2021-11-11 05:56:36 +01:00

306 lines
9.0 KiB
Go

// Package nolintlint provides a linter to ensure that all //nolint directives are followed by explanations
package nolintlint
import (
"fmt"
"go/ast"
"go/token"
"regexp"
"strings"
"unicode"
"github.com/golangci/golangci-lint/pkg/result"
)
type BaseIssue struct {
fullDirective string
directiveWithOptionalLeadingSpace string
position token.Position
replacement *result.Replacement
}
//nolint:gocritic // TODO must be change in the future.
func (b BaseIssue) Position() token.Position {
return b.position
}
//nolint:gocritic // TODO must be change in the future.
func (b BaseIssue) Replacement() *result.Replacement {
return b.replacement
}
type ExtraLeadingSpace struct {
BaseIssue
}
//nolint:gocritic // TODO must be change in the future.
func (i ExtraLeadingSpace) Details() string {
return fmt.Sprintf("directive `%s` should not have more than one leading space", i.fullDirective)
}
//nolint:gocritic // TODO must be change in the future.
func (i ExtraLeadingSpace) String() string { return toString(i) }
type NotMachine struct {
BaseIssue
}
//nolint:gocritic // TODO must be change in the future.
func (i NotMachine) Details() string {
expected := i.fullDirective[:2] + strings.TrimLeftFunc(i.fullDirective[2:], unicode.IsSpace)
return fmt.Sprintf("directive `%s` should be written without leading space as `%s`",
i.fullDirective, expected)
}
//nolint:gocritic // TODO must be change in the future.
func (i NotMachine) String() string { return toString(i) }
type NotSpecific struct {
BaseIssue
}
//nolint:gocritic // TODO must be change in the future.
func (i NotSpecific) Details() string {
return fmt.Sprintf("directive `%s` should mention specific linter such as `%s:my-linter`",
i.fullDirective, i.directiveWithOptionalLeadingSpace)
}
//nolint:gocritic // TODO must be change in the future.
func (i NotSpecific) String() string { return toString(i) }
type ParseError struct {
BaseIssue
}
//nolint:gocritic // TODO must be change in the future.
func (i ParseError) Details() string {
return fmt.Sprintf("directive `%s` should match `%s[:<comma-separated-linters>] [// <explanation>]`",
i.fullDirective,
i.directiveWithOptionalLeadingSpace)
}
//nolint:gocritic // TODO must be change in the future.
func (i ParseError) String() string { return toString(i) }
type NoExplanation struct {
BaseIssue
fullDirectiveWithoutExplanation string
}
//nolint:gocritic // TODO must be change in the future.
func (i NoExplanation) Details() string {
return fmt.Sprintf("directive `%s` should provide explanation such as `%s // this is why`",
i.fullDirective, i.fullDirectiveWithoutExplanation)
}
//nolint:gocritic // TODO must be change in the future.
func (i NoExplanation) String() string { return toString(i) }
type UnusedCandidate struct {
BaseIssue
ExpectedLinter string
}
//nolint:gocritic // TODO must be change in the future.
func (i UnusedCandidate) Details() string {
details := fmt.Sprintf("directive `%s` is unused", i.fullDirective)
if i.ExpectedLinter != "" {
details += fmt.Sprintf(" for linter %q", i.ExpectedLinter)
}
return details
}
//nolint:gocritic // TODO must be change in the future.
