implement max issues per linter limiting

internal/commands/run.go

@@ -81,6 +81,8 @@ func (e *Executor) initRun() {
 	runCmd.Flags().DurationVar(&rc.Deadline, "deadline", time.Second*30, "Deadline for total work")
 
 	runCmd.Flags().StringSliceVarP(&rc.ExcludePatterns, "exclude", "e", config.DefaultExcludePatterns, "Exclude issue by regexp")
+
+	runCmd.Flags().IntVar(&rc.MaxIssuesPerLinter, "max-issues-per-linter", 50, "Maximum issues count per one linter. Set to 0 to disable")
 }
 
 func isFullImportNeeded(linters []pkg.Linter) bool {
@@ -198,6 +200,7 @@ func (e *Executor) runAnalysis(ctx context.Context, args []string) (chan result.
 			processors.NewExclude(fmt.Sprintf("(%s)", strings.Join(e.cfg.Run.ExcludePatterns, "|"))),
 			processors.NewNolint(lintCtx.Program.Fset),
 			processors.NewUniqByLine(),
+			processors.NewMaxFromLinter(e.cfg.Run.MaxIssuesPerLinter),
 			processors.NewPathPrettifier(),
 		},
 	}

pkg/config/config.go

@@ -77,6 +77,8 @@ type Run struct {
 	ExcludePatterns []string
 
 	Deadline time.Duration
+
+	MaxIssuesPerLinter int
 }
 
 type Config struct {

pkg/result/processors/exclude.go

@@ -35,3 +35,5 @@ func (p Exclude) Process(issues []result.Issue) ([]result.Issue, error) {
 		return !p.pattern.MatchString(i.Text)
 	}), nil
 }
+
+func (p Exclude) Finish() {}

pkg/result/processors/max_from_linter.go

@@ -0,0 +1,44 @@
+package processors
+
+import (
+	"github.com/golangci/golangci-lint/pkg/result"
+	"github.com/sirupsen/logrus"
+)
+
+type MaxFromLinter struct {
+	lc    linterToCountMap
+	limit int
+}
+
+var _ Processor = &MaxFromLinter{}
+
+func NewMaxFromLinter(limit int) *MaxFromLinter {
+	return &MaxFromLinter{
+		lc:    linterToCountMap{},
+		limit: limit,
+	}
+}
+
+func (p MaxFromLinter) Name() string {
+	return "max_from_linter"
+}
+
+func (p *MaxFromLinter) Process(issues []result.Issue) ([]result.Issue, error) {
+	if p.limit <= 0 { // no limit
+		return issues, nil
+	}
+
+	return filterIssues(issues, func(i *result.Issue) bool {
+		p.lc[i.FromLinter]++ // always inc for stat
+		return p.lc[i.FromLinter] <= p.limit
+	}), nil
+}
+
+func (p MaxFromLinter) Finish() {
+	for linter, count := range p.lc {
+		if count > p.limit {
+			logrus.Infof("%d/%d issues from linter %s were hidden, use --max-issues-per-linter",
+				count-p.limit, count, linter)
+		}
+	}
+}

pkg/result/processors/max_from_linter_test.go

@@ -0,0 +1,14 @@
+package processors
+
+import (
+	"testing"
+)
+
+func TestMaxFromLinter(t *testing.T) {
+	p := NewMaxFromLinter(1)
+	gosimple := newFromLinterIssue("gosimple")
+	gofmt := newFromLinterIssue("gofmt")
+	processAssertSame(t, p, gosimple)  // ok
+	processAssertSame(t, p, gofmt)     // ok: another
+	processAssertEmpty(t, p, gosimple) // skip
+}

pkg/result/processors/max_per_file_from_linter.go

@@ -49,3 +49,5 @@ func (p *MaxPerFileFromLinter) Process(issues []result.Issue) ([]result.Issue, e
 		return true
 	}), nil
 }
+
+func (p MaxPerFileFromLinter) Finish() {}

pkg/result/processors/nolint.go

@@ -94,3 +94,5 @@ func extractFileComments(fset *token.FileSet, comments ...*ast.CommentGroup) fil
 
 	return ret
 }
+
+func (p Nolint) Finish() {}

pkg/result/processors/path_prettifier.go

@@ -44,3 +44,5 @@ func (p PathPrettifier) Process(issues []result.Issue) ([]result.Issue, error) {
 		return newI
 	}), nil
 }
+
+func (p PathPrettifier) Finish() {}

pkg/result/processors/processor.go

@@ -5,4 +5,5 @@ import "github.com/golangci/golangci-lint/pkg/result"
 type Processor interface {
 	Process(issues []result.Issue) ([]result.Issue, error)
 	Name() string
+	Finish()
 }

pkg/result/processors/uniq_by_line.go

@@ -41,3 +41,5 @@ func (p *UniqByLine) Process(issues []result.Issue) ([]result.Issue, error) {
 		return true
 	}), nil
 }
+
+func (p UniqByLine) Finish() {}

pkg/runner.go

@@ -125,6 +125,11 @@ func (r SimpleRunner) runGo(ctx context.Context, linters []Linter, lintCtx *goli
 		}
 	}
 
+	// finalize processors: logging, clearing, no heavy work here
+	for _, p := range r.Processors {
+		p.Finish()
+	}
+
 	if ctx.Err() != nil {
 		return fmt.Errorf("%d/%d linters finished: deadline exceeded: try increase it by passing --deadline option",
 			finishedN, len(linters))