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|
package parallel
import (
"bytes"
"errors"
"io"
"strings"
"testing"
)
var errFake1 = errors.New("fake error #1")
func StringSliceContains(sl []string, s string) bool {
for _, v := range sl {
if s == v {
return true
}
}
return false
}
// LinesEqualSeparator returns true, if every line in a, when separated by
// separator, can be found in b.
func LinesEqualSeparator(a, b, sep string) bool {
al := strings.Split(a, sep)
bl := strings.Split(b, sep)
if len(al) != len(bl) {
return false
}
for _, line := range al {
if !StringSliceContains(bl, line) {
return false
}
}
return true
}
// LinesEqual returns true, if every line in a, when separated by a newline, can be found in b.
func LinesEqual(a, b string) bool {
return LinesEqualSeparator(a, b, "\n")
}
func TestSimple(t *testing.T) {
var cases = []struct {
about string
r io.Reader
expected string
f func([]byte) ([]byte, error)
err error
}{
{
about: `No input produces no output.`,
r: strings.NewReader(""),
expected: "",
f: func(b []byte) ([]byte, error) { return []byte{}, nil },
err: nil,
},
{
about: `Order is not guaranteed.`,
r: strings.NewReader("a\nb\n"),
expected: "B\nA\n",
f: func(b []byte) ([]byte, error) { return bytes.ToUpper(b), nil },
err: nil,
},
{
about: `Like grep, we can filter out items by returning nothing.`,
r: strings.NewReader("a\nb\n"),
expected: "B\n",
f: func(b []byte) ([]byte, error) {
if strings.TrimSpace(string(b)) == "a" {
return []byte{}, nil
}
return bytes.ToUpper(b), nil
},
err: nil,
},
{
about: `Empty lines skipped.`,
r: strings.NewReader("a\na\na\na\n\n\nb\n"),
expected: "B\n",
f: func(b []byte) ([]byte, error) {
if strings.TrimSpace(string(b)) == "a" {
return []byte{}, nil
}
return bytes.ToUpper(b), nil
},
err: nil,
},
{
about: `On empty input, the transformer func is never called.`,
r: strings.NewReader(""),
expected: "",
f: func(b []byte) ([]byte, error) {
return nil, errFake1
},
err: nil,
},
{
about: `Error does not come through, if all lines are skipped.`,
r: strings.NewReader("\n"),
expected: "",
f: func(b []byte) ([]byte, error) {
return nil, errFake1
},
err: nil,
},
}
for _, c := range cases {
var buf bytes.Buffer
p := NewProcessor(c.r, &buf, c.f)
err := p.Run()
if err != c.err {
t.Errorf("p.Run: got %v, want %v", err, c.err)
}
if !LinesEqual(buf.String(), c.expected) {
t.Errorf("p.Run: got %v, want %v", buf.String(), c.expected)
}
}
}
|
