From a9334dcc3d1e0577d5715c23637d8fe7b1e8def7 Mon Sep 17 00:00:00 2001
From: Charlie Moog <moogcharlie@gmail.com>
Date: Wed, 21 Oct 2020 23:30:21 -0500
Subject: [PATCH] Handle single file sync

---
 internal/cmd/sync.go        | 22 ++++++++------
 internal/sync/singlefile.go | 58 +++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 9 deletions(-)
 create mode 100644 internal/sync/singlefile.go

diff --git a/internal/cmd/sync.go b/internal/cmd/sync.go
index 05d9cd00..4ff3f4ec 100644
--- a/internal/cmd/sync.go
+++ b/internal/cmd/sync.go
@@ -47,6 +47,7 @@ func rsyncVersion() string {
 func makeRunSync(init *bool) func(cmd *cobra.Command, args []string) error {
 	return func(cmd *cobra.Command, args []string) error {
 		var (
+			ctx    = cmd.Context()
 			local  = args[0]
 			remote = args[1]
 		)
@@ -56,17 +57,9 @@ func makeRunSync(init *bool) func(cmd *cobra.Command, args []string) error {
 			return err
 		}
 
-		info, err := os.Stat(local)
-		if err != nil {
-			return err
-		}
-		if !info.IsDir() {
-			return xerrors.Errorf("%s must be a directory", local)
-		}
-
 		remoteTokens := strings.SplitN(remote, ":", 2)
 		if len(remoteTokens) != 2 {
-			return xerrors.New("remote misformatted")
+			return xerrors.New("remote malformatted")
 		}
 		var (
 			envName   = remoteTokens[0]
@@ -78,6 +71,17 @@ func makeRunSync(init *bool) func(cmd *cobra.Command, args []string) error {
 			return err
 		}
 
+		info, err := os.Stat(local)
+		if err != nil {
+			return err
+		}
+		if info.Mode().IsRegular() {
+			return sync.SingleFile(ctx, local, remoteDir, env, client)
+		}
+		if !info.IsDir() {
+			return xerrors.Errorf("local path must lead to a regular file or directory: %w", err)
+		}
+
 		absLocal, err := filepath.Abs(local)
 		if err != nil {
 			return xerrors.Errorf("make abs path out of %s, %s: %w", local, absLocal, err)
diff --git a/internal/sync/singlefile.go b/internal/sync/singlefile.go
new file mode 100644
index 00000000..d36a7372
--- /dev/null
+++ b/internal/sync/singlefile.go
@@ -0,0 +1,58 @@
+package sync
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"cdr.dev/coder-cli/coder-sdk"
+	"cdr.dev/wsep"
+	"golang.org/x/xerrors"
+	"nhooyr.io/websocket"
+)
+
+// SingleFile copies the given file into the remote dir or remote path of the given coder.Environment.
+func SingleFile(ctx context.Context, local, remoteDir string, env *coder.Environment, client *coder.Client) error {
+	conn, err := client.DialWsep(ctx, env)
+	if err != nil {
+		return xerrors.Errorf("dial remote execer: %w", err)
+	}
+	defer func() { _ = conn.Close(websocket.StatusNormalClosure, "normal closure") }()
+
+	if strings.HasSuffix(remoteDir, string(filepath.Separator)) {
+		remoteDir += filepath.Base(local)
+	}
+
+	execer := wsep.RemoteExecer(conn)
+	cmd := fmt.Sprintf(`[ -d %s ] && cat > %s/%s || cat > %s`, remoteDir, remoteDir, filepath.Base(local), remoteDir)
+	process, err := execer.Start(ctx, wsep.Command{
+		Command: "sh",
+		Args:    []string{"-c", cmd},
+		Stdin:   true,
+	})
+	if err != nil {
+		return xerrors.Errorf("start sync command: %w", err)
+	}
+
+	sourceFile, err := os.Open(local)
+	if err != nil {
+		return xerrors.Errorf("open source file: %w", err)
+	}
+
+	go func() { _, _ = io.Copy(ioutil.Discard, process.Stdout()) }()
+	go func() { _, _ = io.Copy(ioutil.Discard, process.Stderr()) }()
+	go func() {
+		stdin := process.Stdin()
+		defer stdin.Close()
+		_, _ = io.Copy(stdin, sourceFile)
+	}()
+
+	if err := process.Wait(); err != nil {
+		return xerrors.Errorf("copy process: %w", err)
+	}
+	return nil
+}