Fix assert_covers treat arrays as maps

`assert_covers` now correctly treats arrays as scalars, ensuring
that one array is not considered to cover another unless they are
equal.

Closes #405

Author: mandesero

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Fixed a bug when `assert_covers` treats arrays as maps (gh-405).
 - Added the ability to keep and adjust cluster declarative configuration
   with `cluster:modify_config()` and apply it later via
   `cluster:apply_config_changes()` without passing an explicit

luatest/assertions.lua

@@ -443,6 +443,11 @@ local function table_slice(actual, expected)
     if type(expected) ~= 'table' or type(actual) ~= 'table' then
         return actual
     end
+
+    if utils.table_is_array(actual) or utils.table_is_array(expected) then
+        return actual
+    end
+
     local sliced = {}
     for k, _ in pairs(expected) do
         sliced[k] = table_slice(actual[k], expected[k])

luatest/utils.lua

@@ -242,4 +242,13 @@ function utils.pathjoin(a, b)
     return fio.pathjoin(a, b)
 end
 
+function utils.table_is_array(t)
+    local i = 0
+    for _ in pairs(t) do
+        i = i + 1
+        if t[i] == nil then return false end
+    end
+    return true
+end
+
 return utils

test/luatest_test.lua

@@ -105,21 +105,27 @@ end
 
 g.test_assert_covers = function()
     local subject = t.assert_covers
-    subject({a = 1, b = 2, c = 3}, {})
     subject({a = 1, b = 2, c = 3}, {a = 1})
     subject({a = 1, b = 2, c = 3}, {a = 1, c = 3})
     subject({a = 1, b = 2, c = 3}, {a = 1, b = 2, c = 3})
     subject({a = {b = 1, c = 2}}, {a = {b = 1}})
     subject({a = 1, b = {c = 2, d = {e = 3, f = 4}}}, {b = {d = {f = 4}}})
     subject({a = box.NULL}, {a = box.NULL})
     subject({a = box.tuple.new({1})}, {a = box.tuple.new({1})})
+    subject({1, 2}, {1, 2})
+    subject({[0] = 'zero', [1] = 'one'}, {[0] = 'zero'})
 
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 2})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 1, b = 1})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 1, b = 2, c = 3, d = 4})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {d = 1})
     helper.assert_failure(subject, {a = {b = 1, c = 2}}, {a = {b = 2, c = 2}})
     helper.assert_failure(subject, {a = {b = 1, c = 2}}, {a = {b = 1, c = 2, d = 3}})
+    helper.assert_failure(subject, {1, 2}, {})
+    helper.assert_failure(subject, {1, 2, 3}, {1, 2})
+    helper.assert_failure(subject, {1, 2, foo = 'bar'}, {1, 2})
+    helper.assert_failure(subject, {a = {1, 2, 3}}, {a = {1, 2}})
+    helper.assert_failure(subject, {a = {1, 2}}, {a = {}})
     helper.assert_failure(subject, {a = nil}, {a = box.NULL})
     helper.assert_failure(subject, {a = box.tuple.new({1})}, {a = box.tuple.new({2})})
     helper.assert_failure_contains('Argument 1 and 2 must be tables', subject, {a = 1, b = 2, c = 3}, nil)
@@ -133,7 +139,6 @@ g.test_assert_not_covers = function()
     subject({a = 1, b = 2, c = 3}, {d = 1})
     subject({a = nil}, {a = box.NULL})
 
-    helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 1})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 1, c = 3})
     helper.assert_failure(subject, {a = 1, b = 2, c = 3}, {a = 1, b = 2, c = 3})