL("https://github.com/ldez/tagliatelle"),
+		linter.NewConfig(golinters.NewErrName()).
+			WithPresets(linter.PresetStyle).
+			WithLoadForGoAnalysis().
+			WithURL("https://github.com/Antonboom/errname").
+			WithSince("v1.42.0"),
 
 		linter.NewConfig(golinters.NewCheckBannedFunc()).
 			WithPresets(linter.PresetStyle),

test/testdata/errname.go

@@ -0,0 +1,55 @@
+//args: -Eerrname
+package testdata
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	EOF          = errors.New("end of file")
+	ErrEndOfFile = errors.New("end of file")
+	errEndOfFile = errors.New("end of file")
+
+	EndOfFileError = errors.New("end of file") // ERROR "the variable name `EndOfFileError` should conform to the `ErrXxx` format"
+	ErrorEndOfFile = errors.New("end of file") // ERROR "the variable name `ErrorEndOfFile` should conform to the `ErrXxx` format"
+	EndOfFileErr   = errors.New("end of file") // ERROR "the variable name `EndOfFileErr` should conform to the `ErrXxx` format"
+	endOfFileError = errors.New("end of file") // ERROR "the variable name `endOfFileError` should conform to the `errXxx` format"
+	errorEndOfFile = errors.New("end of file") // ERROR "the variable name `errorEndOfFile` should conform to the `errXxx` format"
+)
+
+const maxSize = 256
+
+var (
+	ErrOutOfSize = fmt.Errorf("out of size (max %d)", maxSize)
+	errOutOfSize = fmt.Errorf("out of size (max %d)", maxSize)
+
+	OutOfSizeError = fmt.Errorf("out of size (max %d)", maxSize) // ERROR "the variable name `OutOfSizeError` should conform to the `ErrXxx` format"
+	outOfSizeError = fmt.Errorf("out of size (max %d)", maxSize) // ERROR "the variable name `outOfSizeError` should conform to the `errXxx` format"
+)
+
+func errInsideFuncIsNotSentinel() error {
+	var lastErr error
+	return lastErr
+}
+
+type NotErrorType struct{}
+
+func (t NotErrorType) Set() {}
+func (t NotErrorType) Get() {}
+
+type DNSConfigError struct{}
+
+func (D DNSConfigError) Error() string { return "DNS config error" }
+
+type someTypeWithoutPtr struct{}           // ERROR "the type name `someTypeWithoutPtr` should conform to the `xxxError` format"
+func (s someTypeWithoutPtr) Error() string { return "someTypeWithoutPtr" }
+
+type SomeTypeWithoutPtr struct{}           // ERROR "the type name `SomeTypeWithoutPtr` should conform to the `XxxError` format"
+func (s SomeTypeWithoutPtr) Error() string { return "SomeTypeWithoutPtr" }
+
+type someTypeWithPtr struct{}            // ERROR "the type name `someTypeWithPtr` should conform to the `xxxError` format"
+func (s *someTypeWithPtr) Error() string { return "someTypeWithPtr" }
+
+type SomeTypeWithPtr struct{}            // ERROR "the type name `SomeTypeWithPtr` should conform to the `XxxError` format"
+func (s *SomeTypeWithPtr) Error() string { return "SomeTypeWithPtr" }