Fix bugs in BinaryIO creator

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>

cio/io_test.go

@@ -23,6 +23,7 @@ import (
 	"context"
 	"io"
 	"io/ioutil"
+	"net/url"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -153,3 +154,26 @@ func initProducers(t *testing.T, producers producers, stdout, stderr string) {
 	assert.NilError(t, err)
 	assert.NilError(t, producers.Stderr.Close())
 }
+
+func TestBinaryIOArgs(t *testing.T) {
+	res, err := BinaryIO("/file.bin", map[string]string{"id": "1"})("")
+	assert.NilError(t, err)
+	assert.Equal(t, "binary:///file.bin?id=1", res.Config().Stdout)
+	assert.Equal(t, "binary:///file.bin?id=1", res.Config().Stderr)
+}
+
+func TestBinaryIOAbsolutePath(t *testing.T) {
+	res, err := BinaryIO("/full/path/bin", nil)("!")
+	assert.NilError(t, err)
+
+	// Test parse back
+	parsed, err := url.Parse(res.Config().Stdout)
+	assert.NilError(t, err)
+	assert.Equal(t, "binary", parsed.Scheme)
+	assert.Equal(t, "/full/path/bin", parsed.Path)
+}
+
+func TestBinaryIOFailOnRelativePath(t *testing.T) {
+	_, err := BinaryIO("./bin", nil)("!")
+	assert.Error(t, err, "absolute path needed")
+}