resolve review comments from @DavisVaughan

Author: stibu81

R/expect-setequal.R

@@ -165,7 +165,7 @@ expect_disjoint <- function(object, expected) {
     )
     msg_act <- c(
       sprintf("Actual: %s", values(act$val)),
-      sprintf("Expected: none of %s", values(exp$val)),
+      sprintf("Expected: None of %s", values(exp$val)),
       sprintf("Invalid: %s", values(act$val[act_common]))
     )
     fail(c(msg_exp, msg_act))

tests/testthat/_snaps/expect-setequal.md

@@ -151,7 +151,7 @@
       Error:
       ! Expected `x1` to be disjoint from `x2`.
       Actual: "a", "b", "c"
-      Expected: none of "c", "d"
+      Expected: None of "c", "d"
       Invalid: "c"
 
 ---
@@ -162,6 +162,17 @@
       Error:
       ! Expected `x1` to be disjoint from `x3`.
       Actual: "a", "b", "c"
-      Expected: none of "b", "c", "d"
+      Expected: None of "b", "c", "d"
       Invalid: "b", "c"
 
+---
+
+    Code
+      expect_disjoint(NA, c("a", NA))
+    Condition
+      Error:
+      ! Expected NA to be disjoint from `c("a", NA)`.
+      Actual: NA
+      Expected: None of "a", NA
+      Invalid: NA
+

tests/testthat/test-expect-setequal.R

@@ -164,4 +164,5 @@ test_that("expect_disjoint() gives useful message on failure", {
 
   expect_snapshot_failure(expect_disjoint(x1, x2))
   expect_snapshot_failure(expect_disjoint(x1, x3))
+  expect_snapshot_failure(expect_disjoint(NA, c("a", NA)))
 })