Update nolintlint to fix nolint formatting and remove unused nolint statements (#1573)

Also allow multiple ranges to satisfy a nolint statement as having been used.

pkg/golinters/nolintlint.go

@@ -72,6 +72,7 @@ func NewNoLintLint() *goanalysis.Linter {
 					Pos:                  i.Position(),
 					ExpectNoLint:         expectNoLint,
 					ExpectedNoLintLinter: expectedNolintLinter,
+					Replacement:          i.Replacement(),
 				}
 				res = append(res, goanalysis.NewIssue(issue, pass))
 			}

pkg/golinters/nolintlint/nolintlint.go

@@ -8,16 +8,21 @@ import (
 	"regexp"
 	"strings"
 	"unicode"
+
+	"github.com/golangci/golangci-lint/pkg/result"
 )
 
 type BaseIssue struct {
 	fullDirective                     string
 	directiveWithOptionalLeadingSpace string
 	position                          token.Position
+	replacement                       *result.Replacement
 }
 
-func (b BaseIssue) Position() token.Position {
+func (b BaseIssue) Position() token.Position { return b.position }
-	return b.position
+
+func (b BaseIssue) Replacement() *result.Replacement {
+	return b.replacement
 }
 
 type ExtraLeadingSpace struct {
@@ -85,7 +90,7 @@ type UnusedCandidate struct {
 func (i UnusedCandidate) Details() string {
 	details := fmt.Sprintf("directive `%s` is unused", i.fullDirective)
 	if i.ExpectedLinter != "" {
-		details += fmt.Sprintf(" for linter %s", i.ExpectedLinter)
+		details += fmt.Sprintf(" for linter %q", i.ExpectedLinter)
 	}
 	return details
 }
@@ -100,6 +105,7 @@ type Issue interface {
 	Details() string
 	Position() token.Position
 	String() string
+	Replacement() *result.Replacement
 }
 
 type Needs uint
@@ -115,7 +121,7 @@ const (
 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?$`)
+var fullDirectivePattern = regexp.MustCompile(`^//\s*nolint(?::(\s*[\w-]+\s*(?:,\s*[\w-]+\s*)*))?\s*(//.*)?\s*\n?$`)
 
 type Linter struct {
 	excludes        []string // lists individual linters that don't require explanations
@@ -164,19 +170,34 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 						directiveWithOptionalLeadingSpace = "// " + strings.TrimSpace(split[1])
 					}
 
+					pos := fset.Position(comment.Pos())
+					end := fset.Position(comment.End())
+
 					base := BaseIssue{
 						fullDirective:                     comment.Text,
 						directiveWithOptionalLeadingSpace: directiveWithOptionalLeadingSpace,
-						position:                          fset.Position(comment.Pos()),
+						position:                          pos,
 					}
 
 					// check for, report and eliminate leading spaces so we can check for other issues
-					if len(leadingSpace) > 1 {
+					if len(leadingSpace) > 0 {
-						issues = append(issues, ExtraLeadingSpace{BaseIssue: base})
+						machineReadableReplacement := &result.Replacement{
+							Inline: &result.InlineFix{
+								StartCol:  pos.Column - 1,
+								Length:    len(leadingSpace) + 2,
+								NewString: "//",
+							},
 						}
 
-					if (l.needs&NeedsMachineOnly) != 0 && len(leadingSpace) > 0 {
+						if (l.needs & NeedsMachineOnly) != 0 {
-						issues = append(issues, NotMachine{BaseIssue: base})
+							issue := NotMachine{BaseIssue: base}
+							issue.BaseIssue.replacement = machineReadableReplacement
+							issues = append(issues, issue)
+						} else if len(leadingSpace) > 1 {
+							issue := ExtraLeadingSpace{BaseIssue: base}
+							issue.BaseIssue.replacement = machineReadableReplacement
+							issues = append(issues, issue)
+						}
 					}
 
 					fullMatches := fullDirectivePattern.FindStringSubmatch(comment.Text)
@@ -188,7 +209,7 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 					lintersText, explanation := fullMatches[1], fullMatches[2]
 					var linters []string
 					if len(lintersText) > 0 {
-						lls := strings.Split(lintersText[1:], ",")
+						lls := strings.Split(lintersText, ",")
 						linters = make([]string, 0, len(lls))
 						for _, ll := range lls {
 							ll = strings.TrimSpace(ll)
@@ -206,11 +227,34 @@ func (l Linter) Run(fset *token.FileSet, nodes ...ast.Node) ([]Issue, error) {
 
