Merge pull request #84 from golangci/support/detect-mockgen-properly

Properly detect generated files: fix detection when

Author: jirfag

Diff for: pkg/result/processors/autogenerated_exclude.go

@@ -2,6 +2,8 @@ package processors
 
 import (
 	"fmt"
+	"go/ast"
+	"go/token"
 	"strings"
 
 	"github.com/golangci/golangci-lint/pkg/lint/astcache"
@@ -81,8 +83,32 @@ func (p *AutogeneratedExclude) getOrCreateFileSummary(i *result.Issue) (*ageFile
 		return nil, fmt.Errorf("can't parse file %s: %s", i.FilePath(), f.Err)
 	}
 
-	fs.isGenerated = isGeneratedFileByComment(f.F.Doc.Text())
+	doc := getDoc(f.F, f.Fset)
+
+	fs.isGenerated = isGeneratedFileByComment(doc)
 	return fs, nil
 }
 
+func getDoc(f *ast.File, fset *token.FileSet) string {
+	// don't use just f.Doc: e.g. mockgen leaves extra line between comment and package name
+
+	importPos := f.End()
+	if len(f.Imports) != 0 {
+		importPos = f.Imports[0].Pos()
+	}
+
+	var neededComments []string
+	for _, g := range f.Comments {
+		if g.Pos() < importPos && fset.Position(g.Pos()).Column == 1 {
+			neededComments = append(neededComments, g.Text())
+		}
+	}
+
+	if len(neededComments) == 0 {
+		return ""
+	}
+
+	return strings.Join(neededComments, "\n")
+}
+
 func (p AutogeneratedExclude) Finish() {}