Add linking entity option on m2m

README.md

@@ -173,6 +173,9 @@ main()
 
   - Arguments
     - `config` (object, optional) - A configuration object with the following schema.
+      - `defaultArgsAdapter` (function, optional) - The default `argsAdapter` function for the entities.
+      - `addEntitiesResolvers` (boolean, optional) - automatically add entities types and resolvers  accordingly with configuration, see [composer entities section](#composer-entities).
+      - `logger` TODO
       - `subgraphs` (array, optional) - Array of subgraph configuration objects with the following schema.
         - `name` (string, optional) - A unique name to identify the subgraph; if missing the default one is `#${index}`, where index is the subgraph index in the array.
         - `server` (object, required) - Configuration object for communicating with the subgraph server with the following schema:
@@ -195,11 +198,12 @@ main()
             - `resolver` (object, optional) - The resolver definition to query the foreing entity, same structure as `entity.resolver`.
           - `many` (array of objects, optional) - Describe a 1-to-many relation - the reverse of the foreign key.
             - `type` (string, required) - The entity type where the entity is a foreign key.
-            - `fkey` (string, required) - The foreign key field in the referred entity.
+            - `fkey` (string, optional) - The foreign key field in the referred entity. TODO Required but not on `link`
             - `as` (string, required) - When using `addEntitiesResolvers`, it defines the name of the relation as a field of the current one, as a list.
             - `pkey` (string, optional) - The primary key of the referred entity.
             - `subgraph` (string, optional) - The subgraph name of the referred entity, where the resolver is located; if missing is intended the self.
             - `resolver` (object, required) - The resolver definition to query the referred entity, same structure as `entity.resolver`.
+            - `link` TODO
       - `onSubgraphError` (function, optional) - Hook called when an error occurs getting schema from a subgraph. The default function will throw the error. The arguments are:
           - `error` (error) - The error.
           - `subgraph` (string) - The erroring subgraph name.
@@ -221,8 +225,6 @@ main()
       - `queryTypeName` (string, optional) - The name of the `Query` type in the composed schema. **Default:** `'Query'`.
       - `mutationTypeName` (string, optional) - The name of the `Mutation` type in the composed schema. **Default:** `'Mutation'`.
       - `subscriptionTypeName` (string, optional) - The name of the `Subscription` type in the composed schema. **Default:** `'Subscription'`.
-      - `defaultArgsAdapter` (function, optional) - The default `argsAdapter` function for the entities.
-      - `addEntitiesResolvers` (boolean, optional) - automatically add entities types and resolvers accordingly with configuration, see [composer entities section](#composer-entities).
 
   - Returns
     - A `Promise` that resolves with a `Composer` instance.

fixtures/artists-subgraph-with-entities.js

@@ -91,4 +91,4 @@ const entities = {
   }
 }
 
-module.exports = { name: 'artists', schema, reset, resolvers, entities, data }
+module.exports = { name: 'artists-subgraph', schema, reset, resolvers, entities, data }

fixtures/foods-subgraph.js

@@ -0,0 +1,70 @@
+'use strict'
+
+const schema = `
+  input WhereConditionIn {
+    in: [ID!]!
+  }
+
+  input FoodsWhereCondition {
+    id: WhereConditionIn
+  } 
+
+  type Food {
+    id: ID!
+    name: String
+  }
+
+  type Query {
+    foods(where: FoodsWhereCondition): [Food]
+  }
+`
+
+const data = {
+  foods: null
+}
+
+function reset () {
+  data.foods = {
+    50: {
+      id: 50,
+      name: 'Pizza margherita'
+    },
+    51: {
+      id: 51,
+      name: 'Pizza boscaiola'
+    },
+    52: {
+      id: 52,
+      name: 'Pizza capricciosa'
+    },
+    60: {
+      id: 60,
+      name: 'Spaghetti carbonara'
+    },
+    61: {
+      id: 61,
+      name: 'Tagliolini scoglio'
+    },
+    62: {
+      id: 62,
+      name: 'Pici cacio e pepe'
+    },
+    63: {
+      id: 63,
+      name: 'Grigliata mista'
+    }
+  }
+}
+
+reset()
+
+const resolvers = {
+  Query: {
+    foods (_, { where }) {
+      return Object.values(data.foods)
+        .filter(a => where.id.in.includes(String(a.id)))
+    }
+  }
+}
+
+module.exports = { name: 'foods-subgraph', schema, reset, resolvers, data }

fixtures/movies-subgraph-with-entities.js

@@ -100,4 +100,4 @@ const entities = {
   }
 }
 
-module.exports = { name: 'movies', schema, reset, resolvers, entities, data }
+module.exports = { name: 'movies-subgraph', schema, reset, resolvers, entities, data }

fixtures/restaurants-subgraph.js

@@ -0,0 +1,112 @@
+'use strict'
+
+const schema = `
+  input WhereConditionIn {
+    in: [ID!]!
+  }
+
+  input RestaurantsWhereCondition {
+    id: WhereConditionIn
+  } 
+
+  input RestaurantsFoodsWhereCondition {
+    restaurantId: WhereConditionIn
+    foodId: WhereConditionIn
+  } 
+
+  type Restaurant {
+    id: ID!
+    businessName: String
+  }
+
+  type RestaurantsFoods {
+    restaurantId: ID!
+    foodId: ID!
+  }
+
+  type Query {
+    restaurants(where: RestaurantsWhereCondition): [Restaurant]
+    restaurantsFoods(where: RestaurantsFoodsWhereCondition): [RestaurantsFoods]
+  }
+`
+
+const data = {
+  restaurants: null
+}
+
+function reset () {
+  data.restaurantsFoods = [
+    {
+      restaurantId: 90,
+      foodId: 50
+    },
+    {
+      restaurantId: 90,
+      foodId: 51
+    },
+    {
+      restaurantId: 90,
+      foodId: 52
+    },
+
+    {
+      restaurantId: 91,
+      foodId: 60
+    },
+    {
+      restaurantId: 91,
+      foodId: 61
+    },
+    {
+      restaurantId: 91,
+      foodId: 62
+    },
+
+    {
+      restaurantId: 92,
+      foodId: 60
+    },
+    {
+      restaurantId: 92,
+      foodId: 63
+    }
+  ]
+
+  data.restaurants = {
+    90: {
+      id: 90,
+      businessName: 'Pizzeria Napoletana'
+    },
+    91: {
+      id: 91,
+      businessName: 'Ristorante Stellato'
+    },
+    92: {
+      id: 92,
+      businessName: 'Trattoria da Gigi'
+    }
+  }
+}
+
+reset()
+
+const resolvers = {
+  Query: {
+    restaurants (_, { where }) {
+      return Object.values(data.restaurants)
+        .filter(r => where.id.in.includes(String(r.id)))
+    },
+    restaurantsFoods (_, { where }) {
+      if (where.restaurantId?.in) {
+        return data.restaurantsFoods
+          .filter(rf => where.restaurantId.in.includes(String(rf.restaurantId)))
+      }
+      if (where.foodId?.in) {
+        return data.restaurantsFoods
+          .filter(rf => where.foodId.in.includes(String(rf.foodId)))
+      }
+    }
+  }
+}
+
+module.exports = { name: 'restaurants-subgraph', schema, reset, resolvers, data }

fixtures/songs-subgraph-with-entities.js

@@ -100,4 +100,4 @@ const entities = {
   }
 }
 
-module.exports = { name: 'songs', schema, reset, resolvers, entities, data }
+module.exports = { name: 'songs-subgraph', schema, reset, resolvers, entities, data }