feat(cli): add exp task send (#19922)

Closes https://github.com/coder/internal/issues/895

---------

Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>

cli/exp_task_send.go

@@ -0,0 +1,78 @@
+package cli
+
+import (
+	"io"
+
+	"github.com/google/uuid"
+	"golang.org/x/xerrors"
+
+	"github.com/coder/coder/v2/codersdk"
+	"github.com/coder/serpent"
+)
+
+func (r *RootCmd) taskSend() *serpent.Command {
+	var stdin bool
+
+	cmd := &serpent.Command{
+		Use:        "send <task> [<input> | --stdin]",
+		Short:      "Send input to a task",
+		Middleware: serpent.RequireRangeArgs(1, 2),
+		Options: serpent.OptionSet{
+			{
+				Name:        "stdin",
+				Flag:        "stdin",
+				Description: "Reads the input from stdin.",
+				Value:       serpent.BoolOf(&stdin),
+			},
+		},
+		Handler: func(inv *serpent.Invocation) error {
+			client, err := r.InitClient(inv)
+			if err != nil {
+				return err
+			}
+
+			var (
+				ctx  = inv.Context()
+				exp  = codersdk.NewExperimentalClient(client)
+				task = inv.Args[0]
+
+				taskInput string
+				taskID    uuid.UUID
+			)
+
+			if stdin {
+				bytes, err := io.ReadAll(inv.Stdin)
+				if err != nil {
+					return xerrors.Errorf("reading stdio: %w", err)
+				}
+
+				taskInput = string(bytes)
+			} else {
+				if len(inv.Args) != 2 {
+					return xerrors.Errorf("expected an input for the task")
+				}
+
+				taskInput = inv.Args[1]
+			}
+
+			if id, err := uuid.Parse(task); err == nil {
+				taskID = id
+			} else {
+				ws, err := namedWorkspace(ctx, client, task)
+				if err != nil {
+					return xerrors.Errorf("resolve task: %w", err)
+				}
+
+				taskID = ws.ID
+			}
+
+			if err = exp.TaskSend(ctx, codersdk.Me, taskID, codersdk.TaskSendRequest{Input: taskInput}); err != nil {
+				return xerrors.Errorf("send input to task: %w", err)
+			}
+
+			return nil
+		},
+	}
+
+	return cmd
+}