 					// 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 {
-							issues = append(issues, UnusedCandidate{BaseIssue: base})
+							issue := UnusedCandidate{BaseIssue: base}
+							issue.replacement = removeNolintCompletely
+							issues = append(issues, issue)
 						} else {
-							for _, linter := range linters {
+							for i, linter := range linters {
-								issues = append(issues, UnusedCandidate{BaseIssue: base, ExpectedLinter: linter})
+								issue := UnusedCandidate{BaseIssue: base, ExpectedLinter: linter}
+								replacement := removeNolintCompletely
+								if len(linters) > 1 {
+									otherLinters := append(append([]string(nil), linters[0:i]...), linters[i+1:]...)
+									replacement = &result.Replacement{
+										Inline: &result.InlineFix{
+											StartCol:  (pos.Column - 1) + len("//") + len(leadingSpace) + len("nolint:"),
+											Length:    len(lintersText) - 1,
+											NewString: strings.Join(otherLinters, ","),
+										},
+									}
+								}
+								issue.replacement = replacement
+								issues = append(issues, issue)
 							}
 						}
 					}

pkg/golinters/nolintlint/nolintlint_test.go

@@ -7,16 +7,22 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/golangci/golangci-lint/pkg/result"
 )
 
 //nolint:funlen
 func TestNoLintLint(t *testing.T) {
+	type issueWithReplacement struct {
+		issue       string
+		replacement *result.Replacement
+	}
 	testCases := []struct {
 		desc     string
 		needs    Needs
 		excludes []string
 		contents string
-		expected []string
+		expected []issueWithReplacement
 	}{
 		{
 			desc:  "when no explanation is provided",
@@ -33,11 +39,11 @@ func foo() {
   good() //nolint // this is ok
 	other() //nolintother
 }`,
-			expected: []string{
+			expected: []issueWithReplacement{
-				"directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:5:1",
+				{"directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:5:1", nil},
-				"directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:7:9",
+				{"directive `//nolint` should provide explanation such as `//nolint // this is why` at testing.go:7:9", nil},
-				"directive `//nolint //` should provide explanation such as `//nolint // this is why` at testing.go:8:9",
+				{"directive `//nolint //` should provide explanation such as `//nolint // this is why` at testing.go:8:9", nil},
-				"directive `//nolint // ` should provide explanation such as `//nolint // this is why` at testing.go:9:9",
+				{"directive `//nolint // ` should provide explanation such as `//nolint // this is why` at testing.go:9:9", nil},
 			},
 		},
 		{
@@ -50,8 +56,8 @@ package bar
 //nolint // this is ok
 //nolint:dupl
 func foo() {}`,
-			expected: []string{
+			expected: []issueWithReplacement{
-				"directive `//nolint:dupl` should provide explanation such as `//nolint:dupl // this is why` at testing.go:6:1",
+				{"directive `//nolint:dupl` should provide explanation such as `//nolint:dupl // this is why` at testing.go:6:1", nil},
 			},
 		},
 		{
@@ -76,9 +82,9 @@ func foo() {
   bad() //nolint
   bad() // nolint // because
 }`,
-			expected: []string{
+			expected: []issueWithReplacement{
-				"directive `//nolint` should mention specific linter such as `//nolint:my-linter` at testing.go:6:9",
+				{"directive `//nolint` should mention specific linter such as `//nolint:my-linter` at testing.go:6:9", nil},
-				"directive `// nolint // because` should mention specific linter such as `// nolint:my-linter` at testing.go:7:9",
+				{"directive `// nolint // because` should mention specific linter such as `// nolint:my-linter` at testing.go:7:9", nil},
 			},
 		},
 		{
@@ -91,8 +97,17 @@ func foo() {
   bad() // nolint
   good() //nolint