func (i UnusedCandidate) String() string { return toString(i) }
func toString(i Issue) string {
return fmt.Sprintf("%s at %s", i.Details(), i.Position())
}
type Issue interface {
Details() string
Position() token.Position
String() string
Replacement() *result.Replacement
}
type Needs uint
const (
NeedsMachineOnly Needs = 1 << iota
NeedsSpecific
NeedsExplanation
NeedsUnused
NeedsAll = NeedsMachineOnly | NeedsSpecific | NeedsExplanation
)
var commentPattern = regexp.MustCompile(`^//\s*(nolint)(:\s*[\w-]+\s*(?:,\s*[\w-]+\s*)*)?\b`)
// matches a complete nolint directive
var fullDirectivePattern = regexp.MustCompile(`^//\s*nolint(?::(\s*[\w-]+\s*(?:,\s*[\w-]+\s*)*))?\s*(//.*)?\s*\n?$`)
type Linter struct {
needs Needs // indicates which linter checks to perform
excludeByLinter map[string]bool
}
// NewLinter creates a linter that enforces that the provided directives fulfill the provided requirements
func NewLinter(needs Needs, excludes []string) (*Linter, error) {
excludeByName := make(map[string]bool)
for _, e := range excludes {
excludeByName[e] = true
}
return &Linter{
needs: needs,
excludeByLinter: excludeByName,
}, nil
}
var leadingSpacePattern = regexp.MustCompile(`^//(\s*)`)
var trailingBlankExplanation = regexp.MustCompile(`\s*(//\s*)?$`)
//nolint:funlen,gocyclo
func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
var issues []Issue
for _, node := range nodes {
file, ok := node.(*ast.File)
if !ok {
continue
}
for _, c := range file.Comments {
for _, comment := range c.List {
if !commentPattern.MatchString(comment.Text) {
continue
}
// check for a space between the "//" and the directive
leadingSpaceMatches := leadingSpacePattern.FindStringSubmatch(comment.Text)
var leadingSpace string
if len(leadingSpaceMatches) > 0 {
leadingSpace = leadingSpaceMatches[1]
}
directiveWithOptionalLeadingSpace := comment.Text
if len(leadingSpace) > 0 {
split := strings.Split(strings.SplitN(comment.Text, ":", 2)[0], "//")
directiveWithOptionalLeadingSpace = "// " + strings.TrimSpace(split[1])
}
pos := fset.Position(comment.Pos())
end := fset.Position(comment.End())
base := BaseIssue{
fullDirective: comment.Text,
directiveWithOptionalLeadingSpace: directiveWithOptionalLeadingSpace,
position: pos,
}
// check for, report and eliminate leading spaces, so we can check for other issues
if len(leadingSpace) > 0 {
removeWhitespace := &result.Replacement{
Inline: &result.InlineFix{
StartCol: pos.Column + 1,
Length: len(leadingSpace),
NewString: "",
},
}
if (l.needs & NeedsMachineOnly) != 0 {
issue := NotMachine{BaseIssue: base}
issue.BaseIssue.replacement = removeWhitespace
issues = append(issues, issue)
} else if len(leadingSpace) > 1 {
issue := ExtraLeadingSpace{BaseIssue: base}
issue.BaseIssue.replacement = removeWhitespace
issue.BaseIssue.replacement.Inline.NewString = " " // assume a single space was intended
issues = append(issues, issue)
}
}
fullMatches := fullDirectivePattern.FindStringSubmatch(comment.Text)
if len(fullMatches) == 0 {
issues = append(issues, ParseError{BaseIssue: base})
continue
}
lintersText, explanation := fullMatches[1], fullMatches[2]
var linters []string
if len(lintersText) > 0 {
lls := strings.Split(lintersText, ",")
linters = make([]string, 0, len(lls))
rangeStart := (pos.Column - 1) + len("//") + len(leadingSpace) + len("nolint:")
for i, ll := range lls {
rangeEnd := rangeStart + len(ll)
if i < len(lls)-1 {
rangeEnd++ // include trailing comma
}
trimmedLinterName := strings.TrimSpace(ll)
if trimmedLinterName != "" {
linters = append(linters, trimmedLinterName)
}
rangeStart = rangeEnd
}
}
if (l.needs & NeedsSpecific) != 0 {
if len(linters) == 0 {
issues = append(issues, NotSpecific{BaseIssue: base})
}
}
// when detecting unused directives, we send all the directives through and filter them out in the nolint processor
if (l.needs & NeedsUnused) != 0 {
removeNolintCompletely := &result.Replacement{
Inline: &result.InlineFix{
StartCol: pos.Column - 1,
Length: end.Column - pos.Column,
NewString: "",
},
}
if len(linters) == 0 {
issue := UnusedCandidate{BaseIssue: base}
issue.replacement = removeNolintCompletely
issues = append(issues, issue)
} else {
for _, linter := range linters {
issue := UnusedCandidate{BaseIssue: base, ExpectedLinter: linter}
// only offer replacement if there is a single linter
// because of issues around commas and the possibility of all
// linters being removed
if len(linters) == 1 {
issue.replacement = removeNolintCompletely
}
issues = append(issues, issue)
}
}
}
if (l.needs&NeedsExplanation) != 0 && (explanation == "" || strings.TrimSpace(explanation) == "//") {
needsExplanation := len(linters) == 0 // if no linters are mentioned, we must have explanation
// otherwise, check if we are excluding all the mentioned linters
for _, ll := range linters {
if !l.excludeByLinter[ll] { // if a linter does require explanation
needsExplanation = true
break
}
}
if needsExplanation {
fullDirectiveWithoutExplanation := trailingBlankExplanation.ReplaceAllString(comment.Text, "")
issues = append(issues, NoExplanation{
BaseIssue: base,
fullDirectiveWithoutExplanation: fullDirectiveWithoutExplanation,
})
}
}
}
}
}
return issues, nil
}