plumbing/transport: add common tests and fixes. (#136)

* plumbing/transport: add common tests and fixes.

* add common test suite for different transport implementations.
* fix different behaviour on error handling for ssh and http.
  fixes issue #123.
* support detecting unexisting repositories with SSH + GitHub/Bitbucket
  (apparently, there is no standard for all SSH servers).
* remove ssh.NewClient (only DefaultClient makes sense at the moment).
* make ssh.Client and http.Client private.
* utils/ioutil: utilities to work with io interfaces.

* * transport: test actual objects fetched, not just packfile size.

* * fix doc typo.

* * improve UploadPackRequest.IsEmpty

1 files changed, 52 insertions, 0 deletions

diff --git a/utils/ioutil/common.go b/utils/ioutil/common.go
new file mode 100644
index 0000000..13db692
--- /dev/null
+++ b/utils/ioutil/common.go
@@ -0,0 +1,52 @@
+package ioutil
+
+import (
+	"bufio"
+	"errors"
+	"io"
+)
+
+type readPeeker interface {
+	io.Reader
+	Peek(int) ([]byte, error)
+}
+
+var (
+	ErrEmptyReader = errors.New("reader is empty")
+)
+
+// NonEmptyReader takes a reader and returns it if it is not empty, or
+// `ErrEmptyReader` if it is empty. If there is an error when reading the first
+// byte of the given reader, it will be propagated.
+func NonEmptyReader(r io.Reader) (io.Reader, error) {
+	pr, ok := r.(readPeeker)
+	if !ok {
+		pr = bufio.NewReader(r)
+	}
+
+	_, err := pr.Peek(1)
+	if err == io.EOF {
+		return nil, ErrEmptyReader
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return pr, nil
+}
+
+type readCloser struct {
+	io.Reader
+	closer io.Closer
+}
+
+func (r *readCloser) Close() error {
+	return r.closer.Close()
+}
+
+// NewReadCloser creates an `io.ReadCloser` with the given `io.Reader` and
+// `io.Closer`.
+func NewReadCloser(r io.Reader, c io.Closer) io.ReadCloser {
+	return &readCloser{Reader: r, closer: c}
+}