[tarantool-patches] Re: [PATCH][vshard] Check self passed to object methods

[Alex Khatskevich <avkhatskevich@tarantool.org>]

> 1. Please, beforehand describe the issue:
> -- 
> -- gh-####: issue description.
> -- 
Fixed
> 2. Why do you need table.sort here?
> 3. Why does not work just iteration over getmetatable(object).__index ?
Because as far as I know, the order of iteration over a dictionary is not
determined. However we need to keep order the same, so that test.result
file do not change.
> 4. Looks like you did not that I asked for. Please, do not use assert, 
> and do not
> inline part of check_self_arg. Make two functions: check_self_arg, 
> generate_checker
> or something.
You want the `generate_checker` to be a universal wrapper-function, 
which checks
any number of arguments (not only the first one). Is that right?
> 5. Still extra line.
Fixed
> 6. Please, fit the comment in 66 symbols.
Fixed


The whole diff:

commit c0b7847cb76802f0bbe839537a00d17dfc995eb5
Author: AKhatskevich <avkhatskevich@tarantool.org>
Date:   Fri Jun 1 14:58:51 2018 +0300

     Check self passed to object methods

     Changes:

     1. `check_self_arg` function wrapper added to utils.
     Its mechanics:
      * check that the first argument is of table type
      * return result of a real function

     2. Check, that self argument is passed to all replicaset and replica
     object methods.

     Closes: #81

diff --git a/test/router/router.result b/test/router/router.result
index 5fcabc6..635b63c 100644
--- a/test/router/router.result
+++ b/test/router/router.result
@@ -977,6 +977,80 @@ util.check_error(vshard.router.sync, "xxx")
  vshard.router.sync(100500)
  ---
  ...
+--
+-- gh-81: Check that user passed self arg.
+-- This check ensures that in case a vshard user called an
+-- object method like this: object.method() instead of
+-- object:method(), an appropriate help-error returns.
+--
+_, replicaset = next(vshard.router.internal.replicasets)
+---
+...
+error_messages = {}
+---
+...
+test_run:cmd("setopt delimiter ';'")
+---
+- true
+...
+get_object_method_names = function(object)
+    local res = {}
+    for name, _ in pairs(getmetatable(object).__index) do
+        table.insert(res, name)
+    end
+    table.sort(res)
+    return res
+end;
+---
+...
+for _, func_name in pairs(get_object_method_names(replicaset)) do
+    local ok, msg = pcall(replicaset[func_name], "arg_of_wrong_type")
+    table.insert(error_messages, msg:match("Use .*"))
+end;
+---
+...
+test_run:cmd("setopt delimiter ''");
+---
+- true
+...
+error_messages
+---
+- - Use replicaset:call(...) instead of replicaset.call(...)
+  - Use replicaset:callro(...) instead of replicaset.callro(...)
+  - Use replicaset:callrw(...) instead of replicaset.callrw(...)
+  - Use replicaset:connect(...) instead of replicaset.connect(...)
+  - Use replicaset:connect_all(...) instead of replicaset.connect_all(...)
+  - Use replicaset:connect_master(...) instead of 
replicaset.connect_master(...)
+  - Use replicaset:connect_replica(...) instead of 
replicaset.connect_replica(...)
+  - Use replicaset:down_replica_priority(...) instead of 
replicaset.down_replica_priority(...)
+  - Use replicaset:rebind_connections(...) instead of 
replicaset.rebind_connections(...)
+  - Use replicaset:up_replica_priority(...) instead of 
replicaset.up_replica_priority(...)
+...
+_, replica = next(replicaset.replicas)
+---
+...
+error_messages = {}
+---
+...
+test_run:cmd("setopt delimiter ';'")
+---
+- true
+...
+for _, func_name in pairs(get_object_method_names(replica)) do
+    local ok, msg = pcall(replica[func_name], "arg_of_wrong_type")
+    table.insert(error_messages, msg:match("Use .*"))
+end;
+---
+...
+test_run:cmd("setopt delimiter ''");
+---
+- true
+...
+error_messages
+---
+- - Use replica:is_connected(...) instead of replica.is_connected(...)
+  - Use replica:safe_uri(...) instead of replica.safe_uri(...)
+...
  _ = test_run:cmd("switch default")
  ---
  ...
diff --git a/test/router/router.test.lua b/test/router/router.test.lua
index ebf0eb5..ff77176 100644
--- a/test/router/router.test.lua
+++ b/test/router/router.test.lua
@@ -361,6 +361,43 @@ vshard.router.sync()
  util.check_error(vshard.router.sync, "xxx")
  vshard.router.sync(100500)

