Add support for multiple outputs

.golangci.example.yml

@@ -62,6 +62,10 @@ run:
 output:
   # colored-line-number|line-number|json|tab|checkstyle|code-climate|junit-xml|github-actions
   # default is "colored-line-number"
+  # multiple can be specified by separating them by comma, output can be provided
+  # for each of them by separating format name and path by colon symbol.
+  # Output path can be either `stdout`, `stderr` or path to the file to write to.
+  # Example "checkstyle:report.json,colored-line-number"
   format: colored-line-number
 
   # print lines of code with issue, default is true

pkg/commands/run.go

@@ -26,6 +26,8 @@ import (
 	"github.com/golangci/golangci-lint/pkg/result/processors"
 )
 
+const defaultFileMode = 0644
+
 func getDefaultIssueExcludeHelp() string {
 	parts := []string{"Use or not use default excludes:"}
 	for _, ep := range config.DefaultExcludePatterns {
@@ -400,44 +402,89 @@ func (e *Executor) runAndPrint(ctx context.Context, args []string) error {
 		return err // XXX: don't loose type
 	}
 
-	p, err := e.createPrinter()
-	if err != nil {
-		return err
+	formats := strings.Split(e.cfg.Output.Format, ",")
+	for _, format := range formats {
+		out := strings.SplitN(format, ":", 2)
+		if len(out) < 2 {
+			out = append(out, "")
+		}
+
+		err := e.printReports(ctx, issues, out[1], out[0])
+		if err != nil {
+			return err
+		}
 	}
 
 	e.setExitCodeIfIssuesFound(issues)
 
+	e.fileCache.PrintStats(e.log)
+
+	return nil
+}
+
+func (e *Executor) printReports(ctx context.Context, issues []result.Issue, path, format string) error {
+	w, shouldClose, err := e.createWriter(path)
+	if err != nil {
+		return fmt.Errorf("can't create output for %s: %w", path, err)
+	}
+
+	p, err := e.createPrinter(format, w)
+	if err != nil {
+		if file, ok := w.(io.Closer); shouldClose && ok {
+			_ = file.Close()
+		}
+		return err
+	}
+
 	if err = p.Print(ctx, issues); err != nil {
+		if file, ok := w.(io.Closer); shouldClose && ok {
+			_ = file.Close()
+		}
 		return fmt.Errorf("can't print %d issues: %s", len(issues), err)
 	}
 
-	e.fileCache.PrintStats(e.log)
+	if file, ok := w.(io.Closer); shouldClose && ok {
+		_ = file.Close()
+	}
 
 	return nil
 }
 
-func (e *Executor) createPrinter() (printers.Printer, error) {
+func (e *Executor) createWriter(path string) (io.Writer, bool, error) {
+	if path == "" || path == "stdout" {
+		return logutils.StdOut, false, nil
+	}
+	if path == "stderr" {
+		return logutils.StdErr, false, nil
+	}
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, defaultFileMode)
+	if err != nil {
+		return nil, false, err
+	}
+	return f, true, nil
+}
+
+func (e *Executor) createPrinter(format string, w io.Writer) (printers.Printer, error) {
 	var p printers.Printer
-	format := e.cfg.Output.Format
 	switch format {
 	case config.OutFormatJSON:
-		p = printers.NewJSON(&e.reportData)
+		p = printers.NewJSON(&e.reportData, w)
 	case config.OutFormatColoredLineNumber, config.OutFormatLineNumber:
 		p = printers.NewText(e.cfg.Output.PrintIssuedLine,
 			format == config.OutFormatColoredLineNumber, e.cfg.Output.PrintLinterName,
-			e.log.Child("text_printer"))
+			e.log.Child("text_printer"), w)
 	case config.OutFormatTab:
-		p = printers.NewTab(e.cfg.Output.PrintLinterName, e.log.Child("tab_printer"))
+		p = printers.NewTab(e.cfg.Output.PrintLinterName, e.log.Child("tab_printer"), w)
 	case config.OutFormatCheckstyle:
-		p = printers.NewCheckstyle()
+		p = printers.NewCheckstyle(w)
 	case config.OutFormatCodeClimate:
-		p = printers.NewCodeClimate()
+		p = printers.NewCodeClimate(w)
 	case config.OutFormatHTML:
-		p = printers.NewHTML()
+		p = printers.NewHTML(w)
 	case config.OutFormatJunitXML:
-		p = printers.NewJunitXML()
+		p = printers.NewJunitXML(w)
 	case config.OutFormatGithubActions:
-		p = printers.NewGithub()
+		p = printers.NewGithub(w)
 	default:
 		return nil, fmt.Errorf("unknown output format %s", format)
 	}

pkg/printers/checkstyle.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"encoding/xml"
 	"fmt"
+	"io"
 
