Merge pull request bitfield#89 from gty929/small-updates

Bug fixes and improvements for corner cases

Author: bitfield

filters.go

@@ -6,6 +6,7 @@ import (
 	"container/ring"
 	"crypto/sha256"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -41,7 +42,7 @@ func (p *Pipe) Basename() *Pipe {
 func (p *Pipe) Column(col int) *Pipe {
 	return p.EachLine(func(line string, out *strings.Builder) {
 		columns := strings.Fields(line)
-		if col <= len(columns) {
+		if col > 0 && col <= len(columns) {
 			out.WriteString(columns[col-1])
 			out.WriteRune('\n')
 		}
@@ -176,7 +177,7 @@ func (p *Pipe) First(lines int) *Pipe {
 		return p
 	}
 	defer p.Close()
-	if lines == 0 {
+	if lines <= 0 {
 		return NewPipe()
 	}
 	scanner := bufio.NewScanner(p.Reader)
@@ -263,7 +264,7 @@ func (p *Pipe) Last(lines int) *Pipe {
 		return p
 	}
 	defer p.Close()
-	if lines == 0 {
+	if lines <= 0 {
 		return NewPipe()
 	}
 	scanner := bufio.NewScanner(p.Reader)
@@ -303,6 +304,9 @@ func (p *Pipe) Match(s string) *Pipe {
 // that match the specified compiled regular expression. If there is an error
 // reading the pipe, the pipe's error status is also set.
 func (p *Pipe) MatchRegexp(re *regexp.Regexp) *Pipe {
+	if re == nil { // to prevent SIGSEGV
+		return p.WithError(errors.New("nil regular expression"))
+	}
 	return p.EachLine(func(line string, out *strings.Builder) {
 		if re.MatchString(line) {
 			out.WriteString(line)
@@ -327,6 +331,9 @@ func (p *Pipe) Reject(s string) *Pipe {
 // lines that don't match the specified compiled regular expression. If there
 // is an error reading the pipe, the pipe's error status is also set.
 func (p *Pipe) RejectRegexp(re *regexp.Regexp) *Pipe {
+	if re == nil { // to prevent SIGSEGV
+		return p.WithError(errors.New("nil regular expression"))
+	}
 	return p.EachLine(func(line string, out *strings.Builder) {
 		if !re.MatchString(line) {
 			out.WriteString(line)
@@ -351,6 +358,9 @@ func (p *Pipe) Replace(search, replace string) *Pipe {
 // represents the text of the first submatch. If there is an error reading the
 // pipe, the pipe's error status is also set.
 func (p *Pipe) ReplaceRegexp(re *regexp.Regexp, replace string) *Pipe {
+	if re == nil { // to prevent SIGSEGV
+		return p.WithError(errors.New("nil regular expression"))
+	}
 	return p.EachLine(func(line string, out *strings.Builder) {
 		out.WriteString(re.ReplaceAllString(line, replace))
 		out.WriteRune('\n')

filters_test.go

@@ -51,6 +51,27 @@ func TestColumn(t *testing.T) {
 	if !bytes.Equal(got, want) {
 		t.Errorf("want %q, got %q", want, got)
 	}
+	got, err = script.File("testdata/column.input.txt").Column(0).Bytes()
+	if err != nil {
+		t.Error()
+	}
+	if !bytes.Equal(got, []byte{}) {
+		t.Errorf("want %q, got %q", want, got)
+	}
+	got, err = script.File("testdata/column.input.txt").Column(-1).Bytes()
+	if err != nil {
+		t.Error()
+	}
+	if !bytes.Equal(got, []byte{}) {
+		t.Errorf("want %q, got %q", want, got)
+	}
+	got, err = script.File("testdata/column.input.txt").Column(10).Bytes()
+	if err != nil {
+		t.Error()
+	}
+	if !bytes.Equal(got, []byte{}) {
+		t.Errorf("want %q, got %q", want, got)
+	}
 }
 
