[tarantool-patches] [PATCH v1 1/1] tap: fix is_deeply box.NULL corner cases

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

The tap:is_deeply call used to return inconsistent result
processing an empty tuple and tuple that has no values:
is_deeply({a = box.NULL}, {})  == true
is_deeply({}, {a = box.NULL}) == false
Fixed to return true in such case.

We shouldn't return false in such case because of marshaling
features covered by tests:
is_deeply(decode(encode(t)), t) must be true for all t,
including t = nil; decode(encode(nil)) == box.NULL.

Closes #4125
---
Branch: http://github.com/tarantool/tarantool/tree/kshch/gh-4125-inconsistent-isdeeply-results
Issue: https://github.com/tarantool/tarantool/issues/4125

 src/lua/tap.lua           |  4 ++--
 test/app-tap/tap.result   |  8 ++++++--
 test/app-tap/tap.test.lua | 10 +++++++++-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/lua/tap.lua b/src/lua/tap.lua
index 546d15392..4f214ba52 100644
--- a/src/lua/tap.lua
+++ b/src/lua/tap.lua
@@ -117,8 +117,8 @@ local function cmpdeeply(got, expected, extra)
     end
 
     -- check if expected contains more keys then got
-    for i, _ in pairs(expected) do
-        if visited_keys[i] ~= true then
+    for i, v in pairs(expected) do
+        if visited_keys[i] ~= true and v ~= nil then
             extra.expected = 'key ' .. tostring(i)
             extra.got = 'nil'
             return false
diff --git a/test/app-tap/tap.result b/test/app-tap/tap.result
index 3e7882331..dced9a5a2 100644
--- a/test/app-tap/tap.result
+++ b/test/app-tap/tap.result
@@ -119,7 +119,7 @@ not ok - failed subtests
   failed: 1
   ...
     # is_deeply
-    1..6
+    1..10
     ok - 1 and 1
     ok - abc and abc
     ok - empty tables
@@ -136,10 +136,14 @@ not ok - failed subtests
       expected: 5
       got: 4
       ...
+    ok - {} and {a = nil}
+    ok - {a = nil} and {}
+    ok - {a = nil} and {b = nil}
+    ok - {a = nil} and {b = nil, c = nil}
     # is_deeply: end
 not ok - failed subtests
   ---
-  planned: 6
+  planned: 10
   failed: 2
   ...
     # like
diff --git a/test/app-tap/tap.test.lua b/test/app-tap/tap.test.lua
index 0e1de7f1c..c0593db46 100755
--- a/test/app-tap/tap.test.lua
+++ b/test/app-tap/tap.test.lua
@@ -118,7 +118,7 @@ end)
 
 
 test:test('is_deeply', function(t)
-    t:plan(6)
+    t:plan(10)
 
     t:is_deeply(1, 1, '1 and 1')
     t:is_deeply('abc', 'abc', 'abc and abc')
@@ -127,6 +127,14 @@ test:test('is_deeply', function(t)
     t:is_deeply({1}, {2}, '{1} and {2}')
     t:is_deeply({1, 2, { 3, 4 }}, {1, 2, { 3, 5 }}, '{1,2,{3,4}} and {1,2,{3,5}}')
 
+    --
+    -- gh-4125: is_deeply inconsistently works with box.NULL.
+    --
+    t:is_deeply({}, {a = box.NULL}, '{} and {a = nil}')
+    t:is_deeply({a = box.NULL}, {}, '{a = nil} and {}')
+    t:is_deeply({a = box.NULL}, {b = box.NULL}, '{a = nil} and {b = nil}')
+    t:is_deeply({a = box.NULL}, {b = box.NULL, c = box.NULL},
+                '{a = nil} and {b = nil, c = nil}')
 end)
 
 
-- 
2.21.0