Ignore go generate directives

CONTRIBUTING.md

@@ -11,7 +11,7 @@ feature request. Tag the issue accordingly.
 
 1. Install as usual (`go get github.com/walle/lll`)
 2. Write code and tests for your new feature
-3. Ensure everything works and the tests pass (see below)
+3. Ensure everything works, and the tests pass (see below)
 4. Consider contributing your code upstream
 
 ### Contribute upstream
@@ -23,7 +23,7 @@ feature request. Tag the issue accordingly.
 5. Write code and tests for your new feature
 6. Rebase against upstream to get changes \
 (`git fetch origin && git rebase origin/master`)
-7. Ensure everything works and the tests pass (see below)
+7. Ensure everything works, and the tests pass (see below)
 8. Commit your changes
 9. Push the branch to github (`git push fork my-new-feature`)
 10. Create a new Pull Request on GitHub

lll.go

@@ -85,6 +85,9 @@ func Process(r io.Reader, w io.Writer, path string, maxLength, tabWidth int,
 		l++
 		t := s.Text()
 		t = strings.Replace(t, "\t", spaces, -1)
+		if isGoGenerate(t) {
+			continue
+		}
 		c := utf8.RuneCountInString(t)
 		if c > maxLength {
 			if exclude != nil {

lll_test.go

@@ -10,6 +10,9 @@ import (
 	"github.com/walle/lll"
 )
 
+// Long directive example, tested by TestProcessFile
+//go:generate mockgen --build_flags=-mod=mod -destination mocks/mocks.go -package scoringmocks . IGGStorage,IEventsStorage
+
 func TestShouldSkipDirs(t *testing.T) {
 	skip, err := lll.ShouldSkip(".git", true, []string{".git"}, false, false)
 	if skip == false || err != filepath.SkipDir {
@@ -93,10 +96,13 @@ func TestProcess(t *testing.T) {
 
 func TestProcessFile(t *testing.T) {
 	b := bytes.NewBufferString("")
-	err := lll.ProcessFile(b, "lll_test.go", 80, 1, nil)
+	err := lll.ProcessFile(b, "lll_test.go", 100, 1, nil)
 	if err != nil {
 		t.Errorf("Expected %v, got %s", nil, err)
 	}
+	if b.Len() > 0 {
+		t.Errorf(`Unexpected issues in "lll_test.go": %v`, b.String())
+	}
 }
 
 func TestProcessUnicode(t *testing.T) {

utils.go

@@ -3,11 +3,13 @@ package lll
 import (
 	"bufio"
 	"bytes"
+	"strings"
 )
 
 var (
-	genHdr = []byte("// Code generated ")
-	genFtr = []byte(" DO NOT EDIT.")
+	genHdr           = []byte("// Code generated ")
+	genFtr           = []byte(" DO NOT EDIT.")
+	goGeneratePrefix = "//go:generate "
 )
 
 // isGenerated reports whether the source file is generated code
@@ -22,3 +24,9 @@ func isGenerated(src []byte) bool {
 	}
 	return false
 }
+
+// isGoGenerate reports whether the code line is "go generate" directive
+// https://github.com/golang/go/blob/master/src/cmd/go/internal/generate/generate.go#L324
+func isGoGenerate(line string) bool {
+	return strings.HasPrefix(line, goGeneratePrefix)
+}