 	"github.com/go-xmlfmt/xmlfmt"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
@@ -32,13 +32,15 @@ type checkstyleError struct {
 
 const defaultCheckstyleSeverity = "error"
 
-type Checkstyle struct{}
+type Checkstyle struct {
+	w io.Writer
+}
 
-func NewCheckstyle() *Checkstyle {
-	return &Checkstyle{}
+func NewCheckstyle(w io.Writer) *Checkstyle {
+	return &Checkstyle{w: w}
 }
 
-func (Checkstyle) Print(ctx context.Context, issues []result.Issue) error {
+func (p Checkstyle) Print(ctx context.Context, issues []result.Issue) error {
 	out := checkstyleOutput{
 		Version: "5.0",
 	}
@@ -82,6 +84,10 @@ func (Checkstyle) Print(ctx context.Context, issues []result.Issue) error {
 		return err
 	}
 
-	fmt.Fprintf(logutils.StdOut, "%s%s\n", xml.Header, xmlfmt.FormatXML(string(data), "", "  "))
+	_, err = fmt.Fprintf(p.w, "%s%s\n", xml.Header, xmlfmt.FormatXML(string(data), "", "  "))
+	if err != nil {
+		return err
+	}
+
 	return nil
 }

pkg/printers/codeclimate.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
@@ -24,10 +24,11 @@ type CodeClimateIssue struct {
 }
 
 type CodeClimate struct {
+	w io.Writer
 }
 
-func NewCodeClimate() *CodeClimate {
-	return &CodeClimate{}
+func NewCodeClimate(w io.Writer) *CodeClimate {
+	return &CodeClimate{w: w}
 }
 
 func (p CodeClimate) Print(ctx context.Context, issues []result.Issue) error {
@@ -52,6 +53,9 @@ func (p CodeClimate) Print(ctx context.Context, issues []result.Issue) error {
 		return err
 	}
 
-	fmt.Fprint(logutils.StdOut, string(outputJSON))
+	_, err = fmt.Fprint(p.w, string(outputJSON))
+	if err != nil {
+		return err
+	}
 	return nil
 }

pkg/printers/github.go

@@ -3,20 +3,21 @@ package printers
 import (
 	"context"
 	"fmt"
+	"io"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
 type github struct {
+	w io.Writer
 }
 
 const defaultGithubSeverity = "error"
 
 // NewGithub output format outputs issues according to GitHub actions format:
 // https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
-func NewGithub() Printer {
-	return &github{}
+func NewGithub(w io.Writer) Printer {
+	return &github{w: w}
 }
 
 // print each line as: ::error file=app.js,line=10,col=15::Something went wrong
@@ -35,9 +36,9 @@ func formatIssueAsGithub(issue *result.Issue) string {
 	return ret
 }
 
-func (g *github) Print(_ context.Context, issues []result.Issue) error {
+func (p *github) Print(_ context.Context, issues []result.Issue) error {
 	for ind := range issues {
-		_, err := fmt.Fprintln(logutils.StdOut, formatIssueAsGithub(&issues[ind]))
+		_, err := fmt.Fprintln(p.w, formatIssueAsGithub(&issues[ind]))
 		if err != nil {
 			return err
 		}

pkg/printers/html.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"fmt"
 	"html/template"
+	"io"
 	"strings"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
@@ -123,13 +123,15 @@ type htmlIssue struct {
 	Code   string
 }
 
-type HTML struct{}
+type HTML struct {
+	w io.Writer
+}
 
-func NewHTML() *HTML {
-	return &HTML{}
+func NewHTML(w io.Writer) *HTML {
+	return &HTML{w: w}
 }
 
-func (h HTML) Print(_ context.Context, issues []result.Issue) error {
+func (p HTML) Print(_ context.Context, issues []result.Issue) error {
 	var htmlIssues []htmlIssue
 
 	for i := range issues {
@@ -151,5 +153,5 @@ func (h HTML) Print(_ context.Context, issues []result.Issue) error {
 		return err
 	}
 
