Add assert_one_of

Author: yngvar-antonsson

CHANGELOG.md

@@ -50,6 +50,7 @@
 - Raise an error in the `Server:wait_for_condition()` function when
   the server process is terminated. This is useful to not wait for timeout, for example,
   when a server fails to start due to bad configuration.
+- Add `assert_one_of`.
 
 ## 0.5.7
 

README.rst

@@ -170,6 +170,8 @@ List of luatest functions
 +--------------------------------------------------------------------+-----------------------------------------------+
 | ``assert_covers (actual, expected[, message])``                    | Checks that actual map includes expected one. |
 +--------------------------------------------------------------------+-----------------------------------------------+
+| ``assert_one_of (actual, expected[, message])``                    | Checks that value is of on alternatives.      |
++--------------------------------------------------------------------+-----------------------------------------------+
 | ``assert_lt (left, right[, message])``                             | Compare numbers.                              |
 +--------------------------------------------------------------------+-----------------------------------------------+
 | ``assert_le (left, right[, message])``                             |                                               |

luatest/assertions.lua

@@ -276,6 +276,25 @@ function M.assert_ge(left, right, message)
     end
 end
 
+--- Check that value is one of alternates.
+--
+-- @param actual
+-- @param expected
+-- @string[opt] message
+function M.assert_one_of(actual, expected, message)
+    local res = false
+    for _, v in ipairs(expected) do
+        if comparator.equals(actual, v) then
+            res = true
+            break
+        end
+    end
+    if not res then
+        local str_actual, str_expected = prettystr_pairs(actual, expected)
+        fail_fmt(2, message, 'Assertion failed: %s must be one of %s', str_actual, str_expected)
+    end
+end
+
 --- Check that two values are not equal.
 -- Tables are compared by value.
 --

test/luaunit/assertions_test.lua

@@ -969,6 +969,16 @@ function g.test_assertTableAdditions()
     t.assert_not_equals({1,x=2,3,y=4}, {1,x=2,3})
 end
 
+function g.test_assert_one_of()
+    t.assert_one_of(1, {1,2,3})
+    t.assert_one_of({1}, {{1},{2},{3}})
+    t.assert_one_of("two", {"one", "two"})
+
+    assert_failure_contains("oh no", t.assert_one_of, 1, {2,3}, "oh no")
+    assert_failure_contains("Assertion failed: 1 must be one of {2, 3}", t.assert_one_of, 1, {2,3})
+    assert_failure_contains("Assertion failed: {1} must be one of {{2}, {3}}", t.assert_one_of, {1}, {{2},{3}})
+end
+
 g.test_assert_comparisons = function()
     -- assert_lt
     t.assert_lt(1.9, 2)