 }`,
-			expected: []string{
+			expected: []issueWithReplacement{
+				{
 					"directive `// nolint` should be written without leading space as `//nolint` at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  8,
+							Length:    3,
+							NewString: "//",
+						},
+					},
+				},
 			},
 		},
 		{
@@ -104,8 +119,17 @@ func foo() {
   bad() //  nolint
   good() // nolint
 }`,
-			expected: []string{
+			expected: []issueWithReplacement{
+				{
 					"directive `//  nolint` should not have more than one leading space at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  8,
+							Length:    4,
+							NewString: "//",
+						},
+					},
+				},
 			},
 		},
 		{
@@ -119,8 +143,8 @@ func foo() {
   good() // nolint: linter1,linter2
   good() // nolint: linter1, linter2
 }`,
-			expected: []string{
+			expected: []issueWithReplacement{
-				"directive `// nolint:linter1 linter2` should match `// nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:6:9", //nolint:lll // this is a string
+				{"directive `// nolint:linter1 linter2` should match `// nolint[:<comma-separated-linters>] [// <explanation>]` at testing.go:6:9", nil}, //nolint:lll // this is a string
 			},
 		},
 		{
@@ -133,6 +157,92 @@ func foo() {
   // something else
 }`,
 		},
+		{
+			desc:  "needs unused without specific linter generates replacement",
+			needs: NeedsUnused,
+			contents: `
+package bar
+
+func foo() {
+  bad() //nolint
+}`,
+			expected: []issueWithReplacement{
+				{
+					"directive `//nolint` is unused at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  8,
+							Length:    8,
+							NewString: "",
+						},
+					},
+				},
+			},
+		},
+		{
+			desc:  "needs unused with one specific linter generates replacement",
+			needs: NeedsUnused,
+			contents: `
+package bar
+
+func foo() {
+  bad() //nolint:somelinter
+}`,
+			expected: []issueWithReplacement{
+				{
+					"directive `//nolint:somelinter` is unused for linter \"somelinter\" at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  8,
+							Length:    19,
+							NewString: "",
+						},
+					},
+				},
+			},
+		},
+		{
+			desc:  "needs unused with multiple specific linter generates replacement for each linter",
+			needs: NeedsUnused,
+			contents: `
+package bar
+
+func foo() {
+  bad() //nolint:linter1,linter2,linter3
+}`,
+			expected: []issueWithReplacement{
+				{
+					"directive `//nolint:linter1,linter2,linter3` is unused for linter \"linter1\" at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  17,
+							Length:    22,
+							NewString: "linter2,linter3",
+						},
+					},
+				},
+				{
+					"directive `//nolint:linter1,linter2,linter3` is unused for linter \"linter2\" at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  17,
+							Length:    22,
+							NewString: "linter1,linter3",
+						},
+					},
+				},
+				{
+					"directive `//nolint:linter1,linter2,linter3` is unused for linter \"linter3\" at testing.go:5:9",
+					&result.Replacement{
+						Inline: &result.InlineFix{
+							StartCol:  17,
+							Length:    22,
+							NewString: "linter1,linter2",
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for _, test := range testCases {
@@ -149,12 +259,16 @@ func foo() {
 			actualIssues, err := linter.Run(fset, expr)
 			require.NoError(t, err)
 
-			actualIssueStrs := make([]string, 0, len(actualIssues))
+			actualIssuesWithReplacements := make([]issueWithReplacement, 0, len(actualIssues))
 			for _, i := range actualIssues {
-				actualIssueStrs = append(actualIssueStrs, i.String())
+				actualIssuesWithReplacements = append(actualIssuesWithReplacements, issueWithReplacement{
+					issue:       i.String(),
+					replacement: i.Replacement(),
+				})
 			}
 