-	return t.Execute(logutils.StdOut, struct{ Issues []htmlIssue }{Issues: htmlIssues})
+	return t.Execute(p.w, struct{ Issues []htmlIssue }{Issues: htmlIssues})
 }

pkg/printers/json.go

@@ -3,20 +3,21 @@ package printers
 import (
 	"context"
 	"encoding/json"
-	"fmt"
+	"io"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/report"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
 type JSON struct {
 	rd *report.Data
+	w  io.Writer
 }
 
-func NewJSON(rd *report.Data) *JSON {
+func NewJSON(rd *report.Data, w io.Writer) *JSON {
 	return &JSON{
 		rd: rd,
+		w:  w,
 	}
 }
 
@@ -34,11 +35,5 @@ func (p JSON) Print(ctx context.Context, issues []result.Issue) error {
 		res.Issues = []result.Issue{}
 	}
 
-	outputJSON, err := json.Marshal(res)
-	if err != nil {
-		return err
-	}
-
-	fmt.Fprint(logutils.StdOut, string(outputJSON))
-	return nil
+	return json.NewEncoder(p.w).Encode(res)
 }

pkg/printers/junitxml.go

@@ -3,9 +3,9 @@ package printers
 import (
 	"context"
 	"encoding/xml"
+	"io"
 	"strings"
 
-	"github.com/golangci/golangci-lint/pkg/logutils"
 	"github.com/golangci/golangci-lint/pkg/result"
 )
 
@@ -35,13 +35,14 @@ type failureXML struct {
 }
 
 type JunitXML struct {
+	w io.Writer
 }
 
-func NewJunitXML() *JunitXML {
-	return &JunitXML{}
+func NewJunitXML(w io.Writer) *JunitXML {
+	return &JunitXML{w: w}
 }
 
-func (JunitXML) Print(ctx context.Context, issues []result.Issue) error {
+func (p JunitXML) Print(ctx context.Context, issues []result.Issue) error {
 	suites := make(map[string]testSuiteXML) // use a map to group by file
 
 	for ind := range issues {
@@ -70,7 +71,7 @@ func (JunitXML) Print(ctx context.Context, issues []result.Issue) error {
 		res.TestSuites = append(res.TestSuites, val)
 	}
 
-	enc := xml.NewEncoder(logutils.StdOut)
+	enc := xml.NewEncoder(p.w)
 	enc.Indent("", "  ")
 	if err := enc.Encode(res); err != nil {
 		return err

pkg/printers/tab.go

@@ -15,12 +15,14 @@ import (
 type Tab struct {
 	printLinterName bool
 	log             logutils.Log
+	w               io.Writer
 }
 
-func NewTab(printLinterName bool, log logutils.Log) *Tab {
+func NewTab(printLinterName bool, log logutils.Log, w io.Writer) *Tab {
 	return &Tab{
 		printLinterName: printLinterName,
 		log:             log,
+		w:               w,
 	}
 }
 
@@ -30,7 +32,7 @@ func (p Tab) SprintfColored(ca color.Attribute, format string, args ...interface
 }
 
 func (p *Tab) Print(ctx context.Context, issues []result.Issue) error {
-	w := tabwriter.NewWriter(logutils.StdOut, 0, 0, 2, ' ', 0)
+	w := tabwriter.NewWriter(p.w, 0, 0, 2, ' ', 0)
 
 	for i := range issues {
 		p.printIssue(&issues[i], w)

pkg/printers/text.go

@@ -3,6 +3,7 @@ package printers
 import (
 	"context"
 	"fmt"
+	"io"
 	"strings"
 
 	"github.com/fatih/color"
@@ -17,14 +18,16 @@ type Text struct {
 	printLinterName bool
 
 	log logutils.Log
+	w   io.Writer
 }
 
-func NewText(printIssuedLine, useColors, printLinterName bool, log logutils.Log) *Text {
+func NewText(printIssuedLine, useColors, printLinterName bool, log logutils.Log, w io.Writer) *Text {
 	return &Text{
 		printIssuedLine: printIssuedLine,
 		useColors:       useColors,
 		printLinterName: printLinterName,
 		log:             log,
+		w:               w,
 	}
 }
 
@@ -61,12 +64,12 @@ func (p Text) printIssue(i *result.Issue) {
 	if i.Pos.Column != 0 {
 		pos += fmt.Sprintf(":%d", i.Pos.Column)
 	}
-	fmt.Fprintf(logutils.StdOut, "%s: %s\n", pos, text)
+	fmt.Fprintf(p.w, "%s: %s\n", pos, text)
 }
 
 func (p Text) printSourceCode(i *result.Issue) {
 	for _, line := range i.SourceLines {
-		fmt.Fprintln(logutils.StdOut, line)
+		fmt.Fprintln(p.w, line)
 	}
 }
 
