WIP: PoC of filtering over 1:1 connections borders

Related to #39.

Author: Totktonada

graphql/accessor_general.lua

@@ -756,6 +756,8 @@ end
 ---   `offset` arqument of the GraphQL query),
 --- * `resulting_object_cnt_max` (number),
 --- * `fetched_object_cnt_max` (number).
+--- * `fields` (table) XXX
+--- * `info` (table) XXX
 ---
 --- @return nil
 ---
@@ -779,6 +781,8 @@ local function process_tuple(state, tuple, opts)
            'query execution timeout exceeded, use `timeout_ms` to increase it')
     local collection_name = opts.collection_name
     local pcre = opts.pcre
+    local fields = opts.fields
+    local info = opts.info
 
     -- convert tuple -> object
     local obj = opts.unflatten_tuple(collection_name, tuple,
@@ -792,6 +796,13 @@ local function process_tuple(state, tuple, opts)
         return true -- skip pivot item too
     end
 
+    -- make subrequests if needed
+    for k, v in pairs(filter) do
+        if obj[k] == nil and fields[k] ~= nil then
+            obj[k] = fields[k].resolve(obj, {}, info)
+        end
+    end
+
     -- filter out non-matching objects
     local match = utils.is_subtable(obj, filter) and
         match_using_re(obj, pcre)
@@ -918,6 +929,8 @@ local function select_internal(self, collection_name, from, filter, args, extra)
         unflatten_tuple = self.funcs.unflatten_tuple,
         default_unflatten_tuple = default_unflatten_tuple,
         pcre = args.pcre,
+        fields = extra.fields,
+        info = extra.info,
     }
 
     if index == nil then

graphql/tarantool_graphql.lua

@@ -323,6 +323,7 @@ gql_type = function(state, avro_schema, collection, collection_name)
             assert(destination_type ~= nil,
                 ('destination_type (named %s) must not be nil'):format(
                 c.destination_collection))
+            local raw_destination_type = destination_type
 
             local c_args
             if c.type == '1:1' then
@@ -408,7 +409,11 @@ gql_type = function(state, avro_schema, collection, collection_name)
                         destination_args_values = destination_args_values,
                     }
                     local extra = {
-                        qcontext = info.qcontext
+                        qcontext = info.qcontext,
+                        -- XXX: add only those fields that are for 1:1 or 1:1*
+                        -- connections or even table of its resolve function
+                        fields = raw_destination_type.fields,
+                        info = info, -- for subrequests
                     }
                     local object_args_instance = {} -- passed to 'filter'
                     local list_args_instance = {} -- passed to 'args'
@@ -433,6 +438,9 @@ gql_type = function(state, avro_schema, collection, collection_name)
                         -- we expect here exactly one object even for 1:1*
                         -- connections because we processed all-parts-are-null
                         -- situation above
+
+                        -- XXX: what when a filter passed and no one object
+                        -- matched?
                         assert(#objs == 1,
                             'expect one matching object, got ' ..
                             tostring(#objs))
@@ -596,6 +604,24 @@ local function parse_cfg(cfg)
         state.list_arguments[collection_name] = list_args
         state.all_arguments[collection_name] = args
     end
+
+    -- add arguments for 1:1 and 1:1* connections for each collection type
+    for collection_name, collection in pairs(state.collections) do
+        for _, c in ipairs(collection.connections or {}) do
+            local destination_type =
+                state.nullable_collection_types[c.destination_collection]
+            if c.type == '1:1' or c.type == '1:1*' then
+                state.all_arguments[collection_name][c.name] =
+                    types.inputObject({
+                        name = c.name,
+                        description = 'generated from the connection ' ..
+                            c.name,
+                        fields = destination_type.fields,
+                    }
+                )
+            end
+        end
+    end
     -- create fake root `Query` collection
     create_root_collection(state)
     return state
@@ -722,6 +748,7 @@ end
 ---                 -- query; by now it consists of a single qcontext table,
 ---                 -- which can be used by accessor to store any query-related
 ---                 -- data
+---                 -- XXX: extra.fields, extra.info
 ---                 --
 ---                 return ...
 ---             end,

test/local/space_nested_args.result

@@ -0,0 +1,17 @@
+RESULT
+---
+order_collection:
+- order_id: order_id_1
+  description: first order of Ivan
+  user_connection:
+    user_id: user_id_1
+    last_name: Ivanov
+    first_name: Ivan
+- order_id: order_id_2
+  description: second order of Ivan
+  user_connection:
+    user_id: user_id_1
+    last_name: Ivanov
+    first_name: Ivan
+...
+

test/local/space_nested_args.test.lua

@@ -0,0 +1,91 @@
+#!/usr/bin/env tarantool
+
+local fio = require('fio')
+
+-- require in-repo version of graphql/ sources despite current working directory
+package.path = fio.abspath(debug.getinfo(1).source:match("@?(.*/)")
+    :gsub('/./', '/'):gsub('/+$', '')) .. '/../../?.lua' .. ';' ..
+    package.path
+
+local yaml = require('yaml')
+local graphql = require('graphql')
+local utils = require('graphql.utils')
+local testdata = require('test.testdata.common_testdata')
+
+-- init box, upload test data and acquire metadata
+-- -----------------------------------------------
+
+-- init box and data schema
+box.cfg{background = false}
+testdata.init_spaces()
+
+-- upload test data
+testdata.fill_test_data()
+
+-- acquire metadata
+local metadata = testdata.get_test_metadata()
+local schemas = metadata.schemas
+local collections = metadata.collections
+local service_fields = metadata.service_fields
+local indexes = metadata.indexes
+
+-- build accessor and graphql schemas
+-- ----------------------------------
+
+local accessor = graphql.accessor_space.new({
+    schemas = schemas,
+    collections = collections,
+    service_fields = service_fields,
+    indexes = indexes,
+})
+
+local gql_wrapper = graphql.new({
+    schemas = schemas,
+    collections = collections,
+    accessor = accessor,
+})
+
+-- run queries
+-- -----------
+
+local function print_and_return(...)
+    print(...)
+    return table.concat({...}, ' ') .. '\n'
+end
+
+local function run_queries(gql_wrapper)
+    local results = ''
+
+    local query_1 = [[
+        query user_by_order($user_id: String) {
+            order_collection(user_connection: {user_id: $user_id}) {
+                order_id
+                description
+                user_connection {
+                    user_id
+                    last_name
+                    first_name
+                }
+            }
+        }
+    ]]
+
+    utils.show_trace(function()
+        local variables_1 = {user_id = 'user_id_1'}
+        local gql_query_1 = gql_wrapper:compile(query_1)
+        local result = gql_query_1:execute(variables_1)
+        results = results .. print_and_return(
+            ('RESULT\n%s'):format(yaml.encode(result)))
+    end)
+
+    return results
+end
+
+run_queries(gql_wrapper)
+
+-- clean up
+-- --------
+
+testdata.drop_spaces()
+
+os.exit()