Fix #146

NEWS.md

@@ -3,6 +3,7 @@
 * Require `nanonext` >= 0.12.0 and `mirai` >= 0.12.0.
 * Return to always re-launching backlogged inactive workers (#79, https://github.com/shikokuchuo/mirai/discussions/95).
 * Implement `push_backlog()` and `pop_backlog()` to manage cases when it is not desirable to push to saturated controllers (https://github.com/ropensci/targets/issues/1220).
+* Invisibly return the `mirai` object of a task pushed to the controller. This allows users to interact with the task directly, e.g. to create a promise object with `promises::as.promise()` (#146, @jcheng5).
 
 # crew 0.8.0
 

R/crew_controller.R

@@ -337,7 +337,9 @@ crew_class_controller <- R6::R6Class(
       invisible()
     },
     #' @description Push a task to the head of the task list.
-    #' @return `NULL` (invisibly).
+    #' @return Invisibly return the `mirai` object of the pushed task.
+    #'   This allows you to interact with the task directly, e.g.
+    #'   to create a promise object with `promises::as.promise()`.
     #' @param command Language object with R code to run.
     #' @param data Named list of local data objects in the
     #'   evaluation environment.
@@ -444,7 +446,7 @@ crew_class_controller <- R6::R6Class(
       if (scale) {
         .subset2(self, "scale")(throttle = throttle)
       }
-      invisible()
+      invisible(task)
     },
     #' @description Apply a single command to multiple inputs.
     #' @details `map()` cannot be used unless all prior tasks are

R/crew_controller_group.R

@@ -273,7 +273,9 @@ crew_class_controller_group <- R6::R6Class(
       walk(control, ~.x$scale(throttle = throttle))
     },
     #' @description Push a task to the head of the task list.
-    #' @return `NULL` (invisibly).
+    #' @return Invisibly return the `mirai` object of the pushed task.
+    #'   This allows you to interact with the task directly, e.g.
+    #'   to create a promise object with `promises::as.promise()`.
     #' @param command Language object with R code to run.
     #' @param data Named list of local data objects in the
     #'   evaluation environment.

tests/testthat/test-crew_controller_group.R

@@ -72,12 +72,13 @@ crew_test("crew_controller_group()", {
   )
   expect_null(x$pop())
   # substitute = TRUE # nolint
-  x$push(
+  task <- x$push(
     command = ps::ps_pid(),
     name = "task_pid",
     controller = "b",
     save_command = TRUE
   )
+  expect_s3_class(task, "mirai")
   expect_false(x$empty())
   expect_true(x$empty(controllers = "a"))
   expect_false(x$empty(controllers = "b"))

tests/testthat/test-crew_controller_local.R

@@ -45,11 +45,12 @@ crew_test("crew_controller_local()", {
   # first task
   expect_equal(x$pushed, 0L)
   expect_equal(x$popped, 0L)
-  x$push(
+  task <- x$push(
     command = Sys.getenv("CREW_INSTANCE"),
     name = "task",
     save_command = TRUE
   )
+  expect_s3_class(task, "mirai")
   expect_equal(x$pushed, 1L)
   expect_equal(x$popped, 0L)
   expect_false(x$empty())