fix: entities resolution (#29)

* fix: entities resolution

* chore: fix test skip

fixtures/artists-subgraph.js

@@ -0,0 +1,60 @@
+'use strict'
+
+const schema = `
+  type Artist {
+    id: ID
+    firstName: String
+    lastName: String
+    profession: String
+  }
+
+  type Query {
+    artists(ids: [ID!]!): [Artist]
+  }
+`
+
+const data = {
+  artists: null
+}
+
+function reset () {
+  data.artists = {
+    101: {
+      id: 101,
+      firstName: 'Christopher',
+      lastName: 'Nolan',
+      profession: 'Director'
+    },
+    102: {
+      id: 102,
+      firstName: 'Roberto',
+      lastName: 'Benigni',
+      profession: 'Director'
+    },
+    103: {
+      id: 103,
+      firstName: 'Brian',
+      lastName: 'Molko',
+      profession: 'Singer'
+    }
+  }
+}
+
+reset()
+
+const resolvers = {
+  Query: {
+    artists (_, { ids }) {
+      return Object.values(data.artists).filter(a => ids.includes(String(a.id)))
+    }
+  }
+}
+
+const entities = {
+  Artist: {
+    referenceListResolverName: 'artists',
+    keys: [{ field: 'id' }]
+  }
+}
+
+module.exports = { name: 'artists', schema, reset, resolvers, entities, data }

fixtures/movies-subgraph.js

@@ -0,0 +1,90 @@
+'use strict'
+
+const schema = `
+  type Movie {
+    id: ID!
+    title: String
+    directorId: ID
+  }
+
+  type Query {
+    movies(ids: [ID!]!): [Movie]
+  }
+
+  type Artist {
+    id: ID
+    movies: [Movie]
+  }
+
+  extend type Movie {
+    director: Artist
+  }
+
+  extend type Query {
+    movieArtists (ids: [ID!]!): [Artist]
+  }
+`
+
+const data = {
+  movies: null
+}
+
+function reset () {
+  data.movies = {
+    10: {
+      id: 10,
+      title: 'Interstellar',
+      directorId: 101
+    },
+    11: {
+      id: 11,
+      title: 'Oppenheimer',
+      directorId: 101
+    },
+    12: {
+      id: 12,
+      title: 'La vita é bella',
+      directorId: 102
+    }
+  }
+}
+
+reset()
+
+const resolvers = {
+  Query: {
+    movies (_, { ids }) {
+      return Object.values(data.movies).filter(a => ids.includes(String(a.id)))
+    },
+    movieArtists: async (parent, args, context, info) => {
+      return args.ids.map(id => ({ id }))
+    }
+  },
+  Movie: {
+    director: (parent, args, context, info) => {
+      return parent?.directorId ? { id: parent.directorId } : null
+    }
+  },
+  Artist: {
+    // TODO dataloader here
+    movies: (parent, args, context, info) => {
+      return Object.values(data.songs).filter(a => String(a.directorId) === String(parent.id))
+    }
+  }
+}
+
+const entities = {
+  Movie: {
+    referenceListResolverName: 'movies',
+    keys: [{ field: 'id' }, { field: 'directorId', type: 'Artist' }]
+  },
+  Artist: {
+    referenceListResolverName: 'movieArtists',
+    argsAdapter: (partialResults) => {
+      return { ids: partialResults.map(r => r.id) }
+    },
+    keys: [{ field: 'id' }]
+  }
+}
+
+module.exports = { name: 'movies', schema, reset, resolvers, entities, data }

fixtures/songs-subgraph.js

@@ -0,0 +1,90 @@
+'use strict'
+
+const schema = `
+  type Song {
+    id: ID!
+    title: String
+    singerId: ID
+  }
+
+  type Query {
+    songs(ids: [ID!]!): [Song]
+  }
+
+  type Artist {
+    id: ID
+    songs: [Song]
+  }
+
+  extend type Song {
+    singer: Artist
+  }
+
+  extend type Query {
+    songArtists (ids: [ID!]!): [Artist]
+  }
+`
+
+const data = {
+  songs: null
+}
+
+function reset () {
+  data.songs = {
+    1: {
+      id: 1,
+      title: 'Every you every me',
+      singerId: 103
+    },
+    2: {
+      id: 2,
+      title: 'The bitter end',
+      singerId: 103
+    },
+    3: {
+      id: 3,
+      title: 'Vieni via con me',
+      singerId: 102
+    }
+  }
+}
+
+reset()
+
+const resolvers = {
+  Query: {
+    async songs (_, { ids }) {
+      return Object.values(data.songs).filter(a => ids.includes(String(a.id)))
+    },
+    songArtists: async (parent, args, context, info) => {
+      return args.ids.map(id => ({ id }))
+    }
+  },
+  Song: {
+    singer: (parent, args, context, info) => {
+      return parent?.singerId ? { id: parent.singerId } : null
+    }
+  },
+  Artist: {
+    // TODO dataloader here
+    songs: (parent, args, context, info) => {
+      return Object.values(data.songs).filter(a => String(a.singerId) === String(parent.id))
+    }
+  }
+}
+
+const entities = {
+  Song: {
+    referenceListResolverName: 'songs',
+    keys: [{ field: 'id' }, { field: 'singerId', type: 'Artist' }]
+  },
+  Artist: {
+    referenceListResolverName: 'songArtists',
+    argsAdapter: (partialResults) => {
+      return { ids: partialResults.map(r => r.id) }
+    },
+    keys: [{ field: 'id' }]
+  }
+}
+
+module.exports = { name: 'songs', schema, reset, resolvers, entities, data }

lib/composer.js

@@ -6,7 +6,7 @@ const { SubscriptionClient } = require('@mercuriusjs/subscription-client')
 const { createEmptyObject, unwrapSchemaType } = require('./graphql-utils')
 const { fetchSubgraphSchema, makeGraphqlRequest } = require('./network')
 const { QueryBuilder } = require('./query-builder')
-const { isObject, keySelection, createDefaultArgsAdapter } = require('./utils')
+const { isObject, keySelection, createDefaultArgsAdapter, traverseResult } = require('./utils')
 const {
   validateArray,
   validateFunction,
@@ -533,6 +533,7 @@ function mergeResults (query, partialResult, response) {
 
     for (let i = 0; i < mergedPartial.length; i++) {
       const merging = mergedPartial[i]
+      if (!merging) { continue }
 
       // no need to be recursive
       if (Array.isArray(merging)) {
@@ -577,12 +578,7 @@ function selectResult (query, partialResult, response) {
 
     if (!mergedPartial && !mergedPartial[path]) { break }
 
-    const node = mergedPartial[path]
-    if (Array.isArray(mergedPartial)) {
-      mergedPartial = mergedPartial.map(r => r[path])
-      continue
-    }
-    mergedPartial = node
+    mergedPartial = traverseResult(mergedPartial, path)
   }
 
   if (!query.root) {