@@ -87,5 +90,5 @@ func (p Text) printUnderLinePointer(i *result.Issue) {
 		}
 	}
 
-	fmt.Fprintf(logutils.StdOut, "%s%s\n", string(prefixRunes), p.SprintfColored(color.FgYellow, "^"))
+	fmt.Fprintf(p.w, "%s%s\n", string(prefixRunes), p.SprintfColored(color.FgYellow, "^"))
 }

test/linters_test.go

@@ -2,8 +2,10 @@ package test
 
 import (
 	"bufio"
+	"fmt"
 	"os"
 	"os/exec"
+	"path"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -97,6 +99,64 @@ func TestGciLocal(t *testing.T) {
 		ExpectHasIssue("testdata/gci/gci.go:7: File is not `gci`-ed")
 }
 
+func TestMultipleOutputs(t *testing.T) {
+	sourcePath := filepath.Join(testdataDir, "gci", "gci.go")
+	args := []string{
+		"--disable-all", "--print-issued-lines=false", "--print-linter-name=false", "--out-format=line-number,json:stdout",
+		sourcePath,
+	}
+	rc := extractRunContextFromComments(t, sourcePath)
+	args = append(args, rc.args...)
+
+	cfg, err := yaml.Marshal(rc.config)
+	require.NoError(t, err)
+
+	testshared.NewLintRunner(t).RunWithYamlConfig(string(cfg), args...).
+		ExpectHasIssue("testdata/gci/gci.go:7: File is not `gci`-ed").
+		ExpectOutputContains(`"Issues":[`)
+}
+
+func TestStderrOutput(t *testing.T) {
+	sourcePath := filepath.Join(testdataDir, "gci", "gci.go")
+	args := []string{
+		"--disable-all", "--print-issued-lines=false", "--print-linter-name=false", "--out-format=line-number,json:stderr",
+		sourcePath,
+	}
+	rc := extractRunContextFromComments(t, sourcePath)
+	args = append(args, rc.args...)
+
+	cfg, err := yaml.Marshal(rc.config)
+	require.NoError(t, err)
+
+	testshared.NewLintRunner(t).RunWithYamlConfig(string(cfg), args...).
+		ExpectHasIssue("testdata/gci/gci.go:7: File is not `gci`-ed").
+		ExpectOutputContains(`"Issues":[`)
+}
+
+func TestFileOutput(t *testing.T) {
+	resultPath := path.Join(t.TempDir(), "golangci_lint_test_result")
+
+	sourcePath := filepath.Join(testdataDir, "gci", "gci.go")
+	args := []string{
+		"--disable-all", "--print-issued-lines=false", "--print-linter-name=false",
+		fmt.Sprintf("--out-format=json:%s,line-number", resultPath),
+		sourcePath,
+	}
+	rc := extractRunContextFromComments(t, sourcePath)
+	args = append(args, rc.args...)
+
+	cfg, err := yaml.Marshal(rc.config)
+	require.NoError(t, err)
+
+	testshared.NewLintRunner(t).RunWithYamlConfig(string(cfg), args...).
+		ExpectHasIssue("testdata/gci/gci.go:7: File is not `gci`-ed").
+		ExpectOutputNotContains(`"Issues":[`)
+
+	b, err := os.ReadFile(resultPath)
+	require.NoError(t, err)
+	require.Contains(t, string(b), `"Issues":[`)
+}
+
 func saveConfig(t *testing.T, cfg map[string]interface{}) (cfgPath string, finishFunc func()) {
 	f, err := os.CreateTemp("", "golangci_lint_test")
 	require.NoError(t, err)

test/testshared/testshared.go

@@ -76,6 +76,11 @@ func (r *RunResult) ExpectOutputContains(s string) *RunResult {
 	return r
 }
 
+func (r *RunResult) ExpectOutputNotContains(s string) *RunResult {
+	assert.NotContains(r.t, r.output, s, "exit code is %d", r.exitCode)
+	return r
+}
+
 func (r *RunResult) ExpectOutputEq(s string) *RunResult {
 	assert.Equal(r.t, s, r.output, "exit code is %d", r.exitCode)
 	return r