Add per-task terminals over WebSocket with an xterm.js Terminal tab

2026-10-15 12:06:50 -07:00
parent 37bf1b60a7
commit ff22f33025
33 changed files with 1600 additions and 167 deletions
@@ -0,0 +1,147 @@
+package server_test
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/coder/websocket"
+
+	"g.fc.run/misc/byre/internal/api"
+)
+
+type termConn struct {
+	t    *testing.T
+	conn *websocket.Conn
+	seen strings.Builder
+}
+
+func (h *harness) openTerminal(taskID string) *termConn {
+	h.t.Helper()
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	header := http.Header{}
+	header.Set("Tailscale-User-Login", login)
+	header.Set("Tailscale-User-Name", "Alice")
+	url := "ws" + strings.TrimPrefix(h.url, "http") + "/api/tasks/" + taskID + "/terminal?cols=80&rows=24"
+	conn, _, err := websocket.Dial(ctx, url, &websocket.DialOptions{HTTPHeader: header})
+	if err != nil {
+		h.t.Fatalf("dial terminal: %v", err)
+	}
+	h.t.Cleanup(func() { conn.CloseNow() })
+	return &termConn{t: h.t, conn: conn}
+}
+
+func (c *termConn) send(text string) {
+	c.t.Helper()
+	err := c.conn.Write(context.Background(), websocket.MessageBinary, []byte(text))
+	if err != nil {
+		c.t.Fatalf("write terminal: %v", err)
+	}
+}
+
+func (c *termConn) waitFor(want string) {
+	c.t.Helper()
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	for !strings.Contains(c.seen.String(), want) {
+		_, b, err := c.conn.Read(ctx)
+		if err != nil {
+			c.t.Fatalf("waiting for %q: %v; seen %q", want, err, c.seen.String())
+		}
+		c.seen.Write(b)
+	}
+}
+
+func (c *termConn) waitClosed() websocket.CloseError {
+	c.t.Helper()
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	for {
+		_, b, err := c.conn.Read(ctx)
+		if err == nil {
+			c.seen.Write(b)
+			continue
+		}
+		ce := websocket.CloseError{}
+		if !errors.As(err, &ce) {
+			c.t.Fatalf("want a close frame, got %v", err)
+		}
+		return ce
+	}
+}
+
+func TestTaskTerminal(t *testing.T) {
+	t.Setenv("SHELL", "/bin/sh")
+	h := newHarness(t)
+	p := h.createProject("demo")
+	task := api.Task{}
+	h.do("POST", "/api/projects/"+p.Id+"/tasks", api.TaskCreate{Title: "terminal"}, &task)
+
+	wt, err := filepath.EvalSymlinks(task.WorktreePath)
+	if err != nil {
+		t.Fatalf("resolve worktree: %v", err)
+	}
+	header := http.Header{}
+	header.Set("Tailscale-User-Login", login)
+	header.Set("Tailscale-User-Name", "Alice")
+	header.Set("Origin", "https://elsewhere.example")
+	_, resp, err := websocket.Dial(context.Background(), "ws"+strings.TrimPrefix(h.url, "http")+"/api/tasks/"+task.Id+"/terminal?cols=80&rows=24", &websocket.DialOptions{HTTPHeader: header})
+	if err == nil || resp == nil || resp.StatusCode != http.StatusForbidden {
+		t.Fatalf("cross-origin terminal: want 403, got %v %v", resp, err)
+	}
+
+	a := h.openTerminal(task.Id)
+	a.send("echo \"$PORT:$(pwd -P)\"\n")
+	a.waitFor(fmt.Sprintf("%d:%s", task.PortBase, wt))
+	a.send("echo byre-$((40+2))\n")
+	a.waitFor("byre-42")
+
+	size, err := json.Marshal(api.TerminalSize{Cols: 100, Rows: 30})
+	if err != nil {
+		t.Fatalf("marshal size: %v", err)
+	}
+	err = a.conn.Write(context.Background(), websocket.MessageText, size)
+	if err != nil {
+		t.Fatalf("resize: %v", err)
+	}
+	a.send("stty size\n")
+	a.waitFor("30 100")
+
+	b := h.openTerminal(task.Id)
+	b.waitFor("byre-42")
+	b.send("exit\n")
+	for _, c := range []*termConn{a, b} {
+		ce := c.waitClosed()
+		if ce.Code != 4000 || ce.Reason != "exit status 0" {
+			t.Fatalf("close after exit: %d %q", ce.Code, ce.Reason)
+		}
+	}
+
+	c := h.openTerminal(task.Id)
+	c.send("echo fresh\n")
+	c.waitFor("fresh")
+	if strings.Contains(c.seen.String(), "byre-42") {
+		t.Fatalf("new shell replayed the old one's output: %q", c.seen.String())
+	}
+
+	code := h.do("POST", "/api/tasks/"+task.Id+"/discard", nil, nil)
+	if code != http.StatusOK {
+		t.Fatalf("discard: %d", code)
+	}
+	ce := c.waitClosed()
+	if ce.Code != 4000 {
+		t.Fatalf("close after discard: %d %q", ce.Code, ce.Reason)
+	}
+
+	code = h.do("GET", "/api/tasks/"+task.Id+"/terminal?cols=80&rows=24", nil, nil)
+	if code != http.StatusConflict {
+		t.Fatalf("terminal of a discarded task: want 409, got %d", code)
+	}
+}