Correct expect_setequal() failure message (#1837)

Fixes #1835

NEWS.md

@@ -1,5 +1,8 @@
 # testthat (development version)
 
+* `expect_setequal()` correctly displays results when only one of actual and
+  expected is missing values (#1835).
+
 # testthat 3.1.10
 
 * Fix for upcoming R-devel release.

R/expect-setequal.R

@@ -41,10 +41,10 @@ expect_setequal <- function(object, expected) {
   if (any(exp_miss) || any(act_miss)) {
     fail(paste0(
       act$lab, " (`actual`) and ", exp$lab, " (`expected`) don't have the same values.\n",
-      if (any(exp_miss))
-        paste0("* Only in `actual`:   ",  values(act$val[act_miss]), "\n"),
       if (any(act_miss))
-        paste0("* Only in `expected`: ",  values(exp$val[exp_miss]), "\n")
+        paste0("* Only in `expected`: ",  values(act$val[act_miss]), "\n"),
+      if (any(exp_miss))
+        paste0("* Only in `actual`: ",  values(exp$val[exp_miss]), "\n")
     ))
   } else {
     succeed()

tests/testthat/_snaps/expect-setequal.md

@@ -1,15 +1,26 @@
-# useful message on faillure
+# useful message on failure
 
-    `x1` (`actual`) and `x2` (`expected`) don't have the same values.
-    * Only in `actual`:   "a"
-    * Only in `expected`: "c"
+    1:2 (`actual`) and 2 (`expected`) don't have the same values.
+    * Only in `expected`: 1
 
 
 ---
 
-    `y1` (`actual`) and `y2` (`expected`) don't have the same values.
-    * Only in `actual`:   1
-    * Only in `expected`: 4, 5, 6, 7, 8, 9, 10, 11, 12, ...
+    2 (`actual`) and 2:3 (`expected`) don't have the same values.
+    * Only in `actual`: 3
+
+
+---
+
+    1:2 (`actual`) and 2:3 (`expected`) don't have the same values.
+    * Only in `expected`: 1
+    * Only in `actual`: 3
+
+
+# truncates long vectors
+
+    1:2 (`actual`) and 1:50 (`expected`) don't have the same values.
+    * Only in `actual`: 3, 4, 5, 6, 7, 8, 9, 10, 11, ...
 
 
 # expect_contains() gives useful message on failure

tests/testthat/test-expect-setequal.R

@@ -23,14 +23,14 @@ test_that("error for non-vectors", {
   expect_error(expect_setequal(sum, sum), "be vectors")
 })
 
-test_that("useful message on faillure", {
-  x1 <- c("a", "b")
-  x2 <- c("b", "c")
-  y1 <- 1:3
-  y2 <- 2:50
+test_that("useful message on failure", {
+  expect_snapshot_failure(expect_setequal(1:2, 2))
+  expect_snapshot_failure(expect_setequal(2, 2:3))
+  expect_snapshot_failure(expect_setequal(1:2, 2:3))
+})
 
-  expect_snapshot_failure(expect_setequal(x1, x2))
-  expect_snapshot_failure(expect_setequal(y1, y2))
+test_that("truncates long vectors", {
+  expect_snapshot_failure(expect_setequal(1:2, 1:50))
 })
 
 # mapequal ----------------------------------------------------------------