Add doc and tests for ioconn package (#291)

libplugin/ioconn/cmd.go

@@ -11,6 +11,10 @@ type cmdconn struct {
 	cmd *exec.Cmd
 }
 
+// Close closes the cmdconn and releases any associated resources.
+// It first closes the underlying connection and then kills the process if it is running.
+// If an error occurs during the closing of the connection, that error is returned.
+// If the process is running and cannot be killed, an error is returned.
 func (c *cmdconn) Close() error {
 	err := c.conn.Close()
 
@@ -21,6 +25,11 @@ func (c *cmdconn) Close() error {
 	return err
 }
 
+// DialCmd is a function that establishes a connection to a command's standard input, output, and error streams.
+// It takes a *exec.Cmd as input and returns a net.Conn, io.ReadCloser, and error.
+// The net.Conn represents the connection to the command's standard input and output streams.
+// The io.ReadCloser represents the command's standard error stream.
+// The error represents any error that occurred during the connection establishment.
 func DialCmd(cmd *exec.Cmd) (net.Conn, io.ReadCloser, error) {
 	in, err := cmd.StdoutPipe()
 	if err != nil {

libplugin/ioconn/cmd_test.go

@@ -0,0 +1,31 @@
+//go:build linux
+
+package ioconn_test
+
+import (
+	"os/exec"
+	"testing"
+
+	"github.com/tg123/sshpiper/libplugin/ioconn"
+)
+
+func TestDialCmd(t *testing.T) {
+	cmd := exec.Command("cat")
+
+	conn, _, err := ioconn.DialCmd(cmd)
+	if err != nil {
+		t.Errorf("DialCmd returned an error: %v", err)
+	}
+	defer conn.Close()
+
+	go func() {
+		_, _ = conn.Write([]byte("world"))
+	}()
+
+	buf := make([]byte, 5)
+	_, _ = conn.Read(buf)
+
+	if string(buf) != "world" {
+		t.Errorf("unexpected string read: %v", string(buf))
+	}
+}

libplugin/ioconn/conn.go

@@ -22,7 +22,19 @@ type conn struct {
 	out io.WriteCloser
 }
 
+// Dial creates a new network connection using the provided input and output streams.
+// It returns a net.Conn interface and an error, if any.
+// The input stream is used for reading data from the connection,
+// and the output stream is used for writing data to the connection.
 func Dial(in io.ReadCloser, out io.WriteCloser) (net.Conn, error) {
+	if in == nil {
+		return nil, fmt.Errorf("input stream is nil")
+	}
+
+	if out == nil {
+		return nil, fmt.Errorf("output stream is nil")
+	}
+
 	return dial(in, out), nil
 }
 
@@ -55,7 +67,7 @@ func (c *conn) Close() error {
 	}
 
 	if outerr == nil {
-		return outerr
+		return inerr
 	}
 
 	return fmt.Errorf("io close error in: %v, out: %v", inerr, outerr)

libplugin/ioconn/conn_test.go

@@ -0,0 +1,29 @@
+package ioconn_test
+
+import (
+	"io"
+	"testing"
+
+	"github.com/tg123/sshpiper/libplugin/ioconn"
+)
+
+func TestDial(t *testing.T) {
+	in, out := io.Pipe()
+
+	conn, err := ioconn.Dial(in, out)
+	if err != nil {
+		t.Errorf("Dial returned an error: %v", err)
+	}
+	defer conn.Close()
+
+	go func() {
+
+		_, _ = conn.Write([]byte("hello"))
+	}()
+	buf := make([]byte, 5)
+	_, _ = conn.Read(buf)
+
+	if string(buf) != "hello" {
+		t.Errorf("unexpected string read: %v", string(buf))
+	}
+}

libplugin/ioconn/listener.go

@@ -26,6 +26,9 @@ func (l *singleConnListener) Close() error {
 	return l.conn.Close()
 }
 
+// ListenFromSingleIO creates a net.Listener from a single input/output connection.
+// It takes an io.ReadCloser and an io.WriteCloser as parameters and returns a net.Listener and an error.
+// The returned net.Listener can be used to accept incoming connections.
 func ListenFromSingleIO(in io.ReadCloser, out io.WriteCloser) (net.Listener, error) {
 	l := &singleConnListener{
 		conn{in, out},

libplugin/ioconn/listener_test.go

@@ -0,0 +1,35 @@
+package ioconn_test
+
+import (
+	"io"
+	"testing"
+
+	"github.com/tg123/sshpiper/libplugin/ioconn"
+)
+
+func TestListenFromSingleIO(t *testing.T) {
+	in, out := io.Pipe()
+
+	l, err := ioconn.ListenFromSingleIO(in, out)
+	if err != nil {
+		t.Errorf("ListenFromSingleIO returned an error: %v", err)
+	}
+
+	conn, err := l.Accept()
+	if err != nil {
+		t.Errorf("Accept returned an error: %v", err)
+	}
+
+	defer conn.Close()
+	defer l.Close()
+
+	go func() {
+		_, _ = conn.Write([]byte("hello"))
+	}()
+
+	buf := make([]byte, 5)
+	_, _ = conn.Read(buf)
+	if string(buf) != "hello" {
+		t.Errorf("unexpected string read: %v", string(buf))
+	}
+}