Fix .flat ignoring an errorValue in the first map element (#640)

* Fix .flat ignoring an errorValue in the first map element

* Relax .flat error tests to not match cli messages

* Retain only the discriminating .flat regression test

Author: shikokuchuo

NEWS.md

@@ -2,12 +2,13 @@
 
 #### Updates
 
+* Fixes `mirai_map()` collection option `.flat` ignoring an 'errorValue' in the first element (#639).
 * Fixes `daemon()` returning exit code 1 (idletime) instead of 2 (walltime) when `walltime` elapses while idle (#637).
 * Fixes `race_mirai()` not waiting for resolution on compute profiles set with `url` and `dispatcher = FALSE` (#635).
 * Fixes daemon crash for errors raised before evaluation begins (#633).
+* Fixes daemon cleanup not restoring options modified during evaluation (#631).
 * `mirai_map()` dispatches tasks with lower per-element overhead.
 * `everywhere()` dispatches with lower overhead, and errors upfront for a missing expression or invalid `...` arguments.
-* Fixes daemon cleanup not restoring options modified during evaluation (#631).
 * Ephemeral daemons return invisibly so that they do not print unnecessary output when this is being logged (thanks @jan-swissre, #619).
 * Requires nanonext >= 1.10.1.
 

R/map.R

@@ -232,25 +232,26 @@ print.mirai_map <- function(x, ...) {
 .flat <- compiler::compile(quote(
   if (i == 0L) {
     xi <- TRUE
-  } else if (i == 1L) {
-    typ <<- typeof(xi)
   } else {
     is_error_value(xi) && stop_m(x, i, xi)
-    typeof(xi) != typ &&
-      {
-        stop_mirai(x)
-        cli_enabled ||
-          stop(
-            sprintf("Cannot flatten outputs of differing type: %s / %s", typ, typeof(xi)),
-            call. = FALSE
+    if (typeof(xi) != typ) {
+      i == 1L ||
+        {
+          stop_mirai(x)
+          cli_enabled ||
+            stop(
+              sprintf("Cannot flatten outputs of differing type: %s / %s", typ, typeof(xi)),
+              call. = FALSE
+            )
+          cli::cli_abort(
+            c(`!` = "cannot flatten outputs of differing type: {typ} / {typeof(xi)}"),
+            location = i,
+            name = names(x)[i],
+            call = quote(mirai_map())
           )
-        cli::cli_abort(
-          c(`!` = "cannot flatten outputs of differing type: {typ} / {typeof(xi)}"),
-          location = i,
-          name = names(x)[i],
-          call = quote(mirai_map())
-        )
-      }
+        }
+      typ <<- typeof(xi)
+    }
   }
 ))
 

tests/tests.R

@@ -214,6 +214,7 @@ connection && {
   test_true(all(mres == 7L))
   test_null(names(mres))
   test_true(all(mirai_map(list(c(a = 1, b = 1, c = 1), 3), sum)[.flat] == 3))
+  test_error(mirai_map(list("a"), function(x) x + 1L)[.flat])
   test_type("language", mirai_map(list(quote(1+2)), identity)[][[1]])
   test_class("Date", mirai_map(data.frame(x = as.Date("2020-01-01")), identity)[][[1]])
   test_true(is_mirai_error(mirai_map(1:2, function(x) daemons(1))[][[1]]))