textedit/lib_test.go

package textedit_test

import (
	"bytes"
	"code.squareroundforest.org/arpio/textedit"
	"errors"
	"io"
	"testing"
)

var errTest = errors.New("test")

type failingWriter struct {
	out  io.Writer
	fail bool
}

func (w *failingWriter) Write(p []byte) (int, error) {
	if w.fail {
		return 0, errTest
	}

	return w.out.Write(p)
}

func TestNoop(t *testing.T) {
	t.Run("editor", func(t *testing.T) {
		var b bytes.Buffer
		w := textedit.New(&b, textedit.Func(nil, func(int) []rune { return nil }))
		if _, err := w.Write([]byte("foo bar baz")); err != nil {
			t.Fatal(err)
		}

		if err := w.Flush(); err != nil {
			t.Fatal(err)
		}

		if b.String() != "foo bar baz" {
			t.Fatal(b.String())
		}
	})

	t.Run("release", func(t *testing.T) {
		var b bytes.Buffer
		w := textedit.New(&b, textedit.Func(func(r rune, s int) ([]rune, int) { return []rune{r}, 9 }, nil))
		if _, err := w.Write([]byte("foo bar baz")); err != nil {
			t.Fatal(err)
		}

		if err := w.Flush(); err != nil {
			t.Fatal(err)
		}

		if b.String() != "foo bar baz" {
			t.Fatal(b.String())
		}
	})
}

func TestWriteRune(t *testing.T) {
	var b bytes.Buffer
	w := textedit.New(&b, textedit.Replace("o", "e"))
	for _, r := range []rune("foo bar baz") {
		if _, err := w.WriteRune(r); err != nil {
			t.Fatal(err)
		}
	}

	if err := w.Flush(); err != nil {
		t.Fatal(err)
	}

	if b.String() != "fee bar baz" {
		t.Fatal(b.String())
	}
}

func TestFailingWriter(t *testing.T) {
	t.Run("after write", func(t *testing.T) {
		var b bytes.Buffer
		fw := failingWriter{out: &b}
		w := textedit.New(&fw, textedit.Replace("o", "e"))
		if _, err := w.Write([]byte("foo ")); err != nil {
			t.Fatal(err)
		}

		fw.fail = true
		if _, err := w.Write([]byte("bar")); !errors.Is(err, errTest) {
			t.Fatal("failed to fail with the right error", err)
		}

		if _, err := w.Write([]byte("bar")); !errors.Is(err, errTest) {
			t.Fatal("failed to fail with the right error", err)
		}

		if err := w.Flush(); !errors.Is(err, errTest) {
			t.Fatal("failed to fail with the right error", err)
		}
	})

	t.Run("after flush", func(t *testing.T) {
		var b bytes.Buffer
		fw := failingWriter{out: &b}
		w := textedit.New(&fw, textedit.Replace("o", "e"))
		if _, err := w.Write([]byte("foo bar")); err != nil {
			t.Fatal(err)
		}

		fw.fail = true
		if err := w.Flush(); !errors.Is(err, errTest) {
			t.Fatal("failed to fail with the right error", err)
		}
	})
}