Fix #245 File header rule: index out of range [0] with length 0

.gitignore

@@ -1,3 +1,4 @@
+.idea
 golinter
 revive
 vendor

fixtures/lint-file-header6.go

@@ -0,0 +1 @@
+package fixtures // MATCH /the file doesn't have an appropriate header/

rule/file-header.go

@@ -51,25 +51,34 @@ type lintFileHeader struct {
 	onFailure func(lint.Failure)
 }
 
+var (
+	multiRegexp  = regexp.MustCompile("^/\\*")
+	singleRegexp = regexp.MustCompile("^//")
+)
+
 func (w lintFileHeader) Visit(_ ast.Node) ast.Visitor {
-	g := w.fileAst.Comments[0]
 	failure := lint.Failure{
 		Node:       w.fileAst,
 		Confidence: 1,
 		Failure:    "the file doesn't have an appropriate header",
 	}
+
+	if len(w.fileAst.Comments) == 0 {
+		w.onFailure(failure)
+		return nil
+	}
+
+	g := w.fileAst.Comments[0]
 	if g == nil {
 		w.onFailure(failure)
 		return nil
 	}
-	multi := regexp.MustCompile("^/\\*")
-	single := regexp.MustCompile("^//")
 	comment := ""
 	for _, c := range g.List {
 		text := c.Text
-		if multi.Match([]byte(text)) {
+		if multiRegexp.Match([]byte(text)) {
 			text = text[2 : len(text)-2]
-		} else if single.Match([]byte(text)) {
+		} else if singleRegexp.Match([]byte(text)) {
 			text = text[2:]
 		}
 		comment += text

test/file-header_test.go

@@ -27,4 +27,20 @@ func TestLintFileHeader(t *testing.T) {
 	testRule(t, "lint-file-header5", &rule.FileHeaderRule{}, &lint.RuleConfig{
 		Arguments: []interface{}{"^\\sfoo.*bar$"},
 	})
+
+	testRule(t, "lint-file-header6", &rule.FileHeaderRule{}, &lint.RuleConfig{
+		Arguments: []interface{}{"foobar"},
+	})
+}
+
+func BenchmarkLintFileHeader(b *testing.B) {
+	benchRule(b, "lint-file-header1", &rule.FileHeaderRule{}, &lint.RuleConfig{
+		Arguments: []interface{}{"foobar"},
+	})
+	//var t *testing.T
+	//for i := 0; i <= b.N; i++ {
+	//	testRule(t, "lint-file-header1", &rule.FileHeaderRule{}, &lint.RuleConfig{
+	//		Arguments: []interface{}{"foobar"},
+	//	})
+	//}
 }

test/import-blacklist_test.go

@@ -17,10 +17,7 @@ func TestImportsBlacklist(t *testing.T) {
 
 func BenchmarkImportsBlacklist(b *testing.B) {
 	args := []interface{}{"crypto/md5", "crypto/sha1"}
-	var t *testing.T
-	for i := 0; i <= b.N; i++ {
-		testRule(t, "imports-blacklist", &rule.ImportsBlacklistRule{}, &lint.RuleConfig{
-			Arguments: args,
-		})
-	}
+	benchRule(b, "imports-blacklist", &rule.ImportsBlacklistRule{}, &lint.RuleConfig{
+		Arguments: args,
+	})
 }

test/unused-param_test.go

@@ -11,8 +11,5 @@ func TestUnusedParam(t *testing.T) {
 }
 
 func BenchmarkUnusedParam(b *testing.B) {
-	var t *testing.T
-	for i := 0; i <= b.N; i++ {
-		testRule(t, "unused-param", &rule.UnusedParamRule{})
-	}
+	benchRule(b, "unused-param", &rule.UnusedParamRule{})
 }

test/utils.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"go/ast"
 	"go/parser"
-	"go/printer"
 	"go/token"
 	"go/types"
 	"io/ioutil"
@@ -19,14 +18,42 @@ import (
 	"github.com/pkg/errors"
 )
 