-			assert.ElementsMatch(t, test.expected, actualIssueStrs, "expected %s \nbut got %s", test.expected, actualIssues)
+			assert.ElementsMatch(t, test.expected, actualIssuesWithReplacements,
+				"expected %s \nbut got %s", test.expected, actualIssuesWithReplacements)
 		})
 	}
 }

pkg/result/issue.go

@@ -14,7 +14,7 @@ type Range struct {
 
 type Replacement struct {
 	NeedOnlyDelete bool     // need to delete all lines of the issue without replacement with new lines
-	NewLines       []string // is NeedDelete is false it's the replacement lines
+	NewLines       []string // if NeedDelete is false it's the replacement lines
 	Inline         *InlineFix
 }
 

pkg/result/processors/nolint.go

@@ -22,6 +22,7 @@ type ignoredRange struct {
 	matchedIssueFromLinter map[string]bool
 	result.Range
 	col           int
+	originalRange *ignoredRange // pre-expanded range (used to match nolintlint issues)
 }
 
 func (i *ignoredRange) doesMatch(issue *result.Issue) bool {
@@ -163,7 +164,11 @@ func (p *Nolint) shouldPassIssue(i *result.Issue) (bool, error) {
 
 	for _, ir := range fd.ignoredRanges {
 		if ir.doesMatch(i) {
+			nolintDebugf("found ignored range for issue %v: %v", i, ir)
 			ir.matchedIssueFromLinter[i.FromLinter] = true
+			if ir.originalRange != nil {
+				ir.originalRange.matchedIssueFromLinter[i.FromLinter] = true
+			}
 			return false, nil
 		}
 	}
@@ -199,9 +204,14 @@ func (e *rangeExpander) Visit(node ast.Node) ast.Visitor {
 	}
 
 	expandedRange := *foundRange
+	// store the original unexpanded range for matching nolintlint issues
+	if expandedRange.originalRange == nil {
+		expandedRange.originalRange = foundRange
+	}
 	if expandedRange.To < nodeEndLine {
 		expandedRange.To = nodeEndLine
 	}
+
 	nolintDebugf("found range is %v for node %#v [%d;%d], expanded range is %v",
 		*foundRange, node, nodeStartLine, nodeEndLine, expandedRange)
 	e.expandedRanges = append(e.expandedRanges, expandedRange)

test/testdata/fix/in/nolintlint.go

@@ -0,0 +1,13 @@
+//args: -Enolintlint -Elll
+//config: linters-settings.nolintlint.allow-leading-space=false
+package p
+
+func nolintlint() {
+	run() // nolint:bob // leading space should be dropped
+	run() //  nolint:bob // leading spaces should be dropped
+	// note that the next lines will retain trailing whitespace when fixed
+	run() //nolint // nolint should be dropped
+	run() //nolint:lll // nolint should be dropped
+	run() //nolint:alice,lll,bob // enabled linter should be dropped
+	run() //nolint:alice,lll,bob,nolintlint // enabled linter should not be dropped when nolintlint is nolinted
+}

test/testdata/fix/out/nolintlint.go

@@ -0,0 +1,13 @@
+//args: -Enolintlint -Elll
+//config: linters-settings.nolintlint.allow-leading-space=false
+package p
+
+func nolintlint() {
+	run() //nolint:bob // leading space should be dropped
+	run() //nolint:bob // leading spaces should be dropped
+	// note that the next lines will retain trailing whitespace when fixed
+	run() 
+	run() 
+	run() //nolint:alice,bob // enabled linter should be dropped
+	run() //nolint:alice,lll,bob,nolintlint // enabled linter should not be dropped when nolintlint is nolinted
+}

test/testdata/nolintlint.go

@@ -1,7 +1,7 @@
-//args: -Enolintlint
+//args: -Enolintlint -Emisspell
 //config: linters-settings.nolintlint.require-explanation=true
 //config: linters-settings.nolintlint.require-specific=true
-//config: linters-settings.nolintlint.allowing-leading-space=false
+//config: linters-settings.nolintlint.allow-leading-space=false
 package testdata
 
 import "fmt"
@@ -10,4 +10,11 @@ func Foo() {
 	fmt.Println("not specific")         //nolint // ERROR "directive `.*` should mention specific linter such as `//nolint:my-linter`"
 	fmt.Println("not machine readable") // nolint // ERROR "directive `.*`  should be written as `//nolint`"
 	fmt.Println("extra spaces")         //  nolint:deadcode // because // ERROR "directive `.*` should not have more than one leading space"
+
+	// test expanded range
+	//nolint:misspell // deliberate misspelling to trigger nolintlint
+	func() {
+		mispell := true
+		fmt.Println(mispell)
+	}()
 }