Refactor nolintlint handling: Enforce directive and linter list formatting

pkg/golinters/nolintlint/nolintlint.go

@@ -7,92 +7,71 @@ import (
 	"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
+type baseIssue struct {
+	fullDirective string
+	position      token.Position
+	replacement   *result.Replacement
 }
 
-//nolint:gocritic // TODO(ldez) must be change in the future.
-func (b BaseIssue) Position() token.Position {
+func (b baseIssue) Position() token.Position {
 	return b.position
 }
 
-//nolint:gocritic // TODO(ldez) must be change in the future.
-func (b BaseIssue) Replacement() *result.Replacement {
+func (b baseIssue) Replacement() *result.Replacement {
 	return b.replacement
 }
 
 type ExtraLeadingSpace struct {
-	BaseIssue
+	baseIssue
 }
 
-//nolint:gocritic // TODO(ldez) 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)
 }
 
 func (i ExtraLeadingSpace) String() string { return toString(i) }
 
-type NotMachine struct {
-	BaseIssue
-}
-
-//nolint:gocritic // TODO(ldez) 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)
-}
-
-func (i NotMachine) String() string { return toString(i) }
-
 type NotSpecific struct {
-	BaseIssue
+	baseIssue
 }
 
-//nolint:gocritic // TODO(ldez) 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)
+	return fmt.Sprintf("directive `%s` should mention specific linter such as `//nolint:my-linter`",
+		i.fullDirective)
 }
 
 func (i NotSpecific) String() string { return toString(i) }
 
 type ParseError struct {
-	BaseIssue
+	baseIssue
 }
 
-//nolint:gocritic // TODO(ldez) 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)
+	return fmt.Sprintf("directive `%s` should match `//nolint[:<comma-separated-linters>] [// <explanation>]`",
+		i.fullDirective)
 }
 
 func (i ParseError) String() string { return toString(i) }
 
 type NoExplanation struct {
-	BaseIssue
+	baseIssue
 	fullDirectiveWithoutExplanation string
 }
 
 //nolint:gocritic // TODO(ldez) 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)
+	return fmt.Sprintf("directive `%s` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>`",
+		i.fullDirective)
 }
 
 func (i NoExplanation) String() string { return toString(i) }
 
 type UnusedCandidate struct {
-	BaseIssue
+	baseIssue
 	ExpectedLinter string
 }
 
@@ -121,17 +100,20 @@ type Issue interface {
 type Needs uint
 
 const (
+	// Deprecated: NeedsMachineOnly is deprecated as leading spaces are no longer allowed,
+	// making this condition always true. Consumers should adjust their code to assume
+	// this as the default behavior and no longer rely on NeedsMachineOnly.
 	NeedsMachineOnly Needs = 1 << iota
 	NeedsSpecific
 	NeedsExplanation
 	NeedsUnused
-	NeedsAll = NeedsMachineOnly | NeedsSpecific | NeedsExplanation
+	NeedsAll = 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?$`)
+var fullDirectivePattern = regexp.MustCompile(`^//nolint(?::([\w-]+(?:,[\w-]+)*))?(?: (//.*))?\n?$`)
 
 type Linter struct {
 	needs           Needs // indicates which linter checks to perform
@@ -146,7 +128,7 @@ func NewLinter(needs Needs, excludes []string) (*Linter, error) {
 	}
 
 	return &Linter{
-		needs:           needs | NeedsMachineOnly,
+		needs:           needs,
 		excludeByLinter: excludeByName,
 	}, nil
 }
@@ -180,47 +162,17 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 					leadingSpace = leadingSpaceMatches[1]
 				}
 
-				directiveWithOptionalLeadingSpace := "//"
-				if leadingSpace != "" {
-					directiveWithOptionalLeadingSpace += " "
-				}
-
-				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 leadingSpace != "" {
-					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)
-					}
+				base := baseIssue{
+					fullDirective: comment.Text,
+					position:      pos,
 				}
 
 				fullMatches := fullDirectivePattern.FindStringSubmatch(comment.Text)
 				if len(fullMatches) == 0 {
-					issues = append(issues, ParseError{BaseIssue: base})
+					issues = append(issues, ParseError{baseIssue: base})
 					continue
 				}
 
