parser/gotest: Use the new LimitedLineReader in the gotest parser

parser/gotest/gotest.go

@@ -3,7 +3,6 @@ package gotest
 
 import (
 	"bufio"
-	"bytes"
 	"fmt"
 	"io"
 	"regexp"
@@ -12,6 +11,7 @@ import (
 	"time"
 
 	"github.com/jstemmer/go-junit-report/v2/gtr"
+	"github.com/jstemmer/go-junit-report/v2/parser/gotest/internal/reader"
 )
 
 const (
@@ -130,45 +130,19 @@ func NewParser(options ...Option) *Parser {
 // Parse parses Go test output from the given io.Reader r and returns
 // gtr.Report.
 func (p *Parser) Parse(r io.Reader) (gtr.Report, error) {
+	return p.parse(reader.NewLimitedLineReader(r, maxLineSize))
+}
+
+func (p *Parser) parse(r *reader.LimitedLineReader) (gtr.Report, error) {
 	p.events = nil
-	s := bufio.NewReader(r)
 	for {
-		line, isPrefix, err := s.ReadLine()
+		line, err := r.ReadLine()
 		if err == io.EOF {
 			break
 		} else if err != nil {
 			return gtr.Report{}, err
 		}
 
-		if !isPrefix {
-			p.parseLine(string(line))
-			continue
-		}
-
-		// Line is incomplete, keep reading until we reach the end of the line.
-		var buf bytes.Buffer
-		buf.Write(line) // ignore err, always nil
-		for isPrefix {
-			line, isPrefix, err = s.ReadLine()
-			if err == io.EOF {
-				break
-			} else if err != nil {
-				return gtr.Report{}, err
-			}
-
-			if buf.Len() >= maxLineSize {
-				// Stop writing to buf if we exceed maxLineSize. We continue
-				// reading however to make sure we consume the entire line.
-				continue
-			}
-
-			buf.Write(line) // ignore err, always nil
-		}
-
-		if buf.Len() > maxLineSize {
-			buf.Truncate(maxLineSize)
-		}
-
 		// Lines that exceed bufio.MaxScanTokenSize are not expected to contain
 		// any relevant test infrastructure output, so instead of parsing them
 		// we treat them as regular output to increase performance.
@@ -177,10 +151,10 @@ func (p *Parser) Parse(r io.Reader) (gtr.Report, error) {
 		// reading lines up to bufio.MaxScanTokenSize in length. Since this
 		// turned out to be fine in almost all cases, it seemed an appropriate
 		// value to use to decide whether or not to attempt parsing this line.
-		if buf.Len() > bufio.MaxScanTokenSize {
+		if len(line) > bufio.MaxScanTokenSize {
-			p.output(buf.String())
+			p.output(line)
 		} else {
-			p.parseLine(buf.String())
+			p.parseLine(line)
 		}
 	}
 	return p.report(p.events), nil

parser/gotest/gotest_test.go

@@ -1,8 +1,6 @@
 package gotest
 
 import (
-	"bufio"
-	"bytes"
 	"fmt"
 	"strings"
 	"testing"
@@ -218,58 +216,6 @@ func TestParseLine(t *testing.T) {
 	}
 }
 
-func TestParseLargeLine(t *testing.T) {
-	tests := []struct {
-		desc      string
-		inputSize int
-	}{
-		{"small size", 128},
-		{"under buf size", 4095},
-		{"buf size", 4096},
-		{"multiple of buf size ", 4096 * 2},
-		{"not multiple of buf size", 10 * 1024},
-		{"bufio.MaxScanTokenSize", bufio.MaxScanTokenSize},
-		{"over bufio.MaxScanTokenSize", bufio.MaxScanTokenSize + 1},
-		{"under limit", maxLineSize - 1},
-		{"at limit", maxLineSize},
-		{"just over limit", maxLineSize + 1},
-		{"over limit", maxLineSize + 128},
-	}
-
-	createInput := func(lines ...string) *bytes.Buffer {
-		buf := &bytes.Buffer{}
-		buf.WriteString("=== RUN TestOne\n--- PASS: TestOne (0.00s)\n")
-		buf.WriteString(strings.Join(lines, "\n"))
-		return buf
-	}
-
-	for _, test := range tests {
-		t.Run(test.desc, func(t *testing.T) {
-			line1 := string(make([]byte, test.inputSize))
-			line2 := "other line"
-			report, err := NewParser().Parse(createInput(line1, line2))
-			if err != nil {
-				t.Fatalf("Parse() returned error %v", err)
-			} else if len(report.Packages) != 1 {
-				t.Fatalf("Parse() returned unexpected number of packages, got %d want 1.", len(report.Packages))
-			} else if len(report.Packages[0].Output) != 2 {
-				t.Fatalf("Parse() returned unexpected number of output lines, got %d want 1.", len(report.Packages[0].Output))
-			}
-
-			want := line1
-			if len(want) > maxLineSize {
-				want = want[:maxLineSize]
-			}
-			if got := report.Packages[0].Output[0]; got != want {
-				t.Fatalf("Parse() output line1 mismatch, got len %d want len %d", len(got), len(want))
-			}
-			if report.Packages[0].Output[1] != line2 {
-				t.Fatalf("Parse() output line2 mismatch, got %v want %v", report.Packages[0].Output[1], line2)
-			}
-		})
-	}
-}
-
 func TestReport(t *testing.T) {
 	events := []Event{
 		{Type: "run_test", Name: "TestOne"},