add expect_not_contains() (#1851)

Author: stibu81

NAMESPACE

@@ -113,6 +113,7 @@ export(expect_no_match)
 export(expect_no_message)
 export(expect_no_success)
 export(expect_no_warning)
+export(expect_not_contains)
 export(expect_null)
 export(expect_output)
 export(expect_output_file)

R/expect-setequal.R

@@ -4,6 +4,8 @@
 #'    and that every element of `y` occurs in `x`.
 #' * `expect_contains(x, y)` tests that `x` contains every element of `y`
 #'   (i.e. `y` is a subset of `x`).
+#' * `expect_not_contains(x, y)` tests that `x` contains none of the elements
+#'   of `y` (i.e. `y` is disjoint from `x`).
 #' * `expect_in(x, y)` tests every element of `x` is in `y`
 #'   (i.e. `x` is a subset of `y`).
 #' * `expect_mapequal(x, y)` treats lists as if they are mappings between names
@@ -117,6 +119,33 @@ expect_contains <- function(object, expected) {
   pass(act$val)
 }
 
+#' @export
+#' @rdname expect_setequal
+expect_not_contains <- function(object, expected) {
+  act <- quasi_label(enquo(object))
+  exp <- quasi_label(enquo(expected))
+
+  check_vector(object)
+  check_vector(expected)
+
+  exp_found <- exp$val %in% act$val
+  if (any(exp_found)) {
+    msg_exp <- sprintf(
+      "Expected %s to contain none of the values in %s.",
+      act$lab,
+      exp$lab
+    )
+    msg_act <- c(
+      sprintf("Actual: %s", values(act$val)),
+      sprintf("Expected: none of %s", values(exp$val)),
+      sprintf("Found: %s", values(exp$val[exp_found]))
+    )
+    fail(c(msg_exp, msg_act))
+  }
+
+  pass(act$val)
+}
+
 #' @export
 #' @rdname expect_setequal
 expect_in <- function(object, expected) {

man/expect_setequal.Rd

@@ -121,6 +121,28 @@
       Expected: "d", "e"
       Missing: "d", "e"
 
+# expect_not_contains() gives useful message on failure
+
+    Code
+      expect_not_contains(x1, x2)
+    Condition
+      Error:
+      ! Expected `x1` to contain none of the values in `x2`.
+      Actual: "a", "b", "c"
+      Expected: none of "c", "d"
+      Found: "c"
+
+---
+
+    Code
+      expect_not_contains(x1, x3)
+    Condition
+      Error:
+      ! Expected `x1` to contain none of the values in `x3`.
+      Actual: "a", "b", "c"
+      Expected: none of "b", "c", "d"
+      Found: "b", "c"
+
 # expect_in() gives useful message on failure
 
     Code

tests/testthat/_snaps/expect-setequal.md

@@ -131,6 +131,23 @@ test_that("expect_contains() gives useful message on failure", {
   expect_snapshot_failure(expect_contains(x1, x3))
 })
 
+# not_contains ----------------------------------------------------------------
+
+test_that("expect_not_contains() succeeds when appropriate", {
+  expect_success(expect_not_contains(letters, 1))
+  expect_success(expect_not_contains(letters, LETTERS))
+  expect_success(expect_not_contains(letters, character()))
+})
+
+test_that("expect_not_contains() gives useful message on failure", {
+  x1 <- c("a", "b", "c")
+  x2 <- c("c", "d")
+  x3 <- c("b", "c", "d")
+
+  expect_snapshot_failure(expect_not_contains(x1, x2))
+  expect_snapshot_failure(expect_not_contains(x1, x3))
+})
+
 
 # in ----------------------------------------------------------------