 func TestConcat(t *testing.T) {
@@ -232,6 +253,18 @@ func TestFirst(t *testing.T) {
 	if err == nil {
 		t.Error("input not closed after reading")
 	}
+	input = script.File("testdata/first.input.txt")
+	gotZero, err = input.First(-1).CountLines()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if gotZero != 0 {
+		t.Errorf("want 0 lines, got %d lines", gotZero)
+	}
+	_, err = ioutil.ReadAll(input.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
 	want, err = script.File("testdata/first.input.txt").Bytes()
 	if err != nil {
 		t.Fatal(err)
@@ -312,6 +345,18 @@ func TestLast(t *testing.T) {
 	if err == nil {
 		t.Error("input not closed after reading")
 	}
+	input = script.File("testdata/first.input.txt")
+	gotZero, err = input.Last(-1).CountLines()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if gotZero != 0 {
+		t.Errorf("want 0 lines, got %d lines", gotZero)
+	}
+	_, err = ioutil.ReadAll(input.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
 	want, err = script.File("testdata/first.input.txt").Bytes()
 	if err != nil {
 		t.Fatal(err)
@@ -350,6 +395,16 @@ func TestMatch(t *testing.T) {
 
 func TestMatchRegexp(t *testing.T) {
 	t.Parallel()
+	p := script.File("testdata/hello.txt")
+	_, err := p.MatchRegexp(nil).String()
+	if err == nil {
+		t.Error("nil regex should cause an error")
+	}
+	_, err = ioutil.ReadAll(p.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
+
 	testCases := []struct {
 		testFileName string
 		match        string
@@ -397,6 +452,16 @@ func TestReplace(t *testing.T) {
 
 func TestReplaceRegexp(t *testing.T) {
 	t.Parallel()
+	p := script.File("testdata/hello.txt")
+	_, err := p.ReplaceRegexp(nil, "").String()
+	if err == nil {
+		t.Error("nil regex should cause an error")
+	}
+	_, err = ioutil.ReadAll(p.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
+
 	testCases := []struct {
 		testFileName string
 		regexp       string
@@ -444,6 +509,16 @@ func TestReject(t *testing.T) {
 
 func TestRejectRegexp(t *testing.T) {
 	t.Parallel()
+	p := script.File("testdata/hello.txt")
+	_, err := p.RejectRegexp(nil).String()
+	if err == nil {
+		t.Error("nil regex should cause an error")
+	}
+	_, err = ioutil.ReadAll(p.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
+
 	testCases := []struct {
 		testFileName string
 		reject       string

pipes.go

@@ -75,6 +75,9 @@ func (p *Pipe) Read(b []byte) (int, error) {
 // SetError sets the pipe's error status to the specified error.
 func (p *Pipe) SetError(err error) {
 	if p != nil {
+		if err != nil {
+			p.Close()
+		}
 		p.err = err
 	}
 }

pipes_test.go

@@ -26,6 +26,25 @@ func TestWithReader(t *testing.T) {
 	}
 }
 
+func TestWithError(t *testing.T) {
+	t.Parallel()
+	p := script.File("testdata/empty.txt")
+	want := "fake error"
+	_, gotErr := p.WithError(errors.New(want)).String()
+	if gotErr.Error() != "fake error" {
+		t.Errorf("want %q, got %q", want, gotErr.Error())
+	}
+	_, err := ioutil.ReadAll(p.Reader)
+	if err == nil {
+		t.Error("input not closed after reading")
+	}
+	p = script.File("testdata/empty.txt")
+	_, gotErr = p.WithError(nil).String()
+	if gotErr != nil {
+		t.Errorf("got unexpected error: %q", gotErr.Error())
+	}
+}
+
 func TestWithStdout(t *testing.T) {
 	t.Parallel()
 	buf := &bytes.Buffer{}
@@ -126,6 +145,8 @@ func doMethodsOnPipe(t *testing.T, p *script.Pipe, kind string) {
 	p.Error()
 	action = "Exec()"
 	p.Exec("bogus")
+	action = "ExecForEach()"
+	p.ExecForEach("bogus")
 	action = "ExitStatus()"
 	p.ExitStatus()
 	action = "First()"
@@ -142,6 +163,10 @@ func doMethodsOnPipe(t *testing.T, p *script.Pipe, kind string) {
 	p.MatchRegexp(regexp.MustCompile(".*"))
 	action = "Read()"
 	p.Read([]byte{})
+	action = "Reject()"
+	p.Reject("")
+	action = "RejectRegexp"
+	p.RejectRegexp(regexp.MustCompile(".*"))
 	action = "Replace()"
 	p.Replace("old", "new")
 	action = "ReplaceRegexp()"

testdata/freq.golden.txt

@@ -1,4 +1,4 @@
 10 apple
  4 banana
- 2 orange
+ 4 orange
  1 kumquat

testdata/freq.input.txt

@@ -6,11 +6,13 @@ apple
 orange
 kumquat
 apple
+orange
 apple
 banana
 banana
 apple
 apple
+orange
 apple
 apple
 apple