1 files changed, 72 insertions, 0 deletions
diff --git a/watch_test.go b/watch_test.go
new file mode 100644
index 0000000..a1cd054
--- /dev/null
+++ b/watch_test.go
@@ -0,0 +1,72 @@
+package flyscrape_test
+
+import (
+	"errors"
+	"os"
+	"testing"
+	"time"
+
+	"flyscrape"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestWatch(t *testing.T) {
+	f := tmpfile(t)
+	defer os.Remove(f.Name())
+	write(f, "test 1")
+
+	calls := 0
+	done := make(chan struct{})
+
+	go func() {
+		err := flyscrape.Watch(f.Name(), func(s string) error {
+			calls++
+			if calls == 1 {
+				require.Equal(t, "test 1", s)
+				return nil
+			}
+			if calls == 2 {
+				require.Equal(t, "test 2", s)
+				return flyscrape.StopWatch
+			}
+			return nil
+		})
+		require.NoError(t, err)
+		close(done)
+	}()
+
+	write(f, "test 2")
+	<-done
+}
+
+func TestWatchError(t *testing.T) {
+	f := tmpfile(t)
+	defer os.Remove(f.Name())
+
+	done := make(chan struct{})
+	go func() {
+		err := flyscrape.Watch(f.Name(), func(s string) error {
+			return errors.New("test")
+		})
+		require.Error(t, err)
+		close(done)
+	}()
+
+	write(f, "test 2")
+	<-done
+}
+
+func tmpfile(t *testing.T) *os.File {
+	f, err := os.CreateTemp("", "scrape.js")
+	require.NoError(t, err)
+	return f
+}
+
+func write(f *os.File, s string) {
+	time.Sleep(10 * time.Millisecond)
+	f.Seek(0, 0)
+	f.Truncate(0)
+	f.WriteString(s)
+	f.Sync()
+}