ssh: add tests for explicit ~

coder · spikecurtis · Mar 17, 2025 · Feb 19, 2025 · Feb 24, 2025 · Mar 7, 2025
commit 36d4929f47730ccb5d68b305319489f59ccc926f
diff --git a/.gitignore b/.gitignore
@@ -1,2 +1,3 @@
 # Build output
 /build/
+.idea/
diff --git a/pkg/agent/dial.go b/pkg/agent/dial.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"github.com/mutagen-io/mutagen/pkg/prompting"
 	"io"
 	"strings"
 	"time"
@@ -14,7 +15,6 @@ import (
 	"github.com/mutagen-io/mutagen/pkg/logging"
 	"github.com/mutagen-io/mutagen/pkg/mutagen"
 	"github.com/mutagen-io/mutagen/pkg/platform/terminal"
-	"github.com/mutagen-io/mutagen/pkg/prompting"
 	streampkg "github.com/mutagen-io/mutagen/pkg/stream"
 )
 
@@ -34,49 +34,7 @@ const (
 // installation should be attempted and whether or not the remote environment is
 // cmd.exe-based.
 func connect(logger *logging.Logger, transport Transport, mode, prompter string, cmdExe bool) (io.ReadWriteCloser, bool, bool, error) {
-	// Compute the agent invocation command, relative to the user's home
-	// directory on the remote. Unless we have reason to assume that this is a
-	// cmd.exe environment, we construct a path using forward slashes. This will
-	// work for all POSIX systems and POSIX-like environments on Windows. If we
-	// know we're hitting a cmd.exe environment, then we use backslashes,
-	// otherwise the invocation won't work. Watching for cmd.exe to fail on
-	// commands with forward slashes is actually the way that we detect cmd.exe
-	// environments.
-	//
-	// HACK: We're assuming that none of these path components have spaces in
-	// them, but since we control all of them, this is probably okay.
-	//
-	// HACK: When invoking on Windows systems (whether inside a POSIX
-	// environment or cmd.exe), we can leave the "exe" suffix off the target
-	// name. Fortunately this allows us to also avoid having to try the
-	// combination of forward slashes + ".exe" for Windows POSIX environments.
-	//
-	// HACK: When invoking on cmd.exe, we leave off the ~ prefix, since cmd.exe
-	// doesn't recognize it. In most cases the initial working directory for SSH
-	// commands is the home directory, but when possible we try to be explicit,
-	// to work around systems that use a different directory, such as Coder
-	// workspaces, which allow different initial working directories to be
-	// configured.
-	pathSeparator := "/"
-	pathComponents := []string{filesystem.HomeDirectorySpecial}
-	if cmdExe {
-		pathSeparator = "\\"
-		pathComponents = nil
-	}
-	dataDirectoryName := filesystem.MutagenDataDirectoryName
-	if mutagen.DevelopmentModeEnabled {
-		dataDirectoryName = filesystem.MutagenDataDirectoryDevelopmentName
-	}
-	pathComponents = append(pathComponents,
-		dataDirectoryName,
-		filesystem.MutagenAgentsDirectoryName,
-		mutagen.Version,
-		BaseName,
-	)
-	agentInvocationPath := strings.Join(pathComponents, pathSeparator)
-
-	// Compute the command to invoke.
-	command := fmt.Sprintf("%s %s --%s=%s", agentInvocationPath, mode, FlagLogLevel, logger.Level())
+	command := fmt.Sprintf("%s %s --%s=%s", agentInvocationPath(cmdExe), mode, FlagLogLevel, logger.Level())
 
 	// Set up (but do not start) an agent process.
 	message := "Connecting to agent (POSIX)..."
@@ -186,6 +144,49 @@ func connect(logger *logging.Logger, transport Transport, mode, prompter string,
 	return stream, false, false, nil
 }
 
