GraphQL silently cast huge cdata numbers to null

[olegrok]

in code:

object.version = -1ULL

in query such field silently return null.

[rosik]

Could you provide a more detailed description, please? Is it still relevant, by the way?

[Totktonada]

@olegrok Friendly reminder. I don't understand the issue and have no idea how to reproduce it.

I made some attempts, but can't deduce anything useful from them.

diff --git a/test/integration/graphql_test.lua b/test/integration/graphql_test.lua
index 6462450..a79f17d 100644
--- a/test/integration/graphql_test.lua
+++ b/test/integration/graphql_test.lua
@@ -2147,3 +2147,60 @@ function g.test_non_finite_float()
             query_schema, nil, nil, {variables = variables})
     end
 end
+
+function g.test_huge_cdata_number()
+     local query = [[
+        query ($x: Long!) { test(arg: $x) }
+    ]]
+
+    local function callback(_, args)
+        return args[1].value
+    end
+
+    local query_schema = {
+        ['test'] = {
+            kind = types.long.nonNull,
+            arguments = {
+                arg = types.long.nonNull,
+            },
+            resolve = callback,
+        }
+    }
+
+    -- 2^64-1
+    --[[
+    local variables = {x = 18446744073709551615ULL}
+    local res = check_request(query, query_schema, nil, nil, {variables = variables})
+    -- Raises:
+    -- > Wrong variable "x" for the Scalar "Long"
+    t.assert_type(res, 'table')
+    t.assert_equals(res.test, 18446744073709551615ULL)
+    --]]
+
+    -- 2^52-1: maximum allowed by the specification of Long.
+    --
+    -- https://github.com/tarantool/graphql/wiki/Long
+    local variables = {x = 4503599627370495ULL}
+    local res = check_request(query, query_schema, nil, nil, {variables = variables})
+    t.assert_type(res, 'table')
+    t.assert_equals(res.test, 4503599627370495ULL)
+    -- Succeeds.
+
+    -- 2^63-1: de-facto maximum.
+    --
+    -- I don't know why something out of the specification is
+    -- accepted.
+    --
+    -- OTOH, I don't know why the specification shrinks the range
+    -- to [-2^52; 2^52 - 1]. I mean, well, `number` Lua type
+    -- represents integral numbers precisely only in this
+    -- range[^1], but larger values are representable with cdata
+    -- numbers.
+    --
+    -- [^1]: [-2^53; 2^53] in fact.
+    local variables = {x = 9223372036854775807ULL}
+    local res = check_request(query, query_schema, nil, nil, {variables = variables})
+    t.assert_type(res, 'table')
+    t.assert_equals(res.test, 9223372036854775807ULL)
+    -- Succeeds.
+end

(My version of the module is 0.1.4.)

[olegrok]

My example will be related to TDG.
I have following schema:

local user_schema = types.object{
    name = 'UserSchema',
    fields = {
        uid = types.string.nonNull,
        email = types.string.nonNull,
        login = types.string.nonNull,
        username = types.string.nonNull,
        created_at = types.long.nonNull,
        last_login = types.long,
        state = types.string.nonNull,
        state_reason = types.string,
        role = types.string.nonNull,
        roles = types.list(types.string.nonNull),
        expires_in = types.long.nonNull,
        last_password_update_time = types.long,
        failed_login_attempts = types.long.nonNull,
        unblocked_at = types.long,
        tenant = types.string,
    },
    description = 'User info',
    schema = 'admin',
}

local self_user = types.object{
        name='GraphqlUser',
        description='Graphql authorization info',
        fields = {
            user = user_schema,
        },
    }

graphql.add_callback({
        schema='admin',
        prefix = 'user',
        name = 'self',
        doc = 'Returns if access granted and current logged user. ' ..
            'If user is null than access granted by anonymous or token',
        args = {},
        kind = self_user,
        callback = 'common.admin.users.self',
    })

Then I write simple function:

local function user_self(_, _)
    if true then
        return {
            user = { unblocked_at = 1000 },
        }
    end
end

It works fine:

But after I change 1000 to "-1ULL" (the same as 18446744073709551615ULL) I have following result:

Actually it works fine with "-1ULL / 2" but starts to return null since "-1ULL / 2 + 1"

[no1seman]

tarantool> ffi=require('ffi'); a=-1ULL; print(a); print(type(a)); print(ffi.istype('uint64_t', a)); tonumber64('-1ULL')
18446744073709551615ULL
cdata
true
---
...

seems that the problem is in tonumber64() because for unknown reason -1ULL becomes 'uint64_t' instead of 'int64_t'

also may be related to: tarantool/tarantool#4738