@@ -246,7 +198,7 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 
 				if (l.needs & NeedsSpecific) != 0 {
 					if len(linters) == 0 {
-						issues = append(issues, NotSpecific{BaseIssue: base})
+						issues = append(issues, NotSpecific{baseIssue: base})
 					}
 				}
 
@@ -261,12 +213,12 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 					}
 
 					if len(linters) == 0 {
-						issue := UnusedCandidate{BaseIssue: base}
+						issue := UnusedCandidate{baseIssue: base}
 						issue.replacement = removeNolintCompletely
 						issues = append(issues, issue)
 					} else {
 						for _, linter := range linters {
-							issue := UnusedCandidate{BaseIssue: base, ExpectedLinter: linter}
+							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
@@ -291,7 +243,7 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 					if needsExplanation {
 						fullDirectiveWithoutExplanation := trailingBlankExplanation.ReplaceAllString(comment.Text, "")
 						issues = append(issues, NoExplanation{
-							BaseIssue:                       base,
+							baseIssue:                       base,
 							fullDirectiveWithoutExplanation: fullDirectiveWithoutExplanation,
 						})
 					}

pkg/golinters/nolintlint/nolintlint_test.go

@@ -39,10 +39,10 @@ func foo() {
 	other() //nolintother
 }`,
 			expected: []issueWithReplacement{
-				{issue: "directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:5:1"},
-				{issue: "directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:7:9"},
-				{issue: "directive `//nolint //` should provide explanation such as `//nolint // this is why` at testing.go:8:9"},
-				{issue: "directive `//nolint // ` should provide explanation such as `//nolint // this is why` at testing.go:9:9"},
+				{issue: "directive `//nolint` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>` at testing.go:5:1"},
+				{issue: "directive `//nolint` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>` at testing.go:7:9"},
+				{issue: "directive `//nolint //` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>` at testing.go:8:9"},
+				{issue: "directive `//nolint // ` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>` at testing.go:9:9"},
 			},
 		},
 		{
@@ -56,7 +56,7 @@ package bar
 //nolint:dupl
 func foo() {}`,
 			expected: []issueWithReplacement{
-				{issue: "directive `//nolint:dupl` should provide explanation such as `//nolint:dupl // this is why` at testing.go:6:1"},
+				{issue: "directive `//nolint:dupl` is missing an explanation; it should follow the format `//nolint[:<comma-separated-linters>] // <explanation>` at testing.go:6:1"},
 			},
 		},
 		{
@@ -97,41 +97,29 @@ func foo() {
   good() //nolint
 }`,
 			expected: []issueWithReplacement{
-				{
-					issue: "directive `// nolint` should be written without leading space as `//nolint` at testing.go:5:9",
-					replacement: &result.Replacement{
-						Inline: &result.InlineFix{
-							StartCol:  10,
-							Length:    1,
-							NewString: "",
-						},
-					},
-				},
-				{
-					issue: "directive `//   nolint` should be written without leading space as `//nolint` at testing.go:6:9",
-					replacement: &result.Replacement{
-						Inline: &result.InlineFix{
-							StartCol:  10,
-							Length:    3,
-							NewString: "",
-						},
-					},
-				},
+				{issue: "directive `// nolint` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:5:9"},
+				{issue: "directive `//   nolint` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:6:9"},
 			},
 		},
 		{
-			desc: "spaces are allowed in comma-separated list of linters",
+			desc: "spaces are not allowed in comma-separated list of linters",
 			contents: `
 package bar
 
 func foo() {
   good() //nolint:linter1,linter-two
   bad() //nolint:linter1 linter2
-  good() //nolint: linter1,linter2
-  good() //nolint: linter1, linter2
+  bad() //nolint: linter1,linter2
+  bad() //nolint: linter1, linter2
+  bad() //nolint / description
+  bad() //nolint, // hi
 }`,
 			expected: []issueWithReplacement{
 				{issue: "directive `//nolint:linter1 linter2` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:6:9"},
+				{issue: "directive `//nolint: linter1,linter2` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:7:9"},
+				{issue: "directive `//nolint: linter1, linter2` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:8:9"},
+				{issue: "directive `//nolint / description` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:9:9"},
+				{issue: "directive `//nolint, // hi` should match `//nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:10:9"},
 			},
 		},
 		{