feat(ansi): support OSC 7 notify working directory (#274)

* feat(ansi): support OSC 7 notify working directory

* Fix extra ;

* Remove unused param

* Add links

* Update ansi/cwd.go

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

* Use list of strings

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

* Apply suggestions from code review

* fix import

---------

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

ansi/cwd.go

@@ -0,0 +1,26 @@
+package ansi
+
+import (
+	"net/url"
+	"path"
+)
+
+// NotifyWorkingDirectory returns a sequence that notifies the terminal
+// of the current working directory.
+//
+//	OSC 7 ; Pt BEL
+//
+// Where Pt is a URL in the format "file://[host]/[path]".
+// Set host to "localhost" if this is a path on the local computer.
+//
+// See: https://wezfurlong.org/wezterm/shell-integration.html#osc-7-escape-sequence-to-set-the-working-directory
+// See: https://iterm2.com/documentation-escape-codes.html#:~:text=RemoteHost%20and%20CurrentDir%3A-,OSC%207,-%3B%20%5BPs%5D%20ST
+func NotifyWorkingDirectory(host string, paths ...string) string {
+	path := path.Join(paths...)
+	u := &url.URL{
+		Scheme: "file",
+		Host:   host,
+		Path:   path,
+	}
+	return "\x1b]7;" + u.String() + "\x07"
+}

ansi/cwd_test.go

@@ -0,0 +1,21 @@
+package ansi_test
+
+import (
+	"testing"
+
+	"github.com/charmbracelet/x/ansi"
+)
+
+func TestNotifyWorkingDirectory_LocalFile(t *testing.T) {
+	h := ansi.NotifyWorkingDirectory("localhost", "path", "to", "file")
+	if h != "\x1b]7;file://localhost/path/to/file\x07" {
+		t.Errorf("Unexpected url: %s", h)
+	}
+}
+
+func TestNotifyWorkingDirectory_RemoteFile(t *testing.T) {
+	h := ansi.NotifyWorkingDirectory("example.com", "path", "to", "file")
+	if h != "\x1b]7;file://example.com/path/to/file\x07" {
+		t.Errorf("Unexpected url: %s", h)
+	}
+}