+--
+-- gh-81: Check that user passed self arg.
+-- This check ensures that in case a vshard user called an
+-- object method like this: object.method() instead of
+-- object:method(), an appropriate help-error returns.
+--
+_, replicaset = next(vshard.router.internal.replicasets)
+error_messages = {}
+
+test_run:cmd("setopt delimiter ';'")
+get_object_method_names = function(object)
+    local res = {}
+    for name, _ in pairs(getmetatable(object).__index) do
+        table.insert(res, name)
+    end
+    table.sort(res)
+    return res
+end;
+
+for _, func_name in pairs(get_object_method_names(replicaset)) do
+    local ok, msg = pcall(replicaset[func_name], "arg_of_wrong_type")
+    table.insert(error_messages, msg:match("Use .*"))
+end;
+test_run:cmd("setopt delimiter ''");
+error_messages
+
+_, replica = next(replicaset.replicas)
+error_messages = {}
+
+test_run:cmd("setopt delimiter ';'")
+for _, func_name in pairs(get_object_method_names(replica)) do
+    local ok, msg = pcall(replica[func_name], "arg_of_wrong_type")
+    table.insert(error_messages, msg:match("Use .*"))
+end;
+test_run:cmd("setopt delimiter ''");
+error_messages
+
  _ = test_run:cmd("switch default")
  test_run:drop_cluster(REPLICASET_2)

diff --git a/vshard/replicaset.lua b/vshard/replicaset.lua
index d210973..ede53c7 100644
--- a/vshard/replicaset.lua
+++ b/vshard/replicaset.lua
@@ -48,6 +48,7 @@ local lerror = require('vshard.error')
  local fiber = require('fiber')
  local luri = require('uri')
  local ffi = require('ffi')
+local csa = require('vshard.util').check_self_arg

  --
  -- on_connect() trigger for net.box
@@ -364,30 +365,39 @@ end
  --
  local replicaset_mt = {
      __index = {
-        connect = replicaset_connect_master;
-        connect_master = replicaset_connect_master;
-        connect_all = replicaset_connect_all;
-        connect_replica = replicaset_connect_to_replica;
-        rebind_connections = replicaset_rebind_connections;
-        down_replica_priority = replicaset_down_replica_priority;
-        up_replica_priority = replicaset_up_replica_priority;
-        call = replicaset_master_call;
-        callrw = replicaset_master_call;
-        callro = replicaset_nearest_call;
+        connect = csa("replicaset", "connect", replicaset_connect_master);
+        connect_master = csa("replicaset", "connect_master",
+                             replicaset_connect_master);
+        connect_all = csa("replicaset", "connect_all", 
replicaset_connect_all);
+        connect_replica = function(rs, r)
+            assert(type(rs) == "table" and type(r) == "table",
+                   'Use replicaset:connect_replica(...) instead of ' ..
+                   'replicaset.connect_replica(...)')
+            return replicaset_connect_to_replica(rs, r)
+        end;
+        rebind_connections = csa("replicaset", "rebind_connections",
+ replicaset_rebind_connections);
+        down_replica_priority = csa("replicaset", "down_replica_priority",
+ replicaset_down_replica_priority);
+        up_replica_priority = csa("replicaset", "up_replica_priority",
+ replicaset_up_replica_priority);
+        call = csa("replicaset", "call", replicaset_master_call);
+        callrw = csa("replicaset", "callrw", replicaset_master_call);
+        callro = csa("replicaset", "callro", replicaset_nearest_call);
      };
      __tostring = replicaset_tostring;
  }

  local replica_mt = {
      __index = {
-        is_connected = function(replica)
+        is_connected = csa("replica", "is_connected", function(replica)
              return replica.conn and replica.conn.state == 'active'
-        end,
-        safe_uri = function(replica)
+        end),
+        safe_uri = csa("replica", "safe_uri", function(replica)
              local uri = luri.parse(replica.uri)
              uri.password = nil
              return luri.format(uri)
-        end,
+        end),
      },
      __tostring = function(replica)
          if replica.name then
diff --git a/vshard/util.lua b/vshard/util.lua
index 184aad5..5b83260 100644
--- a/vshard/util.lua
+++ b/vshard/util.lua
@@ -48,7 +48,34 @@ local function reloadable_fiber_f(M, func_name, 
worker_name)
      end
  end

+--
+-- Wrap a given function to check that self argument is passed.
+-- New function returns an error in case one called a method
+-- like object.func instead of object:func.
+-- Returning wrapped function to a user and using raw functions
+-- inside of a module improves speed.
+-- This function can be used only in case the second argument is
+-- not of the "table" type.
+-- @param obj_name Name of the called object. Used only for error
+--        message construction.
+-- @param func_name Name of the called function. Used only for an
+--        error message construction.
+-- @param func A function which is about to be wrapped.
+--
+-- @retval Wrapped function.
+--
+local function check_self_arg(obj_name, func_name, func)
+    return function (self, ...)
+        if type(self) ~= "table" then
+            local fmt = 'Use %s:%s(...) instead of %s.%s(...)'
+            error(string.format(fmt, obj_name, func_name, obj_name, 
func_name))
+        end
+        return func(self, ...)
+    end
+end
+
  return {
      tuple_extract_key = tuple_extract_key,
      reloadable_fiber_f = reloadable_fiber_f,
+    check_self_arg = check_self_arg,
  }