+// agentInvocationPath computes the agent invocation path, relative to the user's home
+// directory on the remote.
+func agentInvocationPath(cmdExe bool) string {
+	// Unless we have reason to assume that this is a cmd.exe environment, we
+	// construct a path using forward slashes. This will work for all POSIX
+	// systems and POSIX-like environments on Windows. If we know we're hitting
+	// a cmd.exe environment, then we use backslashes, otherwise the invocation
+	// won't work. Watching for cmd.exe to fail on commands with forward slashes
+	// is actually the way that we detect cmd.exe environments.
+	//
+	// HACK: We're assuming that none of these path components have spaces in
+	// them, but since we control all of them, this is probably okay.
+	//
+	// HACK: When invoking on Windows systems (whether inside a POSIX
+	// environment or cmd.exe), we can leave the "exe" suffix off the target
+	// name. Fortunately this allows us to also avoid having to try the
+	// combination of forward slashes + ".exe" for Windows POSIX environments.
+	//
+	// HACK: When invoking on cmd.exe, we leave off the ~ prefix, since cmd.exe
+	// doesn't recognize it. In most cases the initial working directory for SSH
+	// commands is the home directory, but when possible we try to be explicit,
+	// to work around systems that use a different directory, such as Coder
+	// workspaces, which allow different initial working directories to be
+	// configured.
+	pathSeparator := "/"
+	pathComponents := []string{filesystem.HomeDirectorySpecial}
+	if cmdExe {
+		pathSeparator = "\\"
+		pathComponents = nil
+	}
+	dataDirectoryName := filesystem.MutagenDataDirectoryName
+	if mutagen.DevelopmentModeEnabled {
+		dataDirectoryName = filesystem.MutagenDataDirectoryDevelopmentName
+	}
+	pathComponents = append(pathComponents,
+		dataDirectoryName,
+		filesystem.MutagenAgentsDirectoryName,
+		mutagen.Version,
+		BaseName,
+	)
+	return strings.Join(pathComponents, pathSeparator)
+}
+
 // Dial connects to an agent-based endpoint using the specified transport,
 // connection mode, and prompter.
 func Dial(logger *logging.Logger, transport Transport, mode, prompter string) (io.ReadWriteCloser, error) {

diff --git a/pkg/agent/dial_test.go b/pkg/agent/dial_test.go
@@ -1,3 +1,21 @@
 package agent
 
-// TODO: Implement.
+import (
+	"fmt"
+	"github.com/mutagen-io/mutagen/pkg/mutagen"
+	"testing"
+)
+
+func TestAgentInvocationPath(t *testing.T) {
+	path := agentInvocationPath(false)
+	expected := fmt.Sprintf("~/.mutagen/agents/%s/mutagen-agent", mutagen.Version)
+	if path != expected {
+		t.Errorf("Invocation path cmdExe=false, expected %s, got %s", expected, path)
+	}
+
+	path = agentInvocationPath(true)
+	expected = fmt.Sprintf(".mutagen\\agents\\%s\\mutagen-agent", mutagen.Version)
+	if path != expected {
+		t.Errorf("Invocation path cmdExe=true, expected %s, got %s", expected, path)
+	}
+}
diff --git a/pkg/agent/install.go b/pkg/agent/install.go
@@ -111,13 +111,7 @@ func install(logger *logging.Logger, transport Transport, prompter string, cmdEx
 	if err := prompting.Message(prompter, "Installing agent..."); err != nil {
 		return fmt.Errorf("unable to message prompter: %w", err)
 	}
-	var installCommand string
-	if posix && cmdExe {
-		// TODO: is this path even possible?
-		installCommand = fmt.Sprintf("./%s %s", fullRemotePath, CommandInstall)
-	} else {
-		installCommand = fmt.Sprintf("%s %s", fullRemotePath, CommandInstall)
-	}
+	installCommand := fmt.Sprintf("%s %s", fullRemotePath, CommandInstall)
 	if err := run(transport, installCommand); err != nil {
 		return fmt.Errorf("unable to invoke agent installation: %w", err)
 	}