Hide standard-json format for now

Similar to debug, keep this format out of help text, since in most cases
it would be better to product the desired format directly in gotestsum.

Also change to the new closure style of formatter that allows writing
bytes directly without converting to string.

cmd/main.go

@@ -136,7 +136,6 @@ Formats:
     pkgname                  print a line for each package
     pkgname-and-test-fails   print a line for each package and failed test output
     testname                 print a line for each test and package
-    standard-json            standard go test -json format
     standard-quiet           standard go test format
     standard-verbose         standard go test -v format
 

cmd/testdata/gotestsum-help-text

@@ -35,7 +35,6 @@ Formats:
     pkgname                  print a line for each package
     pkgname-and-test-fails   print a line for each package and failed test output
     testname                 print a line for each test and package
-    standard-json            standard go test -json format
     standard-quiet           standard go test format
     standard-verbose         standard go test -v format
 

testjson/format.go

@@ -1,7 +1,7 @@
 package testjson
 
 import (
-	"encoding/json"
+	"bufio"
 	"fmt"
 	"io"
 	"strings"
@@ -43,12 +43,14 @@ func standardQuietFormat(event TestEvent, _ *Execution) string {
 }
 
 // go test -json
-func standardJSONFormat(event TestEvent, _ *Execution) string {
-	b, err := json.Marshal(event)
-	if err != nil {
-		return ""
-	}
-	return string(b) + "\n"
+func standardJSONFormat(out io.Writer) EventFormatter {
+	buf := bufio.NewWriter(out)
+	// nolint:errcheck // errors are returned by Flush
+	return eventFormatterFunc(func(event TestEvent, _ *Execution) error {
+		buf.Write(event.raw)
+		buf.WriteRune('\n')
+		return buf.Flush()
+	})
 }
 
 func testNameFormat(event TestEvent, exec *Execution) string {
@@ -240,6 +242,12 @@ type EventFormatter interface {
 	Format(event TestEvent, output *Execution) error
 }
 
+type eventFormatterFunc func(event TestEvent, output *Execution) error
+
+func (e eventFormatterFunc) Format(event TestEvent, output *Execution) error {
+	return e(event, output)
+}
+
 type FormatOptions struct {
 	HideEmptyPackages    bool
 	UseHiVisibilityIcons bool
@@ -251,7 +259,7 @@ func NewEventFormatter(out io.Writer, format string, formatOpts FormatOptions) E
 	case "debug":
 		return &formatAdapter{out, debugFormat}
 	case "standard-json":
-		return &formatAdapter{out, standardJSONFormat}
+		return standardJSONFormat(out)
 	case "standard-verbose":
 		return &formatAdapter{out, standardVerboseFormat}
 	case "standard-quiet":

testjson/format_test.go

@@ -2,6 +2,7 @@ package testjson
 
 import (
 	"bytes"
+	"io"
 	"testing"
 
 	"gotest.tools/v3/assert"
@@ -55,7 +56,6 @@ func newFakeHandler(formatter EventFormatter, inputName string) *fakeHandler {
 	return &fakeHandler{
 		inputName: inputName,
 		formatter: formatter,
-		out:       new(bytes.Buffer),
 		err:       new(bytes.Buffer),
 	}
 }
@@ -77,20 +77,27 @@ func patchPkgPathPrefix(t *testing.T, val string) {
 	})
 }
 
+func withAdapter(format func(TestEvent, *Execution) string) func(io.Writer) EventFormatter {
+	return func(out io.Writer) EventFormatter {
+		return &formatAdapter{out: out, format: format}
+	}
+}
+
 func TestFormats_DefaultGoTestJson(t *testing.T) {
 	type testCase struct {
 		name        string
-		format      func(event TestEvent, exec *Execution) string
+		format      func(io.Writer) EventFormatter
 		expectedOut string
 		expected    func(t *testing.T, exec *Execution)
 	}
 
 	run := func(t *testing.T, tc testCase) {
-		shim := newFakeHandlerWithAdapter(tc.format, "input/go-test-json")
+		out := new(bytes.Buffer)
+		shim := newFakeHandler(tc.format(out), "input/go-test-json")
 		exec, err := ScanTestOutput(shim.Config(t))
 		assert.NilError(t, err)
 
-		golden.Assert(t, shim.out.String(), tc.expectedOut)
+		golden.Assert(t, out.String(), tc.expectedOut)
 		golden.Assert(t, shim.err.String(), "input/go-test-json.err")
 
 		if tc.expected != nil {
@@ -101,43 +108,43 @@ func TestFormats_DefaultGoTestJson(t *testing.T) {
 	testCases := []testCase{
 		{
 			name:        "testname",
-			format:      testNameFormat,
+			format:      withAdapter(testNameFormat),
 			expectedOut: "format/testname.out",
 		},
 		{
 			name:        "dots-v1",
-			format:      dotsFormatV1,
+			format:      withAdapter(dotsFormatV1),
 			expectedOut: "format/dots-v1.out",
 		},
 		{
 			name:        "pkgname",
-			format:      pkgNameFormat(FormatOptions{}),
+			format:      withAdapter(pkgNameFormat(FormatOptions{})),
 			expectedOut: "format/pkgname.out",
 		},
 		{
 			name:        "pkgname-hivis",
-			format:      pkgNameFormat(FormatOptions{UseHiVisibilityIcons: true}),
+			format:      withAdapter(pkgNameFormat(FormatOptions{UseHiVisibilityIcons: true})),
 			expectedOut: "format/pkgname-hivis.out",
 		},
 		{
 			name:        "pkgname",
-			format:      pkgNameFormat(FormatOptions{HideEmptyPackages: true}),
+			format:      withAdapter(pkgNameFormat(FormatOptions{HideEmptyPackages: true})),
 			expectedOut: "format/pkgname-hide-empty.out",
 		},
 		{
 			name:        "standard-verbose",
-			format:      standardVerboseFormat,
+			format:      withAdapter(standardVerboseFormat),
 			expectedOut: "format/standard-verbose.out",
 		},
 		{
 			name:        "standard-quiet",
-			format:      standardQuietFormat,
+			format:      withAdapter(standardQuietFormat),
 			expectedOut: "format/standard-quiet.out",
 		},
 		{
 			name:        "standard-json",
 			format:      standardJSONFormat,
-			expectedOut: "format/standard-json.out",
+			expectedOut: "input/go-test-json.out",
 		},
 	}