+const fixtureBasePath = "../fixtures/"
+
+func benchRule(b *testing.B, filename string, rule lint.Rule, config ...*lint.RuleConfig) {
+	fixturePath := fixtureBasePath + filename + ".go"
+	stat, err := os.Stat(fixturePath)
+	if err != nil {
+		b.Fatalf("Cannot get file info for %s: %v", rule.Name(), err)
+	}
+	c := map[string]lint.RuleConfig{}
+	if config != nil {
+		c[rule.Name()] = *config[0]
+	}
+
+	l := lint.New(func(file string) ([]byte, error) {
+		return ioutil.ReadFile(fixtureBasePath + file)
+	})
+
+	for i := 0; i < b.N; i++ {
+		ps, err := l.Lint([][]string{{stat.Name()}}, []lint.Rule{rule}, lint.Config{
+			Rules: c,
+		})
+		if err != nil {
+			b.Fatalf("Unexpected error: %s", err)
+		}
+		for range ps {
+		}
+	}
+}
+
 func testRule(t *testing.T, filename string, rule lint.Rule, config ...*lint.RuleConfig) {
-	baseDir := "../fixtures/"
-	filename = filename + ".go"
-	src, err := ioutil.ReadFile(baseDir + filename)
+	fixturePath := fixtureBasePath + filename + ".go"
+	src, err := ioutil.ReadFile(fixturePath)
 	if err != nil {
 		t.Fatalf("Bad filename path in test for %s: %v", rule.Name(), err)
 	}
-	stat, err := os.Stat(baseDir + filename)
+	stat, err := os.Stat(fixturePath)
 	if err != nil {
 		t.Fatalf("Cannot get file info for %s: %v", rule.Name(), err)
 	}
@@ -35,10 +62,16 @@ func testRule(t *testing.T, filename string, rule lint.Rule, config ...*lint.Rul
 		c[rule.Name()] = *config[0]
 	}
 	if parseInstructions(t, filename, src) == nil {
-		assertSuccess(t, baseDir, stat, []lint.Rule{rule}, c)
+		err := assertSuccess(t, fixtureBasePath, stat, []lint.Rule{rule}, c)
+		if err != nil {
+			t.Fatalf("Cannot invoke 'assertSuccess' for %s: %v", rule.Name(), err)
+		}
 		return
 	}
-	assertFailures(t, baseDir, stat, src, []lint.Rule{rule}, c)
+	err = assertFailures(t, fixtureBasePath, stat, src, []lint.Rule{rule}, c)
+	if err != nil {
+		t.Fatalf("Cannot invoke 'assertFailures' for %s: %v", rule.Name(), err)
+	}
 }
 
 func assertSuccess(t *testing.T, baseDir string, fi os.FileInfo, rules []lint.Rule, config map[string]lint.RuleConfig) error {
@@ -46,7 +79,7 @@ func assertSuccess(t *testing.T, baseDir string, fi os.FileInfo, rules []lint.Ru
 		return ioutil.ReadFile(baseDir + file)
 	})
 
-	ps, err := l.Lint([][]string{[]string{fi.Name()}}, rules, lint.Config{
+	ps, err := l.Lint([][]string{{fi.Name()}}, rules, lint.Config{
 		Rules: config,
 	})
 	if err != nil {
@@ -73,7 +106,7 @@ func assertFailures(t *testing.T, baseDir string, fi os.FileInfo, src []byte, ru
 		return errors.Errorf("Test file %v does not have instructions", fi.Name())
 	}
 
-	ps, err := l.Lint([][]string{[]string{fi.Name()}}, rules, lint.Config{
+	ps, err := l.Lint([][]string{{fi.Name()}}, rules, lint.Config{
 		Rules: config,
 	})
 	if err != nil {
@@ -200,14 +233,6 @@ func extractReplacement(line string) (string, bool) {
 	return line[a+len(start) : b], true
 }
 
-func render(fset *token.FileSet, x interface{}) string {
-	var buf bytes.Buffer
-	if err := printer.Fprint(&buf, fset, x); err != nil {
-		panic(err)
-	}
-	return buf.String()
-}
-
 func srcLine(src []byte, p token.Position) string {
 	// Run to end of line in both directions if not at line start/end.
 	lo, hi := p.Offset, p.Offset+1